LIMB-GIRDLE MUSCULAR DYSTROPHY (LGMD) SYNDROMES2Limb girdle dystrophies:Dominant1A: Myotilin; 5q31; Dysarthria1B: Lamin A/C; 1q21; + Cardiac1C: Caveolin-3; 3p25; Child onset1D: DNAJB6; 7q361E: Desmin; 2q351F: TNPO3; 7q321G: HNRPDL; 4q211H: 3p23Ankle contractures & High CKBethlem COL6A1: 21q22 COL6A2: 21q22 COL6A1: 2q37 COL12A1: 6q13Central core: RYR1; 19q13Cytoplasmic body: 2q24; 2q21 +...Distal myopathies MPD2: MATR3; 5q31Emery-Dreifuss Lamin A/C; 1q21 SYNE1; 6q25 SYNE2; 14q23Facioscapulohumeral 1A: DUX4; 4q35 1B: DUX4; 10qter 2: SMCHD1; 18p11Myofibrillar (Desmin storage) MFM1: Desmin; 2q35; AD or AR MFM2: CRYAB; 11q22 MFM3 (LGMD 1A): Myotilin; 5q31 MFM4: ZASP; 10q23 MFM5: Filamin C; 7q32 MFM6: BAG3; 10q25 Congenital: SEPN1; 1p36 OtherMyosin storage: MYH7; 14q11Myotonic (DM1): DMPK; 19q13Myotonic (DM2): ZNF9; 3q21Oculopharyngeal: PABP2; 14q11Limb girdle dystrophies:Recessive2A: Calpain-3 ;15q152B: Dysferlin; 2p13.12C: -Sarcoglycan; 13q122D: -Sarcoglycan; 17q212E: -Sarcoglycan; 4q122F: -Sarcoglycan; 5q332G: Telethonin; 17q122H: TRIM32; 9q332I(MDDGC5): FKRP; 19q132J: Titin; 2q242K(MDDGC1): POMT1; 9q342L: ANO5; 11p142M(MDDGC4): Fukutin; 9q312N(MDDGC2): POMT2; 14q242O(MDDGC3): POMGnT1; 1p322P(MDDGC7): DAG1; 3p212Q: Plectin 1f; 8q242R: Desmin; 2q352S: TRAPPC11; 4q35Caveolin-3Cerebellar hypoplasia: ISPD; 7p21 Merosin (Laminin 2) Absent: 6q22 Reduced Abnormal:LGMD 2IMyosclerosis: COL6A2; 21q22.3 Myopathy + Cardiomyopathy: DPM3; 1q12 Contractures: TOR1AIP1; 1q25 Epilepsy: DPM2; 9q34 Infant stiffness: CRYAB; 11q22 Lipodystrophy: PTRF; 17q21 MR & Eye: GMPPB; 3p21 Ophthalmoplegia: MYH2; 17p13 Triangular tongue: LIMS2; 2q14

Limb girdle dystrophies:X-linkedBarth: G4.5 (Tafazzins); Xp28Becker: Dystrophin; Xp21Duchenne: Dystrophin; Xp21Emery-Dreifuss Emerin; Xq28 FHL1: Xq26 Manifesting carriers Dystrophinopathy MyotubularinMcLeod Syndrome: XK; Xp21.1;Vacuolar Danon's disease: LAMP-2; Xq24 Excess Autophagy: VMA21; Xq28 MR & Cardiac: LAMP-2; Xq24Other inherited myopathy syndromes-Dystroglycan disordersAPECED: AIRE; 21q22 Autophagy Excessive: VMA21; Xq28 Multisystem: CLN3; 16p11 OtherBarnes's myopathy Cardiac + Myopathy Cardiomyopathy-associated myopathy Cardiomyopathy(? LGMD1B) LGMD 1E: Desmin; 2q35Congenital Myopathies:Late-onset Muscular dystrophies(MDDG)Cytoplasmic body myopathiesDistal myopathies Ehlers-Danlos TNXB; 6p21 FKBP14; 7p14Familial myasthenia gravisFSH dystrophy FSHD1: D4Z4 deletion; 4q35 FSHD2: SMCHD1; 18p11 & 4q35 alleleGlycogenosesGlycosylationHyaline body: MYH7; 14q11 Inclusion Body (IBM) Distal + Resp: TTN; 2q31; Dominant IBM1: Desmin; 2q35; Dominant IBM2: GNE; 9p12; Recessive IBM3: MyHC-IIa; 17p13; Dominant IBM4: 7q22; Dominant LGMD 1D: DNAJB6; 7q36; Dominant IBM + Paget HMERF: Titin; 2q24; DominantLipidMitochondrialMyotonic dystrophyOphthalmoplegia: MYH2; 17p13; RecessiveOther dystrophiesProtein surplusReducing bodyRespiratory failureScapuloperoneal syndromesSkeletal+ Myopathy Bone fragility: MTAP; 9p21 Paget(VCP; HNRNPA2B1; HNRNPA1) Dysplasia Diaphyseal: TGFB1; 19q13 Epiphyseal(COL9A3; COL9A2; COMP)Spheroid body(Myotilin)Tubular aggregatesTubular arraysLGMD: General features

Muscle proteinsConnective tissueDystrophin & associated proteinsIntermediate filamentsNeuromuscular junctionNuclear envelopeStructural & Contractile

LGMD: General featuresInheritanceMyopathy:General featuresPresenting featuresPrevalenceProteins: Subcellular locationSarcoglycansWeaknessFrom Bramwell:Atlas of Clinical MedicineMD: Toe walking

