UNASSIGNED: Genomic DNA and total mRNA were extracted from peripheral blood cells of GXBB-1 family members. Whole elements of the EXT1gene and its transcript, including exons, introns, exon-intron boundaries, and coding sequence (CDS) clones, were amplified and sequenced. Allele-specific PCR was used to confirm the position and type of mutation.
UNASSIGNED: All patients from the GXBB-1 family harbored the cosegregating heterozygous c.1056+1G>A mutation located in EXT1at an exon-intron boundary. Another three single-nucleotide polymorphisms (SNPs) were also detected in the patients, including IVS2+1G>A in intron 2, c.1844 T>C [p.Pro (CCT) 614Pro (CCC)] in exon 3, and c.2534G>A [p.Glu (GAG) 844Glu (GAA)] in exon 9. The latter two SNPs were synonymous variations.
UNASSIGNED: The heterozygous c.1056+1G>A mutation cosegregated with the phenotype, indicating that it is a pathogenic mutation in the GXBB-1 family. This mutation is reported for the first time in Chinese HMO patients. IVS2+1G>A and c.2534G>A have no relationship with the occurrence of disease. However, c.1844 T>C and c.1056+1G>A are linked, and their interaction needs to be further studied. c.1844T>C is a new SNP that has not been reported internationally.
■从GXBB-1家族成员的外周血细胞中提取基因组DNA和总mRNA。EXT1基因及其转录本的全部元素,包括外显子,内含子,外显子-内含子边界,和编码序列(CDS)克隆,进行了扩增和测序。等位基因特异性PCR用于确认突变的位置和类型。
■来自GXBB-1家族的所有患者都具有位于外显子-内含子边界的EXT1中的杂合c.1056+1G>A突变。在患者中还检测到另外三个单核苷酸多态性(SNP),包括内含子2中的IVS2+1G>A,c.1844T>C[p.外显子3中的Pro(CCT)614Pro(CCC)],c.2534G>A[p。Glu(GAG)844Glu(GAA)]在外显子9。后两个SNP是同义变异。
■杂合c.1056+1G>A突变与表型共分离,表明它是GXBB-1家族中的致病突变。该突变在中国HMO患者中首次报道。IVS2+1G>A和c.2534G>A与疾病的发生没有关系。然而,c.1844T>C和c.1056+1G>A是相连的,它们的相互作用需要进一步研究。c.1844T>C是一种新的SNP,国际上尚未报道。