单纯性染色体18p部分三体综合征患儿的产前遗传学诊断和文献回顾

目的探讨单纯性染色体18P部分三体综合征患者的产前诊断特点。方法联合运用传统染色体核型分析和染色体微阵列(chromosome microarray analysis,CMA)基因芯片技术对家系成员行染色体核型分析和基因组拷贝数变异检测。结果胎儿羊水染色体核型结果为46,XY,der(18),父母双方染色体核型均未见异常;胎儿基因芯片检测结果为arrhg19]18p11.31p11.21(3,521,718-15,099,116)×3,即胎儿基因组18号染色体短臂p11.31p11.21区域存在11.58 Mb的片段重复,父母双方基因芯片结果均为阴性,提示该胎儿的18号染色体结构重排为新发生的。结论在一个有不良生育史家系的胎儿中检出一个罕见新发的单纯性染色体18p部分三体变异,这是世界少见的单纯性染色体18p部分三体综合征的产前病例报道。联合运用传统染色体核型分析和C M A基因芯片技术在预防不良产史家系中胎儿出生缺陷的产前诊断中具有重要的临床应用价值。

Prenatal genetic diagnosis in a fetus with isolated partial trisomy 18p syndrome and literature review

Objective To investigate the characteristics of prenatal diagnosis of isolated partial trisomy 18p syndrome.Methods Traditional chromosome karyotype and chromosome microarray analysis (CMA)was used to process karyotyping and genomic copy number variation analysis.Results The result of fetal amniotic fluid chromosome karyotype was 46,XY,der(1 8).Both parents had normal chromosome karyotype with 46,XY and 46,XX,respectively.The fetal CMA test result was arr hg19]18p1 1.31p1 1.21 (3,521,718-15,099,116) × 3.That is to say,there was 11.58 Mb fragment duplication derived from the chromosome 18 short arm p 11.31 p 11.21 region.CMA test results were negative for both parents,suggesting that the chromosome 18 structure variation of the fetus was de novo.Conclusions A rare novel isolated partial trisomy 18p variation was detected in a fetus whose mother with abnormal pregnancy history.This is world's infrequent prenatal case report of isolated partial trisomy 18p syndrome.Combined with traditional chromosome karyotype and CMA,gene chip technology has an important clinical value in the prevention of fetal birth defects of abnormal pregnancy history family in prenatal diagnosis.