一个16p11.2微缺失综合征家系的产前诊断及遗传学分析

Prenatal diagnosis and molecular genetic analysis of one family with 16p11.2 microdeletion syndrome

目的探讨一个16p11.2微缺失综合征家系基因型与表型的关系,为临床遗传咨询和产前诊断提供依据。方法分别对孕妇夫妻、胎儿、患儿进行染色体核型分析及750K SNP-Array芯片检测。结果染色体核型分析未见异常;基因芯片检测发现孕妇及胎儿在16p11.2区段存在761.4 kb片段的缺失,患儿在16p11.2区段存在610.0 kb片段的缺失,其丈夫芯片结果未见异常。结论传统的细胞遗传学方法不能诊断16p11.2微缺失综合征,应用750K SNP-Array芯片检测技术可明确断裂点与临床表型的关系,验证了患儿及胎儿的16p11.2缺失片段均来自母亲遗传,为临床遗传咨询提供科学依据。

Objective To investigate the correlation between genotype and clinical manifestations of 16p11.2 microdeletion syndrome,then address the foundation for clinical genetic counseling and prenatal diagnosis.Methods Peripheral blood of the proband,pregnant mother and her husband and amniotic fluid of intrauterine fetus were collected for G-banding karyotype analysis.750K SNP-Array chip detection was utilized to identify the genotypes of family members.Results Karyotype analysis showed no abnormalities.Results of 750K SNP-Array chip showed the mother and fetus have a 761.4 kb deletion in 16p11.2 while the proband has a 610.0 kb deletion in 16p11.2.The father does not carry the microdeletion in the same region.Conclusion Traditional cytogenetics methodologies are not eligible for 16p11.2 microdeletion syndrome diagnosis.Microarray has provided a better approach for identifying the correlation between chromosomal breakpoints and clinical manifestations.Results of our research showed the microdeletions of the proband and fetus were inherited from the mother,and provided evidence for genetic counselling.