A rare congenital disorder of the small peptides metabolism
(imidazoles dipeptides). It is characterized by mild to severe skin lesions affecting
mostly the face, palms, lower legs, and soles. These recalcitrant ulcerations respond
partially to treatment and steroids.
Imidodipeptidase; Peptidase D; Proline Dipeptidase.
Autosomal recessive; the PEPD gene maps to
chromosome 19p13.2; prolidase deficiency seems to be a risk factor for the
development of systemic lupus erythematosus.
The deficiency in exopeptidase prolidase (or
peptidase C) produces massive excretion of imidopeptides (i.e., dipeptides
with a proline or hydroxyproline N-terminal).
Hyperiminopeptiduria; low or absent prolidase activity
in leukocytes or fibroblasts.
First symptoms appear between birth and 22 years
of age; prognosis, age of onset, and severity of the lesions are highly
variable: skin lesions: rash with diffuse telangiectasia, ecchymosis, difficult to cure
leg ulcers; characteristic facies: prominent skull sutures, ptosis and proptosis; recurrent infections of the skin,
chronic ear and sinus infections; impaired motor or cognitive development may be present. Treatment: oral
ascorbate or manganese is useful for the treatment of skin lesions.
Presence of foci of chronic
Careful positioning because of fragile
skin and the presence of ulcers.
There are no known pharmacological
Larsson A, Jaeken J: Disorders in the metabolism of glutathione and
imidazole peptides, in Fernandes J, Saudubray J-M, Van den Bergh G (eds):
Inborn Metabolic Diseases. 3rd ed. Berlin, Springer, 2000, p 312.