title: Identification of two novel mutations in the ventricular regulatory myosin light chain gene (MYL2) associated with familial and classical forms of hypertrophic cardiomyopathy.
abstract: Five disease genes encoding sarcomeric proteins and associated with familial and classical forms of hypertrophic cardiomyopathy have been determined since 1989. In 1996 two other genes encoding ventricular regulatory and essential myosin light chains were shown to be associated with a particular phenotype of the disease characterized by mid left ventricular obstruction. The aim of the present study was to search for mutations in the ventricular regulatory myosin light chain gene (MYL2), located on chromosome 12q23q24.3, in a panel of 42 probands presenting a classical phenotype of familial hypertrophic cardiomyopathy. Single-strand conformation polymorphism analysis was used to search for mutations in the coding segments of the MYL2 gene, and the abnormal products were sequenced. Two novel missense mutations, Phe18Leu in exon 2 and Arg58Gln in exon 4 were identified in three unrelated families. None of the affected patients had hypertrophy localized only at the level of the papillary muscle with mid left ventricular obstruction. By analysis of genetic recombinations, one of these mutations identified in a large family allowed us to refine the localization of the MYL2 gene on the genetic map, in an interval of 6 cM containing six informative microsatellite markers. In conclusion, we show that mutations in the MYL2 gene may be involved in familial and classical forms of hypertrophic cardiomyopathy, and we provide new tools for the genetic analysis of patients with familial hypertrophic cardiomyopathy.
authors.affiliation: Biochimie B, and IFR de Physiopathologie et de Génétique Cardiovasculaire, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: J
authors.initials: J
authors.lastname: Flavigny
authors.forename: P
authors.initials: P
authors.lastname: Richard
authors.forename: R
authors.initials: R
authors.lastname: Isnard
authors.forename: L
authors.initials: L
authors.lastname: Carrier
authors.forename: P
authors.initials: P
authors.lastname: Charron
authors.forename: G
authors.initials: G
authors.lastname: Bonne
authors.forename: J F
authors.initials: JF
authors.lastname: Forissier
authors.forename: M
authors.initials: M
authors.lastname: Desnos
authors.forename: O
authors.initials: O
authors.lastname: Dubourg
authors.forename: M
authors.initials: M
authors.lastname: Komajda
authors.forename: K
authors.initials: K
authors.lastname: Schwartz
authors.forename: B
authors.initials: B
authors.lastname: Hainque
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D024722:Cardiac Myosins; D002312:Cardiomyopathy, Hypertrophic / Q000235:genetics* / Q000503:physiopathology; D002648:Child; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D004247:DNA / Q000097:blood; D004252:DNA Mutational Analysis; D005260:Female; D005796:Genes / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008297:Male; D008875:Middle Aged; D018994:Myosin Light Chains / Q000235:genetics*; D010375:Pedigree; D017354:Point Mutation / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D018807:Polymorphism, Single-Stranded Conformational; D016415:Sequence Alignment
chemical_list: D018994:Myosin Light Chains; C107184:myosin light chain 2; D004247:DNA; D024722:Cardiac Myosins