This enzyme helps to break down the pyrroline-5-carboxylate produced in the previous reaction, converting it to the amino acid glutamate.

The conversion between proline and glutamine, and the reverse reaction controlled by different enzymes, are important factors required to maintain proper metabolism and protein production.

A deficiency of the latter enzyme leads to higher levels of proline and a buildup of the intermediate breakdown product pyrroline-5-carboxylate, causing the signs and symptoms of hyperprolinemia type II.Hyperprolinemia is inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered.

[citation needed] It is difficult to determine the prevalence of hyperprolinemia type I, as many people with the condition are asymptomatic.

This rare form of the disorder may appear benign at times,[2] but often involves seizures, convulsions, and intellectual disability.