Rhabdomyolysis and Metabolic Myopathy
Gene: DTNAComment on list classification: Exercise intolerance is a prominent feature of the myopathyCreated: 9 Nov 2024, 7:05 a.m. | Last Modified: 9 Nov 2024, 7:05 a.m.
Panel Version: 1.17
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Muscular dystrophy, MONDO:0020121, DTNA-related
12 individuals from 4 unrelated families with 2 different monoallelic DTNA variants in exon 18 and affecting the coiled-coil domain of α-dystrobrevin (DTNA). DTNA encodes α-dystrobrevin, a component of the macromolecular dystrophin-glycoprotein complex (DGC) that binds to dystrophin/utrophin and α-syntrophin. Mice lacking α-dystrobrevin have a muscular dystrophy phenotype.
Clinical features with onset between 1st and 4th decades included: myalgia, muscle cramps associated with physical activity, exercise intolerance, and increased serum CK (11/12). Most patients have mild symptoms, only 3 had mild proximal muscle weakness of the lower limbs, and 1 had episode of rhabdomyolysis @20yrs. Muscle biopsies in 8 individuals showed mild myopathic and/or dystrophic features.
The 2 variants (p.Glu529Lys and p.Gln523_Glu529del) were found by targeted exome sequencing and confirmed by Sanger sequencing. They segregated with the disorder in the families and were absent in gnomAD. Immunofluorescent analysis of patient muscle samples showed decreased DTNA immunoreactivity at the sarcolemma, as well as variably reduced immunoreactivity of several other dystrophin-glycoprotein complex (DGC) proteins, suggesting that the DTNA variants resulted in overall destabilization of the DG complex within skeletal muscle.
Sources: LiteratureCreated: 7 Nov 2024, 2:03 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Myopathy with myalgia, increased serum creatine kinase, and with or without episodic rhabdomyolysis MONDO:0859322
Publications
Mode of pathogenicity
Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments
Gene: dtna has been classified as Green List (High Evidence).
Gene: dtna has been classified as Amber List (Moderate Evidence).
Phenotypes for gene: DTNA were changed from Myopathy with myalgia, increased serum creatine kinase, and with or without episodic rhabdomyolysis MONDO:0859322 to Muscular dystrophy, MONDO:0020121, DTNA-related
Gene: dtna has been classified as Amber List (Moderate Evidence).
gene: DTNA was added gene: DTNA was added to Rhabdomyolysis and Metabolic Myopathy. Sources: Literature Mode of inheritance for gene: DTNA was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: DTNA were set to PMID: 36799992 Phenotypes for gene: DTNA were set to Myopathy with myalgia, increased serum creatine kinase, and with or without episodic rhabdomyolysis MONDO:0859322 Mode of pathogenicity for gene: DTNA was set to Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments Review for gene: DTNA was set to GREEN