Myopathies:General features Inheritance LGMD1:Dominant LGMD2:Recessive X-linked Other Weakness Typical Slowly progressive Symmetric Proximal Severe:Duchenne; Sarcoglycanopathy (LGMD2C,2D,2E,2F);LGMD 2A(Some patients) Mild:Becker;LGMD 1G,2A,2B,2G Distinctive, selective patterns Extraocular Arm Quadriceps Paraspinous:2B Distal: LGMD1C;2B Asymmetric Scapular Other distinctive features: Dystrophies may also present with Myoglobinuria Pain Myotonia Systemic signs Contractures Muscle hypertrophy Cardiomyopathy High serum CK: EspeciallyDMD, Sarcoglycanopthies,LGMD 2B Rippling muscles: LGMD1C Vacuoles Subcellular localization of myopathy-related proteins Nucleus Emerin:X-linked Emery-Dreifuss Lamin A/C:Autosomal dominant Emery-Dreifuss Nesprin (SYNE)1&2: Autosomal dominant Emery-Dreifuss Myotubularin:Myotubular myopathy PABP2:Oculopharyngeal muscular dystrophy VCP:IBMPFD Matrin-3:MPD2 TNPO3:LGMD 1F Cytosol Calpain-3:LGMD 2A Tafazzins:Barth DMPK:Myotonic dystrophy Zinc finger protein 9 (ZNF9):Proximal Myotonic Myopathy (PROMM; DM2) TRIM32:LGMD 2H Golgi FKRP:LGMD2I;Congenital Muscular Dystrophy (MDC1C) TRAPPC11:Myopathy with Movement Disorder & Intellectual Disability Myofibrillar Cytoskeleton Dystrophin:Duchenne;Becker Telethonin:LGMD 2G Nebulin:Rod myopathy(NEM2) Plectin:Congenital Muscular Dystrophy + Junctional Epidermolysis Bullosa Titin:LGMD 2J Contraction-related cytoskeleton -Actin (ACTA1):Rod myopathy -Tropomyosin 3 (TPM3):Rod myopathy(NEM1) Troponin T1:Rod myopathy Myosin:Acute quadriplegic myopathies;Hypertrophic cardiomyopathies;Hearing loss Sarcolemma Sarcoglycans :LGMD 2D(Adhalin deficiency) :LGMD 2E :LGMD 2C :LGMD 2F : Myoclonus-Dystonia syndrome (Dominant; Maternal imprinting)26 Caveolin-3:LGMD 1C;Hyper-CKemia;Rippling muscles 7-Integrin:Congenital myopathy Dysferlin:LGMD 2B; Miyoshi distal myopathy Acetylcholine receptor subunits:Hereditary myasthenia gravis Ion channels Chloride Channel (CLCN1):Myotonia congenita;Myotonia levior Sodium Channel - subunit (SCN4A) Paramyotonia Acetazolamide-responsive Myotonia Congenita Hyperkalemic periodic paralysis Hypokalemic periodic paralysis Myotonia Fluctuans Myotonia Permanens Potassium channels KCNE3:Hyperkalemic periodic paralysis KCNJ2 (Kir2.1):Andersen Syndrome Sarcoplasmic reticulum Ryanodine receptor:Central core Calcium ATPase (ATP2A1):Brody's syndrome Calcium Channel, 1 subunit (Dihydropyridine Receptor) (CACNA1S) Hypokalemic periodic paralysis Malignant hyperthermia Extracellular matrix Laminin 2:Congenital muscular dystrophy Collagen VI:Bethlem myopathy;Ullrich congenital muscular dystrophy Laminin 1: Reduced around muscle fibers inBethlem myopathy Collagen IX3:Epiphyseal dysplasia + Myopathy(EDM3): Acetylcholinesterase, Collagen tail:Hereditary myasthenia gravis ? Fukutin:Congenital muscular dystrophy Perlecan:Schwartz-Jampel Syndrome (Chondrodystrophic myotonia) -dystroglycan33 Disorders Amnormalities may involveDAG1mutations or abnormal glycosylation due to other mutations Also see: Metabolic disorders Lipid myopathies Glycogen disorders Mitochondrial disorders3. LGMD 1H Prevalence of recessive muscular dystrophies LGMD2D: Most prevalent in US, Europe & Brazil LGMD2C: Most prevalent in Tunisia Brazil has relatively high frequencies of LGMD2E(8%) &2F(6%) LGMD2A: Common on Runion Island, Guipuzcoa, Northern Indiana, Russia Dystrophin-associated glycoprotein(DAG; Sarcoglycan) mutations: Typical features Mutations in one DAG often also result in reduced amounts of the others in muscle Severe weakness Very high serum CK Complexes of DAGs are different inextrasynaptic musclethan atneuromuscular junctions

LGMD2: Recessive Inheritance General Carriers: Have increased Serum CK in < 5% of cases Geographic foci Brazil:LGD 2G Manitoba Hutterites of Canada:LGD 2H Denmark & England:LGD 2I Finland:LGD 2J French-Canadian:LGD 2L

