RESUMO
Congenital heart disease (CHD) has been reported to occur in 14-70% of individuals with Cornelia de Lange syndrome (CdLS, OMIM 122470) and accounts for significant morbidity and mortality when present. Charts from a cohort of 479 patients with CdLS were reviewed for cardiac evaluations, gene testing and information to determine phenotypic severity. Two hundred fifty-nine individuals had either documented structural defects or minor cardiac findings. The presence of CHD was then quantified as a function of mutation status and severity of CdLS: mild, moderate, or severe. Different types of CHD were also evaluated by mutation status to assess for any genotype-phenotype correlation. NIPBL, SMC1A, and SMC3 mutation-positive patients were equally likely to have CHD, although the number of SMC1A and SMC3 mutation-positive patients were small in comparison. Structural CHDs were more likely to be present in individuals with moderate and severe CdLS than in the mild phenotype. This study evaluates the trends of CHD seen in the CdLS population and correlates these findings with genotype.
Assuntos
Síndrome de Cornélia de Lange/patologia , Estudos de Associação Genética , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/patologia , Proteínas de Ciclo Celular/genética , Proteoglicanas de Sulfatos de Condroitina/genética , Proteínas Cromossômicas não Histona/genética , Síndrome de Cornélia de Lange/genética , Feminino , Genótipo , Cardiopatias Congênitas/diagnóstico , Humanos , Masculino , Mutação , Fenótipo , Proteínas/genética , Índice de Gravidade de DoençaRESUMO
Mutations in the cohesin regulators NIPBL and ESCO2 are causative of the Cornelia de Lange syndrome (CdLS) and Roberts or SC phocomelia syndrome, respectively. Recently, mutations in the cohesin complex structural component SMC1A have been identified in two probands with features of CdLS. Here, we report the identification of a mutation in the gene encoding the complementary subunit of the cohesin heterodimer, SMC3, and 14 additional SMC1A mutations. All mutations are predicted to retain an open reading frame, and no truncating mutations were identified. Structural analysis of the mutant SMC3 and SMC1A proteins indicate that all are likely to produce functional cohesin complexes, but we posit that they may alter their chromosome binding dynamics. Our data indicate that SMC3 and SMC1A mutations (1) contribute to approximately 5% of cases of CdLS, (2) result in a consistently mild phenotype with absence of major structural anomalies typically associated with CdLS, and (3) in some instances, result in a phenotype that approaches that of apparently nonsyndromic mental retardation.