Genetic Medical Center, Women and Children's Hospital of Linyi City, Liyin, China.
Medicine (Baltimore). 2024 Jun 7;103(23):e38461. doi: 10.1097/MD.0000000000038461.
With advances in prenatal diagnostic techniques, chromosomal microdeletions and microduplications have become the focus of prenatal diagnosis. 7q partial monosomy or trisomy due to a deletion or duplication of the 7q end is relatively rare and usually originates from parents carrying a balanced translocation.
Noninvasive prenatal screening (NIPT) showed a fetus with partial deletion and duplication of chromosome 7q. It was not possible to determine whether the fetus was normal.
Conventional chromosome G-banding and chromosome microarray analysis (CMA) were performed on fetal amniotic fluid samples and parental peripheral blood samples.
The pregnant women were given detailed genetic counseling by clinicians.
The fetal karyotype was 46, XY on conventional G-banding analysis. The CMA test results showed a deletion of approximately 7.8 Mb in the 7q36.1q36.3 region and a duplication of 6.6Mb in the 7q35q36.1 region. The parents' karyotype analysis and CMA results were normal, indicating a new mutation.
CMA molecular diagnostic analysis can effectively detect chromosomal microdeletions or microduplications, clarify the relationship between fetal genotype and clinical phenotype, and provide a reference for prenatal diagnosis of chromosomal microdeletion-duplication syndrome.
随着产前诊断技术的进步，染色体微缺失和微重复已成为产前诊断的焦点。由于 7q 端的缺失或重复而导致的 7q 部分单体或三体相对较少，且通常源自携带平衡易位的父母。
胎儿经无创产前筛查（NIPT）显示存在 7q 染色体部分缺失和重复，无法确定胎儿是否正常。
对胎儿羊水样本和父母外周血样本进行了常规染色体 G 带和染色体微阵列分析（CMA）。
临床医生对孕妇进行了详细的遗传咨询。
常规 G 带分析显示胎儿核型为 46,XY。CMA 检测结果显示 7q36.1q36.3 区域缺失约 7.8Mb，7q35q36.1 区域重复 6.6Mb。父母的核型分析和 CMA 结果均正常，提示为新发突变。
CMA 分子诊断分析可有效检测染色体微缺失或微重复，阐明胎儿基因型与临床表型的关系，为染色体微缺失-重复综合征的产前诊断提供参考。
