目的探讨1例性发育异常伴智力低下患者的遗传学原因。方法选取2015年2月于郑州市第一人民医院泌尿外科及河南省人民医院医学遗传研究所进行治疗、遗传咨询的性发育异常伴智力低下患者1例。取患者及其父母静脉血,采用常规G显带核型分析确定染色体核型;提取基因组DNA,采用微阵列比较基因组杂交(aCGH)技术对DNA进行扫描和分析,筛选染色体非整倍体性改变及200 kb以上的基因拷贝数变异(CNVs),检索UCSC、DGV、DECIPHER、ISCA及在线孟德尔人类遗传学数据库(OMIM)等数据库进行比对及致病性鉴定。结果患者父母染色体核型及aCGH技术扫描结果均正常。患者染色体核型为46XX,der(6)?dup(6)(p21.3p21.1);aCGH技术扫描结果发现6号染色体短臂存在1个重复的CNVs,位于6p21.32-p21.1(hg19:32261671-43333192),片段大小为11.07 Mb,区内约有180个基因,其中OMIM中23个。结论 6p21.32-p21.1区域染色体重复可能为该例性发育异常伴智力低下患者的主要致病原因;G显带联合aCGH技术可对染色体微变异进行精确定位,有助于为临床诊疗提供准确的遗传学依据。
Objective To identify the genetic causes of one patient with disorders of sexual development combined with mental retardation. Methods One patient with disorders of sexual development combined with mental retardation,who received treatment and genetic counseling in Department of Urology of Zhengzhou First People′s Hospital and Research Institute of Medical Genetics of Henan Provincial People′s Hospital in February 2015,were selected. Venous blood of the patient and her parents was taken,conventional G - banding was applied to determine the chromosome karyotype;genome DNA was extracted,array comparative genomic hybridization(aCGH)was used for scanning and analyzing,changes of aneuploidy of chromosome and gene copy number variations( CNVs)that over 200 kb were screened,UCSC,DGV,DECIPHER,ISCA and Online Mendelian Inheritance In Man(OMIM)were retrieved to compare and identify pathogenicity. Results Both the karyotype and scanning results of aCGH of the patient′ s parents were normal. The karyotype of the patient was 46XX, der ( 6 )? dup ( 6 ) (p21. 3p21. 1);the scanning results found that there was one duplicated CNVs in the short arm of chromosome 6,at 6p21. 32 -p21. 1(hg19:32261671 - 43333192),the segment size was 11. 07 Mb,and 180 genes were in the regions,of which 23 were in OMIM genes. Conclusion The chromosome duplication at 6p21. 32 - p21. 1 region may be the main cause of the disease of this patient with disorders of sexual development combined with mental retardation;G - banding combined with aCGH technique can make accurate positioning of microvariations of the chromosome,and help provide genetic references for clinical diagnosis and treatment.