Monarch Disease Ontology term MONDO_0023419 (hyperprolinemia) is when there isan excess of a particular protein building block (amino acid), called proline, in the blood. This condition generally occurs when proline is not broken down properly by the body. There are two inherited forms:hyperprolinemia type1 and hyperprolinemia type 2. People with hyperprolinemia type I often do not show any symptoms, although they have proline levels in their blood between 3 and 10 times the normal level. Less commonly, affected individuals can experience seizures, intellectual disability, or other neurological or psychiatric problems. Hyperprolinemia is caused by mutations in the PRODH gene and is inherited in an autosomal recessive pattern.