Maternal uniparental disomy for chromosome 6 in 2 prenatal cases with IUGR: case report and literature review.

Background: Uniparental disomy (UPD) is a rare genetic condition leading to potential disease risks. Maternal UPD of chromosome 6 upd(6)mat is exceptionally rare, with limited cases reported. This study reported two new cases of upd(6)mat and reviewed the literature of previous cases. Case presentation: Both cases exhibited intrauterine growth restriction (IUGR), and genetic analysis confirmed upd(6)mat in each case. The literature review identified a total of 19 cases. IUGR and preterm labor were the most common two symptoms observed, and additional anomalies and genetic variations were also reported in some cases. Conclusion: upd(6)mat is potentially associatied with IUGR, but the precise genotype–phenotype relationship remains unclear. The cases with upd(6)mat may present clinical features due to imprinting disorders. [ABSTRACT FROM AUTHOR]