LGMD 2ACalpain-3 (p94 protein); Chromosome 15q15.1; Recessive

GeneticsCalpain-3 proteinClinicalLaboratoryFrom: C Angelini MD

Genotype & Phenotype Mutations: > 150 identified7 Mutation patterns Private variant mutations in 70% Recurrent mutations: Founder effect 1.5x more frequent than than recurrent Single base pair: 60% to 70% Missense: Most, ~80% Stop codons: Few Splicing defects: ~15% Small insertions or deletions: 30% to 40%; Most cause frameshift & premature stop codon 1 Large genomic deletion: 2 to unequal recombination between two intragenic Alu elements Overall ~45% of mutations are truncating Location: Present through most of gene Excess of mutations: Exon 21 Excess of point mutations: Exons 5, 11 (11 amino acid span with multiple CpG sites) & 21 Excess of deletions/insertions: Exons 15, 17, & 22 R490Q mutation Located in catalytic site Protein is present by Western blot LGMD phenotype: Variable severity of weakness G222R mutation Mutations: Compound heterozygote for R110X & G222R Loss of function: Size & Abundance normal Early onset weakness Disease foci Multiple mutations in some foci: Runion island 60% have IVS6-1GA Amish & Basque populations Digenic inheritance: ?? Single mutation Guipuzcoa (Basque Country, Spain): Exon 22, 2362AG[rarr]TCATCT in 76% US Northern Indiana Amish: R769Q in 100% Russia, Eastern Mediterrananean & North Italy: 550delA; Mutation frequency 1/150 Venetian lagoon: R490Q Other foci: Brazil, Turkey, Japan Mutation Databases HGMD Leiden:Sequence variants Calpain-3 (p94) protein Function Ca++activated non-lysosomal cysteine thiol-protease Cleaves proteins into short polypeptides, not single amino acids Activity may not be Ca++dependent Use cysteine as active site residue Limited proteolytic cleavage of substrate Can bind & cleave titin Role in cytoskeletal remodeling Mutations: Reduced affinity of calpain-3 for titin Localization Expressed prominantly in skeletal muscle: N2-line region Associates with C-terminus oftitin(connectin) in muscle Subcellular: Nucleus Cytosol; Not membrane related Halflife Short (< 10 minutes) Rapid turnover related to insertion sequences (IS) not present in other calpains Clinical correlations Severe phenotype Homozygous null mutations: Often but not always NS1 domain mutations; S86F Least severe phenotype: Homozygous missense mutations S86F heterozygotes: Mildly high serum CK; Normal strength Disease mutations: Effects on calpain function vary, may be selectve for Proteolytic activity vs fodrin substrate: Reduced Autolysis capacity: Reduced Titinbinding: Reduced LGD 2A: Clinical features21LGD 2A: Erb phenotype

From: C Angelini

Disease patterns: Various phenotypes General pattern:Scapula, pelvic girdle & trunk weakness with normal face Differential diagnosis:FSH;LGMD 2I HyperCKemia, asymptomatic (14%): Male > Female 3:1 Limb girdle types (76%) Early onset: < 12 year Group with most homogeneous progression Contractures more common Null mutations common Leyden-Mobius type Onset 13 to 29 years Weakness: Pelvic-femoral girdle Late onset Age: > 30 years Weakness: Pelvic girdle Erb dystrophy type (10%): Scapular-humeral phenotype Onset age: 16 to 37 years Weakness early in shoulder girdle Male = Female Calpain-3 in muscle: Often normal Miyoshi muscular dystrophy phenotype Severity of weakness Heterogeneous: Mild to Early onset severe Mild phenotype in majority Male = Female Onset Early motor milestones: Most normal; Toe walking common Range: 2 to 45 years; Median = 14 to 20 years; 71% between 6 to 18 years Weakness: Proximal legs; Rectus abdominus No clear sex differences; ? Females slightly younger than males Weakness General Symmetrical Proximal + Milder Distal Legs > Arms at onset: Most patients Progressive Rectus abdominus Peri-Scapular Latissimus dorsi; Serratus magnus Scapular winging (83%): Symmetric Legs: Gluteus maximus; Adductors; Knee flexion; Ankle dorsiflexion Arms: Shoulder adduction; Elbow flexion; Wrist extension Respiratory Vital capacity: Declines over time; Rarely < 80% No nocturnal hypoventilation Quadriceps: May be selectively spared Normal: Face; Ocular & Bulbar Gait Inability to walk on heels Lumbar lordosis Loss of walking: Mean late 2nd or 3rd decade Muscle size Atrophy Early in posterior compartments of limbs Different from Quadriceps wasting in Sarcoglycanopathies May be apparent on CT Most affected: Gluteus maximus & Thigh adductors Pelvic; Shoulder; Proximal limbs; Trunk; May bescapuloperoneal Hypertrophy Some patients: Especially in Brazil Calf most common: Not prominent Contractures Onset: May occur early in disease course Calf: Toe walking may be presenting sign Other: Elbow, Wrist & Finger flexion Common late in disease progression: Rigid spine May be severe & require surgery CNS Normal, or Mild mental retardation: Average IQ = 77 Cardiac: No involvement Some patients are asymptomatic withelevated serum CK levels Progression Slow: Earlier onset more rapid Loss of walking 10 to 30 years after onset 50% in 3rd decade Most by age 40 years Many patients can still stand, even when in wheelchair Syndrome variation Intrafamilial Similar onset age & severity in some families with null mutations Onset at 15 years Variation in others with 2 Missense mutations or Compound heterozygotes for missense & null mutation Onset 2.5 to 45 years Interfamilial: Prominent LGD 2A: Lab features Serum CK: Normal to 80 times normal; 190 to 11,000 MRI Thigh: Varies with degree of function Prominent in most patients: Posterior Early & Good function: Adductors; Semimembranosus Restricted ambulation Diffuse involvement: Posterolateral thigh & Vastus intermedius Sparing: Vastus lateralis, Sartorius & Gracilis Calf Involvement: Soleus; Gastrocnemius, Medial head Relative sparing: Gastrocnemius, Lateral head Muscle Biopsy Myopathic Muscle fibers Necrosis & Regeneration Active myopathic changes Eosinophils in some assciated cellularity Myopathic groups: May involve clusters or whole fascicles early in disease34 Size: Variable; Small rounded to Hypertrophic Internal architecture Usually unremarkable Regenerating fibers: Coarse internal architecture Lobulationof Type I fibers: Later in disease course Nuclei: Internal; Apoptosis with altered IB/NF-Bpathway Groups of atrophic (type 2) muscle fibers Endomysial fibrosis: Increased with longer disease course Fiber types Type 2 hypertrophy: Some patients Type I predominance: With increasing weakness Type 2C: Common Inflammation Some biopsies May be perivascular or endomysial Dystrophy-related proteins Calpain-3: Western blot patterns Loss of all calpain-3 bands High specificity for LGMD2A: Frequency 23% May have null or missense mutations Absence or reduction of 60 kDa bands: Highly specific (94%); Sensitive (64%) Absence or reduction of 30 kDa bands: Specific (88%); Sensitive (58%) Increased lower MW 60 kDa region bands: No mutations (92%); Suggests protein degradation artifact Normal full-sized calpain-3 protein Occurs in 23% of patients with 2 calpain-3 mutations Often have loss of autocatalytic function Abnormal Western blot with only 1 calpain-3 mutation: Similar phenotype to patients with 2 mutations found Calpain-3 reduction may occur in other myopathiesDystrophin;LGMD 1C;LGMD 2B (Dysferlin);LGMD 2I(FKRP);LGMD 2J (Titin) Dysferlin: Reduced or absent in some patients; Western blot normal Sarcoglycans & Dystrophin: Normal Ultrastructure: Patchy damage tomyofibrillar Z, I & A bands Diagnosis41 Genetics Difficult due to many different mutations More common in some regions of gene: 87% of mutant alleles exons 1, 4, 5, 8, 10, 11 & 21 Some common mutations: 61% have one of eight mutations Directed mutation analysis: Geographic groups Some patients with only 1 detected mutation have typical LGD 2A phenotype Western blot Calpain-3 enzyme activity: Reduced Mouse model: Calpain-3 knockout42 Misaligned A-bands Abnormal sarcomere formation

