Clinical features, gene mutation and genetic counseling in Rett syndrome patients / 中华实用儿科临床杂志

Objective To investigate the mutations in methyl-CpG-binding protein 2 gene (MECP2 gene) from typical sporadic Rett syndrome patients,explore the correlations between their genotype and phenotype,assist in genetic counseling.Methods Genomic DNA was extracted from peripheral blood leukocytes from 2 patients and their parents using standard protocols.Polymerase chain reaction and direct sequencing were performed using specific primers from 4 exons in MECP2 gene.Results No mutations were found in exon 1,2,3.Two different heterozygous missense mutations in exon 4 within MECP2 gene were identified from 2 patients.Their nuclear acid changes were:c.C473T and c.C397T,leading to amino acid change accordingly:p.T158M and p.R133C.There were no same mutations from their parents.Phenotype of patient with c.C397T was milder than patient with c.C473T.Conclusions Most of typical Rett syndrome patients had mutations in MECP2 gene.Gene test should be performed.Their biological parents should be detected accordingly if the patient had positive found to support genetic counseling.

Comparison of Cj1136,Cj1138 and Cj1139 genes among Campylobacter jejuni strains / 中华流行病学杂志

Objective By sequenceing the Cj1136,Cj1138 and Cj1139 gene of Campylobacter jejuni(C. Jejuni) strains associated with Guillain-Barre Syndrome(GBS),features of Cj1136,Cj1138 and Cj1139 gene were studied.Results were compared with the C.jejuni strain NCTC11168, to find the mutations in sequence of C.jejuni which inducing GBS and their polygenetic relationship was analyzed.Methotis Three GBS-associated C.jejuni strains were isolated from stools of GBS patients from Hebei province who had been diagnosed as clinical AMAN pattern and electrophysiological tests were performed.After distilling and sequencing Cj1136,Cj1138 and Cj1139 genes,results were spliced and assembled into a complete sequence by the terminals overlapped with each other.Sequences of Cj1136,Cj1138 and Cj1139 genes were compared with NCTC11168,to find the mutations and gene feature.Results The Cj1136,Cj1138 and Cj1139 gene of the three GBS-associated C.jejuni strains were composed by 1173 base pairs,1170 base pairs,912 base pairs respectively. The alignment with the related sequence of NCTC11168 showed that there were two same mutations in the Cj1138 gene of the three C.jejuni stains.Data from phylogenetic analysis demonstrated that the three C.jejuni strains were genetically closed to NCTC11168,with the biggest phylogenetic distance between the three of them as 2.1%.Conclusion When compared with NCTC11168 the Cj1138 gene of the three GBS-associated C.jejuni strains had the same mutations which might be related to the development of GBS.Relation between the variation and GBS-pathogenesis remained to be confirmed.The mutations found in the three C.jejuni strains established the foundation for exploring the biological characteristics of GBS-associated C.jejuni strains and demonstrated that the GBS-associated C.jejuni strains of Hebei province having its regional features.