title: BAG3-related myofibrillar myopathy in a Chinese family.
abstract: In contrast to the usual slow disease progression in myofibrillar myopathies, patients with Bag3opathy often have a rapidly progressive and more severe phenotype with a worse prognosis. We describe a Chinese patient, born to non-consanguineous parents, who first presented at age 6 with clumsy walking and difficult climbing staircase. With a history of restrictive lung disease previously diagnosed as asthma, she progressed rapidly with proximal myopathy, rigid spine and bilateral tightening of the Achilles tendons requiring surgical elongation. Hypertrophic cardiomyopathy with restrictive physiology was shown by echocardiogram. Moreover, prolonged QT interval was also noted in the patient. Family history was unremarkable yet her father was incidentally found to have prolonged QT interval. Mutation analysis with genomic DNA of the proband showed heterozygous de novo known mutation c.626C>T (p.Pro209Leu) and a germline variation c.772C>T (p.Arg258Trp) in BAG3. Her father was found to be a carrier of c.772C>T. Muscle biopsy findings were suggestive of myofibrillar myopathy on light microscopy and ultrastructural studies. To our knowledge, this is the first Chinese case of Bag3opathy so far reported.
authors.affiliation: Department of Pathology, Princess Margaret Hospital, Hong Kong, China.
authors.forename: H C
authors.initials: HC
authors.lastname: Lee
authors.forename: S W
authors.initials: SW
authors.lastname: Cherk
authors.forename: S K
authors.initials: SK
authors.lastname: Chan
authors.forename: S
authors.initials: S
authors.lastname: Wong
authors.forename: T W
authors.initials: TW
authors.lastname: Tong
authors.forename: W S
authors.initials: WS
authors.lastname: Ho
authors.forename: A Y
authors.initials: AY
authors.lastname: Chan
authors.forename: K C
authors.initials: KC
authors.lastname: Lee
authors.forename: C M
authors.initials: CM
authors.lastname: Mak
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins; D044466:Asian People; D002648:Child; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D009135:Muscular Diseases / Q000235:genetics* / Q000473:pathology; D009154:Mutation; D009210:Myofibrils / Q000378:metabolism / Q000473:pathology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C414431:BAG3 protein, human