Reproductive Medicine & Prenatal Diagnosis Center, First Hospital of Jilin University, Changchun, China.
Jilin Engineering Research Center for Reproductive Medicine and Genetics, Jilin University, Changchun, China.
J Clin Lab Anal. 2020 Jul;34(7):e23288. doi: 10.1002/jcla.23288. Epub 2020 Mar 17.
Terminal duplication on chromosome 15q is a rare chromosomal variation. Affected individuals show similar features such as growth dysplasia or the development of frontal bossing, body deformities, facial abnormalities, and genitourinary or cardiovascular disorders. However, it is not yet clear whether such 15q repeats lead to identifiable patterns of clinical abnormalities. Therefore, the purpose of this study was to analyze the prenatal diagnostic results and clinical manifestations of a fetus with 15q duplication and to summarize the literature.
The case was a fetus at 28 weeks of gestation. The risk of Down syndrome from second-trimester screening was 1/140. Prenatal ultrasound and amniocentesis were performed, and chromosomal microarray analysis (CMA) was used for genetic analysis.
The fetus had abnormal clinical features, including intracardiac echogenic focus in the left ventricle, an aberrant right subclavian artery, and growth delay. The fetal chromosomal karyotype was 46,XX,15q?,12q?,21pstk+, and CMA revealed a 10.163 Mb duplication at 15q24.3-q25.3. The couple chose to terminate the pregnancy after careful consideration.
The combination and rational application of cytogenetics technology and molecular genetics technology such as CMA will open up the field of clinical application and provide useful genetic counseling for parents of fetuses carrying such chromosomal duplications.
15q 末端重复是一种罕见的染色体变异。受影响的个体表现出相似的特征，如生长发育不良或出现额骨突出、身体畸形、面部异常以及泌尿生殖或心血管疾病。然而，目前尚不清楚这种 15q 重复是否会导致可识别的临床异常模式。因此，本研究的目的是分析 15q 重复胎儿的产前诊断结果和临床表现，并对文献进行总结。
该病例为 28 孕周胎儿。唐氏综合征的二联筛查风险为 1/140。进行了产前超声和羊膜穿刺术，并进行了染色体微阵列分析（CMA）进行遗传分析。
胎儿具有异常的临床特征，包括左心室心内点状强回声、右锁骨下动脉异常和生长迟缓。胎儿染色体核型为 46,XX,15q?,12q?,21pstk+，CMA 显示 15q24.3-q25.3 处存在 10.163Mb 的重复。经过慎重考虑，夫妇选择终止妊娠。
细胞遗传学技术和 CMA 等分子遗传学技术的组合和合理应用将开拓临床应用领域，并为携带此类染色体重复的胎儿的父母提供有用的遗传咨询。