LGMD 2BDysferlin; Chromosome 2p13.2; Recessive

ProteinClinicalLaboratoryPathologyVariant syndromesMouse modelsFrom: C Angelini

Gene 55 exons Allelic with Miyoshi distal myopathy(MM) Distal myopathy with anterior tibialis onset(DMAT) Variant syndromes Locus near, but different from,Welander distal myopathy Gene mutations25 > 450 different mutations described 18% of patients with dysferlin deficiency have only 1 (heterozygous) mutation identified on 1 allele Mutation types Types: Missense (26% to 46%); Nonsense (18% to 26%); Deletions; Insertions; Intron; Splice site Distributed over entire coding sequence + Introns: Most mutations private variants Most introduce stop codons or premature truncations of the dysferlin protein Splice site (in-frame) mutation (A3443-33G)53 May allow some residual dysferlin protein production Clinical phenotype: Milder Mutation locations in gene: Widely dispersed over coding sequence Variations in phenotype not well explained by mutation type Geographic distribution Mutations present at low frequency in many populations: Typically 1% of recessive LGMD 33% of distal myopathies Common in Libyan Jews: 1624delG; Carrier frequency up to 10% Japanese G2997T (Trp999Cys); G3370T: Mild disease phenotype; Later onset G3510A: More severe disease; Earlier onset; High CK Other common mutations: 3746delG; 4870delT 3373delG: Japanese Miyoshi Sueca, Spain: Arg1905X50 External links Mutation Databases:Leiden;Sequence variants Diagnostic tool:Jain Foundation Protein: Dysferlin Tissues: Skeletal muscle > Heart; Ubiquitously expressed at low levels Size 230 kDa + Multiple lower weight bands 55 exons Subcellular localization Plasma membrane: Present at periphery of muscle fibers T-tubules Cytoplasmic vesicles: Trans-Golgi network secretory vesicles Homology to Nematode spermatogenesis factor (fer-1): Required for cell fusion Myoferlin: Plasma membrane & Nuclear envelope Otoferlin Domains Transmembrane: Short, C-terminal, hydrophobic C2: 7 domains; Hydrophilic; Bind calcium & cellular membranes Most of dysferlin protein intracellular Extracellular domain: Small Interactions: Binds to62 Caveolin-3 AHNAK Interaction mediated by calpain-3 Levels reduced in dysferlinopathies Annexins A1& A2 S100 Calcium binding protein A10 Calpain 3(CAPN3) -parvin Dihydropyridine receptor(DHPR) Mitsugumin 53 (MG53; TRIM72): May play role in membrane repair Other: Ca++; Lipids Functions Membrane fusion or repair Ca++-mediated muscle membrane Homeostasis processes Signal transduction events Myogenesis Angiogenesis Microtubule dynamics Dysferlin turnover & levels Half-life in membrane: ~ 3 hours Upregulation:LARGE (myd) mouse Dysferlin: LGMD 2B patients Immunohistochemistry (IHC) Sarcolemma: Absent or Reduced Cytoplasm: Reduced or Increased Western blot Absence has more specificity for LGMD 2B than IHC changes Dysferlin may be normal or increased Some mutations produce cytoplasmic aggregates of normal sized dysferlin protein Clinical: Milder LGMD phenotype85

