Song Jieping, Jiang Wei, Zhang Chengcheng, Wang Bo
Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, Hubei, People's Republic of China.
Mol Cytogenet. 2022 Jun 3;15(1):21. doi: 10.1186/s13039-022-00598-x.
Copy number variants (CNVs) are an important source of normal and pathogenic genome variations. Unbalanced chromosome abnormalities (UBCA) are either gains or losses or large genomic regions, but the affected person is not or only minimally clinically affected. CNVs and UBCA identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm.
A 24-year-old, gravida 1, para 0, woman underwent amniocentesis at 17 weeks of gestation because the noninvasive prenatal testing (NIPT) results revealed a 12.4 Mb duplication from 10p11.2 to 10q11.2. GTG-banding karyotype analysis was performed on cultured amniocytes. Chromosomal microarray analysis (CMA) on uncultured amniocytes was performed.
Chromosomal GTG-banding of the cultured amniocytes revealed a karyotype of 46,XX,dup(10)(p11.2q11.2). CMA detected a 12.5-Mb chromosomal duplication in the region of 10p11.23q11.21 (arr[GRCh37] 10p11.23q11.21(30,345,109_42,826,062) × 3).
The present report enlarges the known UBCA region 10p11.22-10q11.22 to 10p11.23-10q11.22. Also it highlights that an integration of prenatal ultrasound, NIPT, karyotype analysis, CMA and genetic counseling is helpful for the prenatal diagnosis of chromosomal deletions/duplications.
拷贝数变异（CNV）是正常和致病基因组变异的重要来源。染色体不平衡异常（UBCA）表现为大片段基因组区域的增加或减少，但患者未出现临床症状或仅有轻微临床症状。产前病例中鉴定出的CNV和UBCA，若为无害或有害的变异，则需要仔细考虑并正确解读。
一名24岁初产妇，孕1产0，在妊娠17周时接受了羊膜穿刺术，因为无创产前检测（NIPT）结果显示存在从10p11.2到10q11.2的12.4 Mb重复。对培养的羊水细胞进行了GTG显带核型分析，并对未培养的羊水细胞进行了染色体微阵列分析（CMA）。
培养的羊水细胞染色体GTG显带显示核型为46,XX,dup(10)(p11.2q11.2)。CMA检测到10p11.23q11.21区域存在12.5 Mb的染色体重复（arr[GRCh37] 10p11.23q11.21(30,345,109_42,826,062) × 3）。
本报告将已知的UBCA区域10p11.22 - 10q11.22扩大到10p11.23 - 10q11.22。同时强调产前超声、NIPT、核型分析、CMA和遗传咨询相结合有助于染色体缺失/重复的产前诊断。
