ABSTRACT
Abstract Hypertrophic cardiomyopathy (HCM) is an autosomal dominant genetic disease caused by mutations in genes encoding sarcomere proteins. It is the major cause of sudden cardiac death in young high-level athletes. Studies have demonstrated a poorer prognosis when associated with specific mutations. The association between HCM genotype and phenotype has been the subject of several studies since the discovery of the genetic nature of the disease. This study shows the effect of a MYBPC3 compound variant on the phenotypic HCM expression. A family in which a young man had a clinical diagnosis of HCM underwent clinical and genetic investigations. The coding regions of the MYH7, MYBPC3 and TNNT2 genes were sequenced and analyzed. The proband present a malignant manifestation of the disease, and is the only one to express HCM in his family. The genetic analysis through direct sequencing of the three main genes related to this disease identified a compound heterozygous variant (p.E542Q and p.D610H) in MYBPC3. A family analysis indicated that the p.E542Q and p.D610H alleles have paternal and maternal origin, respectively. No family member carrier of one of the variant alleles manifested clinical signs of HCM. We suggest that the MYBPC3-biallelic heterozygous expression of p.E542Q and p.D610H may cause the severe disease phenotype seen in the proband.
Resumo A cardiomiopatia hipertrófica (CMH) é uma doença autossômica dominante causada por mutações em genes que codificam as proteínas dos sarcômeros. É a principal causa de morte súbita cardíaca em atletas jovens de alto nível. Estudos têm demonstrado um pior prognóstico associado a mutações específicas. A associação entre genótipo e fenótipo em CMH tem sido objeto de diversos estudos desde a descoberta da origem genética dessa doença. Este trabalho apresenta o efeito de uma mutação composta em MYBPC3 na expressão fenotípica da CMH. Uma família na qual um jovem tem o diagnóstico clínico de CMH foi submetida à investigação clínica e genética. As regiões codificadoras dos genes MYH7, MYBPC3 e TNNT2 foram sequenciadas e analisadas. O probando apresenta uma manifestação maligna da doença e é o único em sua família a desenvolver CMH. A análise genética pelo sequenciamento direto dos três principais genes relacionados à essa doença identificou uma variante em heterozigose composta (p.E542Q e p.D610H) em MYBPC3. A análise da família mostrou que os alelos p.E542Q e p.D610H tem origem paterna e materna, respectivamente. Nenhum familiar portador de um dos alelos variantes manifestou sinais clínicos de CMH. Sugerimos que a expressão heterozigótica bialélica de p.E542Q e p.D610H pode ser responsável pelo fenótipo severo da doença encontrada no probando.
Subject(s)
Humans , Male , Adolescent , Cardiomyopathy, Hypertrophic/genetics , Carrier Proteins/genetics , Pedigree , Phenotype , Cardiomyopathy, Hypertrophic/diagnostic imaging , DNA Primers , Heterozygote , Mutation/geneticsABSTRACT
Objective To explore the clinical and genetic characteristics of 17 cases with glucose-6-phosphate dehydrogenase(G6PD) deficiency in Guizhou,China.Methods The clinical features of 17 patients with G6PD deficiency were analyzed,DNA samples were obtained from the patients and some mothers,and the exons and flanking intronic sequences of the G6PD gene were analyzed by the polymerase chain reaction and sequencing.Results The cases had diverse phenotypes,these patients had acute haemolytic anaemia triggered by eating broad beans,infections,ingestion of specific drugs or the neonatal period and chronic nonspherocytic haemolytic anaemia.Three cases of the patients had concomitant diseases for α Mediterranean anemia,acute myeloid leukemia M2 type and neonatal anal membrane stenosis,respectively.G1376T,G1388A and A95G were the commonest G6PD variants in patients in Guizhou,China.G1376T,G1388A and A95G mutations were observed in 82.4％ cases.Two patients had only compound variants(c.1311 C ＞ T,IVS11 nt 93 T ＞ C).One case in the Rongjiang County,Guizhou Province had novel compound variants (c.G1388A,IVS10-10 T ＞ G) in the world.A patient's mother in the Guiyang City,Guizhou Province,China had compound variants (c.1376 G ＞ T,1311 C ＞ T,IVS11 nt 93 T ＞ C) as a carrier.Conclusions G6PD deficiency has a wide range of clinical heterogeneity.A novel G6PD compound variant haplotype c.G1388A,IVS10-10 T ＞ G was first found in the world,and the SNP spectrum of G6PD was enlarged.There may be a G6PD compound variant haplotype c.1376 G ＞ T,1311 C ＞ T,IVS11 nt 93 T ＞ C in Guizhou.