LGMD 2BNo calf hypertrophy

Onset Age Mean 19 to 27 years Range General: 10 to 39 years Congenital& 8th decade onsets reported Heterogeneity in single family may occur Leg weakness Proximal May be associated with period of exercise Weakness Mild Asymmetry: Common Legs Distal: Posterior muscles Especially gastrocnemius Early inability to walk on toes Differential diagnosis:Distal myopathy with anterior leg sparing Proximal Anterior & Posterior muscle groups Especially quadriceps, also psoas Lower limbs involved 9 years before upper limbs Arms Especially biceps Deltoid: Often spared Trunk: Glutei, Erector spinae, Shoulder girdle involved Face: Generally normal Loss of ambulation: > 30 years Respiratory: More with longer disease duration; Overall 50% have VC < 80% Wide inter- and intrafamilial variation Progression: Slow; Most walk until > 33 years, some into 6th decade Calf size Hypertrophy: Some patients Deltoid hypertrophy with biceps atrophy Posterior leg (Calf): May be early in disease course Occasional distal onset patients Subacute, painful enlarged calves early in course60 Cramps & muscle discomfort: Some patients No cardiomyopathy: Clinically preserved; EF generally > 50% Same mutations may also produceMiyoshi distal myopathy ? Modifier genes determine phenotype Laboratory features CK Typical Very high Range: 10x to 72x normal; Up to 27,000 Lowest: Normal Presymptomatic: 343 to 3,000 ? Age-dependent increase EMG: Myopathic Motor units: Small amplitude; Short duration No spontaneous activity Imaging Early involvement on MRI or CT Posterior leg:Gastrocnemius atrophy, especially medial heads; soleus Thigh: Hamstrings Erector spinae Late or minimal involvement: Gracilis; Sartorius; Glutei Muscle

Dysferlin stainingin normal muscle

Pathology: Dystrophic Muscle Necrosis & degeneration of muscle fibers Endomysial connective tissue: Increased in more involved muscles Muscle fibers: Size variation, may appear bimodal; Splitting No vacuoles Inflammation: Some mutations22 Perimysial & perivascular cell infiltrates: Some muscles T-lymphocytes No MHC class I antigen on muscle fibers Complement: Membrane attack complex (but not C3) on muscle fiber surface Amyloid7. Present in muscle in some patients1. Mutation locations: N-terminal or other regions7. Location: Muscle fiber surface; Endomysial connective tissue; Perivascular7. Amyloid may contain dysferlin1. Ultrastructure8. Sarcolemmal defects8. Replacement of membrane by layers of small vesicles234. Dysferlin tissue staining30: Absent or Reduced2. Absent staining more specific for LGMD 2B than reduced, but present, staining2. Staining may be patchy among muscle fibers2. Retained staining may be related to splice site mutations in dysferlin gene2. No correlation between level of staining and clinical severity2. Reduced dysferlin staining: Not specific for dysferlinopathy; 60% with no mutation4. Dysferlin Western blot3. Common & specific change in LGMD 2B: Dysferlin reduced to 0% to 20% of normal3. Absent dysferlin on Western blot: Dysferlin gene mutations very common3. Good correlation on WB between3. Skeletal muscle (234 kDa) &3. Monocytes (doublet 224 to 234 kDa)3. Increased dysferlin expression: Mutatons in exons 36 or 374. Other molecules4. Calpain-3: Reduced especially with C2 domain mutations4. Sarcoglycans&Dystrophin: Present4. Aquaporin-4: Reduced Variant syndromes: Different phenotypes may occur in same family. General1. Late in disease course: Varying weakness phenotypes merge. Distal myopathy:Miyoshi. Distal myopathy: Distal anterior dysferlinopathy (DMAT;DACM)3. Onset: Foot drop; Steppage gait3. Weakness2. Legs1. Anterior: Ankle > Knee1. Distal > Proximal2. Arms: Proximal. Proximal + Distal myopathy4. Onset: Proximal weakness; Calf atrophy4. Weakness: More rapidly progressive4. Muscle pathology: Inflammation more common. Later onset, Proximal, Arms > Legs855. Mutation: Trp999Cys; Homozygous5. Onset2. Age: Mean 38 years; 16 years later than others average2. Arm symptoms5. Weakness: Proximal5. Serum CK: High but lower than average. Pain syndrome6. Onset: Distal leg (calf) painful swelling without weakness or atrophy1. Unilateral or Bilateral6. No weakness or atrophy. Asymptomatic withelevated serum CK levels7. Frequency: 5% of dysferlinopathies7. Mutations: Missense or Stop7. Age: 28 & 50 years7. MRI: Mild gastrocnemius pathology. Congenital onset708. Weakness1. Birth: Legs & Neck flexor1. Walking at 19 to 21 months8. Serum CK: Normal early; High after age 58. MRI: Pathology (STIR) in hamstring & gastrocnemius8. Muscle: Dysferlin absent; -dystroglycan normal8. Mutation: p.Ala927LeufsX21 frameshift. Carriers749. May be symptomatic9. Mutations: G519R; D625Y9. Clinical3. Weakness: Legs; Proximal or Distal; Progressive3. Calf myalgias: 1 patient9. Serum CK: High; 600 to 30009. Muscle5. Myopathy5. Dysferlin expression: Reduced & Patchy Mouse model: SJL. Mutation1. Genomic: 141 bp intronic deletion involving tandem repeat1. Effects of mutation2. Alters 3' splicing site2. Causes deletion of exon 45 in cDNA: 171-bp in-frame deletion1. Protein results3. Deletion of 57 amino acids3. Reduced amount to 15% of normal. Pathology: Myopathy Inflammation Mouse model: A/J. Retrotransposon insertion in intron 4 (5' end) of dysferlin gene. Progressive myopathy: Proximal > Distal. Perivascular inflammation. Dysferlin: Absent by Western blot

