OBSOLETE: Uniparental disomy of chromosome 13

Uniparental disomy of chromosome 13 (UPD 13) is a rare genetic condition in which a person inherits both copies of chromosome 13 from one parent instead of receiving one copy from each parent. This entry is labeled as 'OBSOLETE' in the Orphanet classification, meaning it may have been reclassified or merged with other diagnostic categories. However, the condition itself remains a recognized genetic phenomenon. Normally, we inherit one copy of each chromosome from our mother and one from our father. In uniparental disomy, both copies come from the same parent — either both from the mother (maternal UPD) or both from the father (paternal UPD). When this happens with chromosome 13, it can cause health problems in several ways. If a parent carries a recessive disease gene on chromosome 13, the child may end up with two copies of that faulty gene, leading to a recessive genetic disorder. Additionally, there may be effects related to genomic imprinting, where certain genes behave differently depending on which parent they came from. The symptoms of UPD 13 can vary widely depending on whether the disomy is maternal or paternal, and whether there are regions of the chromosome where both copies are identical (called isodisomy) versus different (heterodisomy). Some individuals may show growth problems, developmental delays, or features that overlap with other chromosome 13-related conditions. There is no specific cure for UPD 13; treatment focuses on managing individual symptoms and associated conditions.

Bring these to your next appointment

• Q1.Is the uniparental disomy in my child maternal or paternal, and does that matter for prognosis?,Are there regions of isodisomy that could unmask a recessive genetic condition?,What specific developmental screenings should we schedule?,Should other family members be tested for carrier status of recessive conditions on chromosome 13?,What early intervention services do you recommend?,How often should we follow up with a geneticist?,Are there any research studies or registries we should consider joining?

Common questions about OBSOLETE: Uniparental disomy of chromosome 13