title: Cap disease caused by heterozygous deletion of the beta-tropomyosin gene TPM2.
abstract: "Cap myopathy" or "cap disease" is a congenital myopathy characterised by cap-like structures at the periphery of muscle fibres, consisting of disarranged thin filaments with enlarged Z discs. Here we report a deletion in the beta-tropomyosin (TPM2) gene causing cap disease in a 36-year-old male patient with congenital muscle weakness, myopathic facies and respiratory insufficiency. The mutation identified in this patient is an in-frame deletion (c.415_417delGAG) of one codon in exon 4 of TPM2 removing a single glutamate residue (p.Glu139del) from the beta-tropomyosin protein. This is expected to disrupt the seven-amino acid repeat essential for making a coiled coil, and thus to impair tropomyosin-actin interaction. Missense mutations in TPM2 have previously been found to cause rare cases of nemaline myopathy and distal arthrogryposis. This mutation is one not previously described and the first genetic cause identified for cap disease.
authors: The Folkhälsan Institute of Genetics and the Department of Medical Genetics, University of Helsinki, Helsinki, Finland, and Division of Neurology, University Hospital of Antwerp, Antwerpen, Belgium.
authors: Vilma-Lotta
authors: VL
authors: Lehtokari
authors: Chantal
authors: C
authors: Ceuterick-de Groote
authors: Peter
authors: P
authors: de Jonghe
authors: Minttu
authors: M
authors: Marttila
authors: Nigel G
authors: NG
authors: Laing
authors: Katarina
authors: K
authors: Pelin
authors: Carina
authors: C
authors: Wallgren-Pettersson
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D019066:Facies; D017353:Gene Deletion; D005786:Gene Expression Regulation; D006579:Heterozygote; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D018908:Muscle Weakness / Q000473:pathology; D020125:Mutation, Missense / Q000235:genetics*; D020914:Myopathies, Structural, Congenital / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D012131:Respiratory Insufficiency / Q000473:pathology; D014335:Tropomyosin / Q000235:genetics* / Q000378:metabolism
chemical_list: D000199:Actins; C518659:TPM2 protein, human; D014335:Tropomyosin