Trisomy rescue mechanism: the case of concomitant mosaic trisomy 14 and maternal uniparental disomy 14 in a 15-year-old girl.

Maternal uniparental disomy of chromosome 14 (upd(14)mat) is responsible for a Prader-Willi-like syndrome with precocious puberty. Although upd(14) is often hypothesized to result from trisomy rescue mechanism, T14 cell lines are usually not found with postnatal cytogenetic investigations. We report the coexistence of both chromosomal abnormalities in a 15-year-old girl.