{Reference Type}: Case Reports
{Title}: A Fetus with Maternal Uniparental Disomy on Chromosome 20: Case Report with Genetic Analysis and Prenatal Diagnosis.
{Author}: Hu LQ;Deng Z;Li SN;Huang WY;Li L;Xiao GF;Xiao QZ;
{Journal}: Clin Lab
{Volume}: 70
{Issue}: 1
{Year}: 2024 Jan 1
{Factor}: 1.053
{DOI}: 10.7754/Clin.Lab.2023.230647
{Abstract}: <B>BACKGROUND: </B>A fetus with increased copy number of chromosome 20 was identified by NIPT. Here we utilize several genetic tests and analyses to illuminate the etiology of such aneuploidy.<BR><B>METHODS: </B>Amniotic fluid cells were extracted from pregnant woman and sent for karyotype and chromosomal microarray analysis (CMA). Trio pedigree analysis was conducted with Chromosome Analysis Suite and uniparental disomy (UPD)-tool software.<BR><B>RESULTS: </B>CMA identified consistent results, which were 2 regions of homozygosity: arr[GRCh37]20p12.2q11.1 (11265096_26266313)hmz and arr[GRCh37]20q11.21q13.2(29510306_54430467)hmz. The trio pedigree analysis discovered that the fetal chromosome 20 was the entire maternal UPD mosaic with isodisomy and heterodisomy.<BR><B>CONCLUSIONS: </B>When a large segment of chromosome is homozygous, appropriate genetic tests are required to find the potential mechanisms for UPD formation.