Limb-Girdle Muscular Dystrophy and Distal Myopathy
Gene: DNAJB4
Emerging evidence of 2 different disease mechanisms: monoallelic distal myopathy may be caused by toxic gain of function and biallelic loss of function with variable onset myopathy with respiratory failure. There is more evidence for the biallelic myopathy with 3 families.
PMID: 36512060 - A single family with distal myopathy segregating a heterozygous missense variant (c.270T>A p.F90L). In vitro functional assays suggest a toxic gain of function mechanism of disease for p.F90L. Both Dnajb4F90L knock-in and Dnafjb4 knockout mice developed muscle weakness
PMID: 36264506 - 4 individuals from 3 unrelated families with myopathy with early respiratory failure with homozygous variants (c.856A > T; p.Lys286Ter, c.74G > A; p.Arg25Gln, c.785 T > C; p.Leu262Ser). DNAJB4 knockout mice had muscle weakness and fibre atrophy with prominent diaphragm involvement and kyphosis, muscle and myotubes had myofibrillar disorganization and accumulated Z-disc proteins and protein chaperones.
Sources: LiteratureCreated: 14 Apr 2023, 5:39 a.m.
Mode of inheritance
BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Phenotypes
distal myopathy MONDO:0018949; Myopathy, MONDO:0005336, DNAJB4-related
Publications
4 individuals from 3 unrelated families with bi-allelic LoF/missense variants in this gene, and either childhood/adult onset of muscle weakness and respiratory failure. One had HCM.
Functional studies including mouse model.
Sources: LiteratureCreated: 3 Nov 2022, 4:09 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Myopathy, MONDO:0005336, DNAJB4-related
Publications
4 individuals from 3 unrelated families with bi-allelic LoF/missense variants in this gene, and either childhood/adult onset of muscle weakness and respiratory failure. One had HCM.
Functional studies including mouse model.
Sources: LiteratureCreated: 3 Nov 2022, 3:59 a.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Congenital myopathy 21 with early respiratory failure, MIM# 620326
Gene: dnajb4 has been classified as Green List (High Evidence).
Gene: dnajb4 has been classified as Green List (High Evidence).
gene: DNAJB4 was added gene: DNAJB4 was added to Limb-Girdle Muscular Dystrophy and Distal Myopathy. Sources: Literature Mode of inheritance for gene: DNAJB4 was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal Publications for gene: DNAJB4 were set to 36512060; 36264506 Phenotypes for gene: DNAJB4 were set to distal myopathy MONDO:0018949; Myopathy, MONDO:0005336, DNAJB4-related Review for gene: DNAJB4 was set to GREEN