Prenatal Diagnosis and Genetic Counseling of a Maternally Inherited Chromosome 15q11.2q13.1 Duplication in a Chinese Family.

ABSTRACT

Background: Maternally inherited chromosomal duplications in the region of 15q11.2q13.1 have been associated with neurodevelopmental disorders and other clinical manifestations. Prenatal diagnosis of such duplications is crucial for providing accurate genetic counseling and guiding clinical management decisions. Objective: This study aims to present the prenatal diagnosis and genetic counseling of a maternally inherited 15q11.2q13.1 duplication. Case Presentation A 38-year-old gravida 1, para 0 woman underwent amniocentesis at 16 weeks of gestation due to advanced maternal age. Karyotype analysis was performed on cultured amniocytes, and chromosomal microarray analysis (CMA) was conducted on uncultured amniocytes. Results: The karyotype analysis of the cultured amniocytes revealed a normal karyotype of 46, XX. CMA identified a 4.21 Mb maternally inherited chromosomal duplication in the region of 15q11.2q13.1 (arr[GRCh37]15q11.2q13.1(23,894,550_28,107,154)x3). Conclusions: Copy number variants (CNVs) and unbalanced chromosomal abnormalities (UBCA) identified in prenatal cases require careful consideration and accurate interpretation to determine their potential harm or harmlessness compared to the norm. The combination of prenatal ultrasound, karyotype analysis, CMA, and genetic counseling proves helpful in the prenatal diagnosis of CNVs and UBCA.