背景: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重点。由于7q末端的缺失或重复而导致的7q部分单体或三体是相对罕见的,通常源于携带平衡易位的父母。
方法:非侵入性产前筛查(NIPT)显示胎儿染色体7q部分缺失和重复。无法确定胎儿是否正常。
方法:对胎儿羊水样本和父母外周血样本进行常规染色体G显带和染色体微阵列分析(CMA)。
方法:临床医生对孕妇进行了详细的遗传咨询。
结果:常规G带分析胎儿核型为46,XY。CMA测试结果显示7q36.1q36.3区中大约7.8Mb的缺失和7q35q36.1区中6.6Mb的重复。父母的核型分析和CMA结果正常,表明一个新的突变。
结论:CMA分子诊断分析可以有效检测染色体微缺失或微重复,阐明胎儿基因型和临床表型之间的关系,为染色体微缺失重复综合征的产前诊断提供参考。
BACKGROUND: 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.
METHODS: 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.
METHODS: Conventional chromosome G-banding and chromosome microarray analysis (CMA) were performed on fetal amniotic fluid samples and parental peripheral blood samples.
METHODS: The pregnant women were given detailed genetic counseling by clinicians.
RESULTS: 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.
CONCLUSIONS: 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.