LGMD 2C; Severe Childhood Autosomal Recessive (SCARMD) Sarcoglycan; Chromosome 13q12.12; Recessive Sarcoglycan gene Promoters: Muscle, Brain & ? Heart-type Mutations Many mutations disrupt carboxyl-terminus One Japanese patient with 73 base pair deletion Gypsies: C283Y Tunisia & North Africa: del521-T mutation36 Severe phenotype: May have null or missense mutation Databases:Leiden;HGMD Sarcoglycan protein 35 kDDystrophin-associated glycoprotein Peptide mass: 32 kDa Acidic Location: Subsarcolemmal mRNA expressed Strongly: Skeletal & cardiac muscles Moderately: Lungs, Skin, Spinal cord & Olfactory bulb Weakly: Cerebrum & Aorta Sarcoglycan binding: Moderately to -sarcoglycan Homologous sarcoglycan:-sarcoglycan See:Sarcoglycan complex Clinical features Severity Some with Duchenne-like course Others intermediate between Duchenne & Becker phenotype Mild Becker phenotype in occasional family Variable: Interfamilial; Intrafamilial may be homogeneous or heterogeneous Gypsies with C283Y mutation Early Duchenne-like course but longer survival (50%) Becker phenotype (13%) Overall: More severe than North Africans with out of frame del521-T mutation Weakness Onset Mean 5 to 6 years C283Y mutation: < 2 years Proximal > Distal Patchy distribution with some mutations (C283Y) Affected: Glutei, Adductors, Hamstrings, Spinalis, Abdominals, Subscapularis, Soleus Spared:Quadriceps Respiratory: Failure in 3rd decade Muscle hypertrophy: Some patients (C283Y); Calf & Tongue Hearing loss: Neurosensory Cardiac Occasional involvement: Especially late in disease course C283Y mutation: Subclinical; EKG changes 60%; RVH; Diastolic dysfunction Skeletal (C283Y): Lumbar hyperlordosis; Scapular winging Intelligence: Normal Course Loss of ambulation: 10 to 37 years; Mean 16 years No relation between severity of disease & age of onset Death: Common in 2nd decade Laboratory features Serum CK: Very high Muscle pathology Myopathic Inflammation: Occasional Sarcoglycan staining Severe disease: Absent -sarcoglycan Slowly progressive disease: Reduced -sarcoglycan Other sarcoglycans: Levels not related to clinical phenotype : Normal or reduced : Normal or reduced : Variable; May be reduced most or absent Dystrophin: May be normal or reduced

LGMD 2D-Sarcoglycan (Adhalin); Chromosome 17q21.33; Recessive

-Sarcoglycan gene Promoters: 2 Mutations Most mutations are missense in extracellular domain of protein Arg77Cys most common mutation, independent of ethnicity Mutation Databases:HGMD;Leiden -Sarcoglycan protein 50 kDdystrophin-associated glycoprotein Peptide size: 40.4 kDa Homologous sarcoglycan: -sarcoglycan Features distinct from non-homologoussarcoglycans Cadherin-like domain: ? Function by associating with other glycoproteins Calcium-binding pockets Sarcoglycan binding: Moderately to - & - sarcoglycans Location: Expressed only in skeletal & cardiac muscle See:Sarcoglycan complex -Sarcoglycan gene abnormalities May produce absent or reduced level of -Sarcoglycan in muscle Levels of -Sarcoglycan correlate roughly with gene structure Null mutations: Often absent -Sarcoglycan Missense mutations: Reduced -Sarcoglycan Severity of myopathy correlates best with level of -Sarcoglycan in muscle Absent -Sarcoglycan:Duchenne-like phenotype Reduced -Sarcoglycan: Later onset; Milder weakness Other myopathies: -Sarcoglycan may be reduced in other dystrophies Especially othersarcoglycan disorders Reduced -Sarcoglycan in muscle (? gene defect): ? Related to dilated cardiomyopathy Clinical features: Severe or Mild phenotype Onset Variable: 2 to 15 years Earlier onset More rapidly progressive weakness Absent -Sarcoglycan Later onset Ambulation may be preserved Occasional patients with onlyhigh CK, but no weakness Reduced but present -Sarcoglycan Weakness Proximal > Distal Symmetric Quadriceps: Severe phenotype Scapular weakness & winging: Severe phenotype Calf hypertrophy: Some patients Systemic: Rare associatedcardiomyopathy Laboratory features Serum CK: Very high; Often > 5,000 Muscle biopsy Myopathic Fiber size variation Endomysial connective tissue: Increased Degeneration & Regeneration of muscle fibers Myopathic groupingof degeneratiing & regenerating muscle fibers Sarcoglycan staining Absent -sarcoglycan Other sarcoglycans: Reduced or absent Treatment: Prednisone inproves motor function (Anecdotal reports) Heterozygotes (Ile124Thr missense mutation): Some patients have a clinical phenotype38 Myalgias Scapular winging: 60% Calf hypertrophy: 15% Serum CK: Normal Muscle biopsy: Fiber-size variability; Atrophic fibers; Normal -sarcoglycan by IHC

LGMD 2E-Sarcoglycan; Chromosome 4q12; Recessive Epidemiology: Common in Northern & Southern Indiana Amish; Bern, Switzerland -Sarcoglycan gene Promoters: 1 Mutations Missense: Common Common mutation: Ser114Phe Also: Nonsense, Insertion & Deletion Databases:Leiden;HGMD -Sarcoglycan protein 43 kDdystrophin-associated glycoprotein Peptide size: 34.8 kDa Binds to -dystroglycan by extracellular domain Sarcoglycan binding: Strongly to ; Moderately to Location: Subsarcolemmal Expression patterns Muscle: Skeletal & Cardiac Only sarcoglycan expressed outside muscle: Brain; Kidney See:Sarcoglycan complex Clinical features: Severe; Occasional mild phenotype Onset age < 3 years to Teens Teen onset: Similar to "outlier"dystrophinopathy Intrafamilial variability Myopathy Proximal weakness Muscle hypertrophy: Prominent; Tongue Shoulders:Scapular winging; Muscle wasting Progression: Often in wheelchair by 10 to 15 years, usually by 25 years Cardiomyopathy Occasional patients Mutation: 8 bp duplication in exon 3 of 1 allele Laboratory features Serum CK: High; Often > 5,000 Muscle biopsy Myopathic Sarcoglycans: All usually absent or markedly reduced Dystrophin: Often reduced but not absent Cardiac muscle: Sarcoglycans reduced with cardiomyopathy -Sarcoglycan knockout mouse Myopathy with muscle hypertrophy Cardiomyopathy with focal areas of necrosis Reduced Sarcoglycan-sarcospan complex in vascular smooth muscle: Vascular in heart, diaphragm & kidneys

