Introduction Clinical features Demographics Diagnosis Treatment
Prolidase deficiency is sometimes called hyperimidodipeptiduria, imidodipeptidase deficiency or peptidase deficiency. It is a very rare hereditary disorder of collagen metabolism that leads to skin fragility and recurrent ulceration.
Features of prolidase deficiency include:
Prolidase deficiency occurs in approximately 1 in 1 million to 1 in 2 million newborns. It is due to a mutation in theprolidase gene (PEPD). This is located on chromosome 19 and encodes the prolidase enzyme that uses proline (an amino acid) for collagen synthesis.
Prolidase deficiency is inherited in an autosomal recessive pattern. This means that both copies of the gene (inherited from the mother and the father) have the mutation. Carriers of the gene have one copy of the mutation, but usually show no features of the condition.
Diagnosis of prolidase deficiency is usually made during infancy through identification of its typical clinical features and confirmatory investigations. Not all the clinical features are required to make the diagnosis. Investigations may confirm the presence of specific proteins (proline-containing dipeptides) in the urine (which may be called imidodipeptiduria), and low levels of prolidase enzyme in the blood.
Genetic testing may be useful in families known to carry the genetic mutation.
Treatment of prolidase deficiency is aimed at controlling symptoms, particularly the skin ulceration and infections. The response to treatments is variable between patients.
