Prenatal diagnosis and genetic counseling of a 10p11.23q11.21 duplication associated with normal phenotype

Abstract

Background 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. Case presentation 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. Results 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). Conclusion 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.

Approach and Management of Pregnancies with Risk Identified by Non-Invasive Prenatal Testing

“…However, it is noteworthy that many individuals with this condition do not manifest any evident physical or intellectual disabilities [38]. Genetic counseling is difficult in these situations, where few cases are reported, often with varying results [30,31,39].…”

Prenatal diagnosis and genetic counseling of an inherited unbalanced chromosome abnormalities in a Chinese family

“…Herein the case of a (sub)chromosomal imbalance expressed as duplication of 2q11.1q11.2 is presented, which is per definition an UBCA without obvious clinical consequences for two carriers within the same family. The case highlights that prenatal detection of even large CNVs implicates parental testing to come to a well-funded estimation on the impact of the identified alteration [ 13 , 14 ].…”

Prenatal diagnosis and genetic counseling of a paternally inherited microduplication 18q11.1 to 18q11.2 in a Chinese family

“…Chromosomal microdeletions and microduplications are di cult to detect by conventional cytogenetics. Combination of prenatal ultrasound, karyotype analysis, CMA and genetic counseling is helpful for the prenatal diagnosis of chromosomal microdeletions/microduplications [15] .…”