Chen Shuang, Yu Yang, Zhang Han, Li Leilei, Jiang Yuting, Liu Ruizhi, Zhang Hongguo
Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, 1 Xinmin Street, Chaoyang District, Changchun, Jilin Province, 130021, China.
Open Med (Wars). 2020 Nov 9;15(1):1123-1127. doi: 10.1515/med-2020-0199. eCollection 2020.
Chromosomal microdeletions and microduplications likely represent the main genetic etiologies for children with developmental delay or intellectual disability. Through prenatal chromosomal microarray analysis, some microdeletions or microduplications can be detected before birth to avoid unnecessary abortions or birth defects. Although some microdeletions or microduplications of chromosome 5 have been reported, numerous microduplications remain undescribed. We describe herein a case of a 30-year-old woman carrying a fetus with a chromosome 5q21.1-q21.3 microduplication. Because noninvasive prenatal testing indicated a fetal chromosome 5 abnormality, the patient underwent amniocentesis at 22 weeks 4 days of gestation. Karyotyping and chromosomal microarray analysis were performed on amniotic fluid cells. Fetal behavioral and structural abnormalities were assessed by color and pulsed Doppler ultrasound. Clinical characteristics of the newborn were assessed during the follow-up. The left lateral ventricle appeared widened on ultrasound, but the infant appeared normal at birth. The 5q21.1-q21.3 microduplication in the fetus was inherited from his mother. There are seven genes in this duplication region, but their main functions are unclear. According to this case report, microduplication in this region could represent a benign mutation. Clinicians should pay attention to the breakpoints and the genes involved when counseling patients with microdeletions and microduplications.
染色体微缺失和微重复可能是发育迟缓或智力残疾儿童的主要遗传病因。通过产前染色体微阵列分析，一些微缺失或微重复可以在出生前被检测到，以避免不必要的流产或出生缺陷。尽管已经报道了一些5号染色体的微缺失或微重复，但仍有许多微重复未被描述。我们在此描述一例30岁女性，其胎儿存在5号染色体q21.1-q21.3微重复。由于无创产前检测提示胎儿5号染色体异常，该患者在妊娠22周4天时接受了羊水穿刺。对羊水细胞进行了核型分析和染色体微阵列分析。通过彩色和脉冲多普勒超声评估胎儿的行为和结构异常。在随访期间评估新生儿的临床特征。超声检查显示左侧脑室增宽，但婴儿出生时外观正常。胎儿的5q21.1-q21.3微重复是从其母亲遗传而来。该重复区域有七个基因，但其主要功能尚不清楚。根据本病例报告，该区域的微重复可能代表一种良性突变。临床医生在为微缺失和微重复患者提供咨询时应注意断点和涉及的基因。