LGMD 2F-Sarcoglycan; Chromosome 5q33.3; Recessive -Sarcoglycan gene Promoters: 3; 1 predominantly in skeletal muscle Mutations FrameshiftPremature truncation of protein: del656C: African-Brazilian ancestry Missense: Glu262Lys (Near cysteine-rich region) NonsensePremature truncation of protein: E93Ter; Arg165Ter; Trp30Ter Databases:HGMD;Leiden Allelic with:Dilated cardiomyopathy 1L(CMD 1L) -Sarcoglycan protein 35 kDdystrophin-associated glycoprotein Basic Location: Subsarcolemmal Sarcoglycan binding: Strongly to - & - sarcoglycans Homologous sarcoglycan:-sarcoglycan See:Sarcoglycan complex Clinical: Severe phenotype with most mutations producing myopathy Onset: 2 to 10 years Weakness: Proximal; Symmetric Other muscle change: Calf hypertrophy; Cramps Progression: Wheelchair 9 to 16 years in most; One patient walking at 19 years Death: 9 to 19 years Intelligence: Normal Cardiac Often Normal Dilated cardiomyopathydescribed: May occur without skeletal myopathy Clinical variant: Mild LGMD phenotype described Laboratory features Serum CK: High; 10x to 50x normal Muscle biopsy Myopathic: Degeneration & regeneration of muscle fibers Immunostaining -Sarcoglycan: Absent Other sarcoglycans: & absent; reduced or absent Dystrophin: Present but reduced Animal model Syrian hamster cardiomyopathy: Deletion in promoter region of -Sarcoglycan gene

LGMD 2GTelethonin (Titin-Cap; TCAP); Chromosome 17q12; Recessive Epidemiology: Brazil (Italian ancestry) & Europe Genetics Point mutations or small deletions Mutations produce stop codons Trp25X; Gln35X; g.637-640del2 Telethonin (Titin-Cap) protein

Telethonin in muscle fibers

Function Substrate of serine kinase domain oftitin Titin phosphorylates C-terminal domain of telethonin Occurs in early differentiating myocytes Tissue localization: Cardiac & skeletal muscle Cellular localization: SarcomericZ-disc Clinical features Onset: Mean age 12.5 years; Range 9 to 15 years Weakness: Arms: Proximal Legs: Proximal &Distal(Foot drop) Face & Neck: Normal Progression: 40% non-ambulatory in 3rd or 4th decade Muscle size Calf hypertrophy 50% Calf atrophy 50% Cramps: Occasional patient Cardiac involvement55% Laboratory Serum CK Increased 3- to 30-fold Lower with greater age Muscle imaging Preservation: Adductor longus Hypertrophy: Sartorius More involvement: Quadriceps; Anterior tibial Muscle pathology Myopathic: Degeneration & Regeneration Rimmed vacuoles: Some patients Lobulated muscle fibers Telethonin absent from muscle Varianttelethoninsyndrome:Dilated cardiomyopathy 1N(DCM 1N) Varianttelethoninsyndrome:Congenital Muscular Dystrophy80 Epidemiology: French male Mutation: Homozygous Gln58X Clinical Motor Milestones: Delayed head control & sitting Weakness Proximal (Psoas; Adductors) > Distal Anterior tibial Neck flexion Course: Minimal progression Gait: Waddling; Falling Muscle size: Glutei wasting; Calf hypertrophy, mild Skeletal Scapular winging Scoliosis Joint laxity: Distal arms Contractures: Ankles Heart: Normal Laboratory Pathology: Muscle Fiber size: Varied Internal nuclei Necrosis & Regeneration: Some clusters Type I fibers: Small Telethonin: Absent -Dystroglycan: Normal Serum CK: 600 to 1300

