Abstract
Objective: The short arm of chromosome 16 consists of several copy
number variants (CNV) that are crucial in neurodevelopmental disorders;
however, incomplete penetrance and diverse phenotypes after birth
aggravate the difficulty of prenatal genetic counseling. Design: Case
series. Setting: This study uses data from National Taiwan University
Hospital. Sample: We screened 15,051 pregnant women who underwent
prenatal chromosomal microarray analysis between July 2012 and December
2017. Methods: Patients with positive array results were divided into
four subgroups based on the type of mutation identified on screening
(16p13.3, 16p13.11, 16p12.2, and 16p11.2), and the maternal
characteristics, prenatal examinations, and postnatal outcomes of
different cases were reviewed. Main outcome measured: Postnatal
prognosis. Results: Chromosome 16 CNVs were identified in 35 fetuses,
including four with 16p13.3 CNVs, 22 with 16p13.11 CNVs, two with
16p12.2 microdeletions, and seven with 16p11.2 CNVs. Of the 35 fetuses,
17 delivered without early childhood neurodevelopmental disorders, three
developed neurodevelopmental disorders during childhood, and 11 were
terminated. Conclusion: Incomplete penetrance and variable expressivity
make prenatal counseling challenging. We report a few cases of de novo
16p CNVs without further neurodevelopmental disorders.