Premature chromatid separation/mosaic variegated aneuploidy (PCS/MVA) syndrome is a rare genetic disorder. In this case report, we describe the prenatal diagnosis of PCS/MVA syndrome in a 24-year-old, gravida 1, para 1, woman who was referred to us in her second trimester due to fetal growth restriction and extreme microcephaly (-5.0 standard deviations). Amniocentesis and chromosomal analysis confirmed PCS in 80% of cultured fetal cells. PCS findings were positive in 9% of paternal cells and 11% of maternal cells, indicative that both were PCS carriers. Genetic analysis confirmed that the fetus carried a combined heterozygote of maternal G > A point mutation of the promoter area of the BUB1B gene and a paternal Alu sequence insertion between intron 8 and exon 9 of the BUB1B gene. As PCS/MVA syndrome is associated with the development of various malignancies in early life, prenatal diagnosis is important for effective planning of post-natal care.
Keywords: BUB1B gene; case report; microcephaly; premature chromatid separation/mosaic variegated aneuploidy syndrome; prenatal diagnosis.
© 2018 Japan Society of Obstetrics and Gynecology.