LGMD 2I (MDDGC5)18Fukutin-related protein gene (FKRP); Chromosome 19q13.32; Recessive Nosology: Muscular dystrophy-Dystroglycanopathy Epidemiology > 40 familes Carrier risk: ~ 1:400 Common in Denmark & parts of England Genetics Point mutations most common: Missense Common mutation in 1 allele (> 90%): Leu276Ileu (C826A) Disease severity correlates with mutation in 2nd allele Leu276Ileu homozygosity correlates with less severe phenotype Allelic with Congenital muscular dystrophy with muscle hypertrophy & Normal CNS (MDC1C) Myopathy with abnormal merosin (Laminin-2) Walker-Warburg syndrome: Homozygous FKRP mutations; Met1Val & Cys318Tyr FKRP protein Ubiquitous Highest levels: Skeletal muscle; Heart; Placenta Subcellular Golgi Skeletal and cardiac muscle Surrounds myonuclei No change in location with disease mutations Absent from the nuclei of interstitial cells Targeted by N-terminus & tm domain Not secreted Glycosyltransferase Colocalizes with -Mannosidase II Associated withdystroglycanprocessing Clinical Onset Age Range 0.5 to 27 years; 61% less than 5 years Birth in patients withCongenital muscular dystrophy syndrome(MDC1C) Weakness: Waddling gait; Difficulty with stairs; Hypotonia Weakness Proximal > Distal Legs & Arms Legs: Thigh adductors; Psoas; Quadriceps Arms:Periscapular; Deltoid; Biceps; Triceps Face: Mild weakness in some older patients Respiratory failure(30%) May occur while patient still ambulant DMD-phenotype: Onset in later teens Severity Variable:DMD-liketo Adult onset myopathy Intrafamilial variability described Asymmetry: Some patients Progression Early onset: Non-ambulant by teens Later onset: Slow; Variable; Some (28%) non-ambulant by 4th to 6th decade Muscle size Wasting: In regions of weakness; Arms > Legs Hypertrophy: Calves 77%; Thighs;Tongue Other occasional muscle features Exertional pain: Early symptom,: Mean 14 years, Range 2 to 45 years Cramps: Limbs & Tongue described Myoglobinuria(25%) Multiple episodes Related to physical activity Can occur at time with mild or no weakness Frequent in patients with homozygote common mutation (Leu276Ileu) Tendon reflexes: Preserved; Knee mildly reduced Intellect: Normal Skeletal Contractures: Often at ankles; More common in non-ambulant patients Scoliosis Cardiomyopathy Common: 30% to 80%; Often seen on echocardiography Type: Dilated Usually mild Left ventricular failure May be isolated feature: Homozygous C826A mutation No relation to skeletal muscle severity Skin: May be soft or hyperextensible Variable severity Severe: Onset < 2 years; Never run; Lose ambulation in teens Milder: Later onset; Cramps; Muscle hypertrophy Consistent phenotype within individual families Laboratory Serum CK: Very high; 1,000 to 8,000 Muscle biopsy Endomysial connective tissue: Mildly increased Muscle fibers Size: Variation Necrosis & Regeneration Type 1 predominance: Some patients Muscle fiber staining -Dystroglycan: Reduced, specially in severe disease Selective loss of higher MW forms Less severe loss than inMDC1C Some patients have normal staining DDx:Reduced -Dystroglycan 2-laminin: Moderate loss in some patients: May be absent on Western blot Normal: Dystrophin, Sarcoglycans & -Dystroglycan Nerve conduction studies: Normal EKG: Normal MRI: Normal CNS or minimal atrophyMyopathy with abnormalmerosin (Laminin-2)4 Fukutin-related protein gene (FKRP); Chromosome 19q13.3; Recessive Genetics: Allelic withLGMD 2I Clinical Onset Usually adult: 11 to 40 years Female preponderance Weakness Cranial: Eye closure; Neck flexion Upper extremity: Proximal; No scapular winging Lower extremity: Especially hamstrings + hip adductor & flexors Vital capacity: Reduced to 30% to 93% of normal Asymmetry: Some Progressive Muscle hypertrophy: Calves; Brachioradialis Cramps: Occasional Skeletal: Lumbar lordosis; No contractures CNS (MRI) & cardiac: Normal Laboratory Serum CK: 1,100 to 3,700 EMG: Myopathic Muscle histology Variation in fiber size Muscle fiber necrosis Muscle merosin Normal immunocytochemistry of muscle section (80 kDa & 300 kDa fragments) Absent on Western blot

LGMD 2J Titin; Chromosome 2q31.2; Recessive Genetics Mutations Homozygous for titin mutations Mutation types 11 bp insertion-deletion (Finnish; FINmaj): Final exon (363) Missense: Leu293,356Pro (French) Genotype-Phenotype corelations Homozygous 11 bp deletion: Severe, Childhood onset French missense mutation: Onset 3rd decade, Proximal Arms Allelic disorders Dominant Finnish distal myopathy Myopathy with Early Respiratory failure Cytoplasmic body myopathy Dilated cardiomyopathy 1G Recessive Multicore disease: Congenital myopathy + Fatal dilated cardiomyopathy(EOMFC) Centronuclear myopathy LGMD 2J ?Hypertrophic myopathy(CMH 9) Titin protein Clinical Usually occurs in families with other members having dominant distal weakness syndrome Onset age Usual: Childhood Range: < 10 years to 3rd decade Weakness Proximal > Distal More severe than in allelic distal myopathy Face: Normal Asymmetric: Some patients Wasting: Anterior tibial Progression Usual: Wheelchair < 30 years, within 20 years of onset Some patients ambulatory at 60 years No cardiomyopathy Laboratory Serum CK: High Muscle biopsy Myopathic No vacuoles Loss ofcalpain-3 Western blot: Severely reduced C-terminal titin fragments Obscurin: Mislocalization Mouse model: Homozygous knockout Severe: Lethal Weakness: Distal > Proximal

LGMD 2M (MDDGC4)59 Fukutin (FCMD; FKTN); Chromosome 9q31.2; Recessive Nosology: Muscular dystrophy-Dystroglycanopathy Epidemiology: 5 families; Portuguese, Turkish, French, Israeli Jewish & Indian Genetics Mutations Types: Stop & Missense 1167dupA; 1363delG; Arg47X; Ala170Glu; Arg246Gly; Arg307Gln; Tyr371Cys Allelic with Fukuyama congenital muscular dystrophy Cardiomyopathy Clinical Onset Age: Less than 6 months Hypotonia Motor delay Deterioration with acute febrile illness Weakness General: Diffuse; Variable severity Distribution: Axial & Proximal > Distal Legs > Arms Face: Mild to Moderate Improves with corticosteroid treatment Many patients ambulant Course: Progressive Muscle size Wasting: Most muscles Hypertrophy: Posterior leg Tongue & other CNS Normal in mildest patients Reduced intelligence: Variable association with degree of weakness Skeletal Spinal rigidity Joint contractures Cardiomyopathy: Some patients Laboratory Serum CK: Very high Muscle biopsy Morphology: Dystrophic; Muscle fiber necrosis Endomysial connective tissue: Increased Glycosylated-dystroglycan: Nearly absent Laminin-2, 1 & 1: Mildly reduced MRI: May show cortical & posterior fossa pathology Vermis hypoplasia Polymicrogyria