Maternal uniparental disomy of chromosome 13 is an uniparental disomy of maternal origin that most likely do not have any phenotypic expression except from cases of homozygosity for a recessive disease mutation for which only mother is a carrier. The disease is maternal uniparental disomy of chromosome 13 (MONDO_0019994, a Monarch Disease Ontology term). Also known as: UPD(13)mat, maternal uniparental disomy of chromosome type 13.