uniparental disomy

Last reviewed 01/2018

Uniparental disomy occurs when an individual inherits both copies of a chromosome from one parent. For example paternal uniparental disomy of chromosome 15 means that both copies of chromosome 15 are inherited from the father (a cause of Angelman syndrome).

The mechanism for uniparental disomy is thought to be trisomic rescue:

  • a defect in meiosis results in two chromosomes from one parent being carried in the egg or sperm
  • following fertilisation, one of the chromosomes is randomly lost
  • if the two retained chromosomes happen to be those derived from one parent then an individual with uniparental disomy develops