Both members of a chromosome pair are inherited from one parent rather than one from each parent. Uniparental disomy may be maternal or paternal.

The inheritance of both copies of a single chromosome from one parent (and neither copy from the other).

(UPD) The situation in which both members of a chromosome pair, or parts of a chromosome pair, are inherited from the same parent.

MS = The presence in a cell of two paired chromosomes from the same parent, with no chromosome of that pair from the other parent. This chromosome composition stems from non-disjunction (NONDISJUNCTION, GENETIC) events during MEIOSIS. The disomy may be composed of both homologous chromosomes from one parent (heterodisomy) or a duplicate of one chromosome (isodisomy). UI = D024182

Both members of a chromosome pair are contributed by one parent rather than one from each parent.

A situation in which both members of a chromosome pair are derived from a single parent. In about one-fourth of people with PWS, both chromosome 15s are maternal in origin, and no paternal chromosome 15 is present in the affected individual.

when two copies of a chromosome come from one parent, rather than one copy from the mother, and one copy from the father.

Uniparental disomy (UPD) occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent. UPD can occur as a random event during the formation of egg or sperm cells or may happen in early fetal development.