['Prolidase deficiency is a complex disease characterized by various skin manifestations accompanied by mental retardation, facial dysmorphism and susceptibility to pyogenic infections.', 'We assessed a patient presenting a peculiar phenotype combining manifestations of prolidase deficiency with features typical of hyper-IgE syndrome. Mutation analysis was performed using direct PCR amplification and PCR restriction fragment length polymorphism analysis.', 'We identified a novel homozygous recessive mutation in the PEPD gene, which was found to segregate in the family of the patient with the disease and was not found in a panel of DNA samples representative of all major Druze families living in northern Israel.'] Does a homozygous missense mutation in PEPD encoding peptidase D cause prolidase deficiency associated with hyper-IgE syndrome?