No evidence for uniparental disomy of the sex chromosomes in idiopathic male infertility

Uniparental disomy (UPD) is a rare genetic aberration characterized by the uni- rather than biparental inheritance of a pair of homologous chromosomes. Among the various adverse clinical effects that UPD can have in humans, abnormalities of the male reproductive system have been described in UPD of the chromosomes 7, 11, 14 and 15, Given the considerable rate of sex chromosomal aneuploidy in human gametes and zygotes, we postulated that paternal uniparental disomy of the sex chromosomes might be a cause of otherwise unexplained male infertility. With a set of highly polymorphic DNA markers the parental origin of the X chromosome in 41 men with severe idiopathic infertility was determined, In all patients the X chromosome was derived from the mother, indicating regular biparental inheritance of the sex chromosomes, We thus obtained no evidence that paternal uniparental disomy of the X and Y chromosomes is a mechanism underlying idiopathic male infertility.