同卵双胞胎胆道闭锁患儿染色体核型和全外显子组测序分析

目的:以临床表型不同的同卵双胞胎胆道闭锁（BA）患儿为研究对象，分别进行染色体G显带核型分析和全外显子组测序，检测该组双胎儿是否存在染色体核型异常和差异基因型，初步探讨胆道闭锁发生的遗传学背景。方法:采集3对同卵双胞胎BA患儿外周静脉血作为实验样本，分别进行染色体G显带核型分析和全外显子组测序分析。结果:临床表型不同的同卵双胞胎BA患儿，其染色体G带核型分析结果均无异常，为46，XX或46，XY。全外显子组测序结果显示，未检测到该组同卵双胞胎BA患儿的任何差异基因型。结论:同卵双胞胎BA患儿具有不同的临床表型，其染色体G显带核型正常，提示胆道闭锁的发生与染色体异常无关；双胎儿全外显子组测序检测不存在差异基因型，提示胆道闭锁不是单纯的遗传性疾病，可能与遗传表型或外显率以及其他因素等有关。

The study of chromosome and whole exome sequencing of monozygotic twins with biliary atresia

Objective: To analyze the chromosomal karyotypes and whole exome sequencing of monozygotic twins with biliary atresia(BA) discordant for clinical phenotypes, using chromosomal G-banding staining and Illumina sequencing methods. And to investigate the genetic backgrounds of biliary atresia by detecting chromosomal karyotype abnormalities and differential genotypes. Methods: By collecting the peripheral blood samples of three sets of monozygotic twins with BA, chromosome G-banding karyotype staining and whole exome sequencing methods were performed. Results: In our study, there were no abnormal chromosomal G-banding karyotypes detected in monozygotic twins with BA discordant for clinical phenotypes(46, XX or 46, XY). The results of whole exome sequencing also showed that no differential genotypes were detected in our study. Conclusion: The chromosomal G-banding karyotype of monozygotic twins with BA discordant for clinical phenotypes appers normal, suggesting that the occurrence of biliary atresia may not be related to the chromosomal aberrations; there is no differential genotype of the whole exome sequencing between monozygotic twins, which indicates that BA may not be a type of pure genetic disease, and genetic phenotype, penetrance and other factors may contribute to the occurrence of BA.