Estudo clinico e sequenciamento direto do gene Twist em individuos com sinais sugestivos da sindrome de Saethre-Chotzen
AUTOR(ES)
Sandra Regina Dantas Nascimento
DATA DE PUBLICAÇÃO
2001
RESUMO
Saethre-Chotzensyndrome(acrocephalosyndactyly type 111)is an autosomal dominant craniosynostosis condition, with high penetrance and variable expressivity. Mutations in the Fgfr1-Fgfr3 and Twist genes are known to cause craniosynostosis, the former by constitutive activation and the latter by haploinsufficiency. The Twist gene maps to 7p21 and mutations in the gene have been reported in the SCS form of craniosynostosis. The aims of this study were characterize the dysmorphological variability and mutations in exon 1 of Twist gene using direct sequencing in four Brazilian famílies presenting SCS. Twenty-four patients were included in our study, diagnosed as having features of Saethre-Chotzen syndrome. The phenotypic characteristics of ali patients were inventoried. Also, a DNA test had been performed and their genotype was noted. Facial features, present were facial asymmetry (20/24), brachycephaly (16/24), small ear with prominent crura (15/24), maxillary hypoplasia (13/24), lowset ears (13/24), and ptosis of the eyelids (12/24), lowset frontal hairline (12/24), ocular hypertelorism (11/24). Additional findings included partial hands and feet cutaneous syndactyly (18/24), clinodactyly (13/24), and broad great toes (13/24); in one family was observed total cutaneous syndactyly in feet. Skull X-rays were abnormal in 8 patients in which it was performed;partiaI fusionof 1st and 2ndribs wasdetectedin 2 individuaisand 2 had lumbar spina bifida. Chromossomal analysis on GTG-banding were normal. The analysis was carried out by direct DNA sequencing of PCR amplified products for exon 1 in the proband of each family. No Twist mutations were found. In conclusion, this four SCS famílies may have mutations in other genes of the same developmental pathway. This study reinforces the importance of the dysmorphological evaluation in patients with craniosynostosis, as well as ali their famílies, especially ACS 111,in which inter and intrafamilial variability make the diagnosis more difficult
ASSUNTO(S)
suturas cranianas reação em cadeia de polimerase cranio - anomalias e deformidades genetica humana
