Abstract
INTRODUCTION: Prolidase deficiency is a rare multisystemic disease associated with collagen metabolism. Clinical manifestations and age of onset are highly variable. Prolidase deficiency is caused by homozygous variants in the PEPD gene. In this report, three siblings with c.1103T>G (L368R) variant in the PEPD gene are presented. They had features not described in the literature and marked intrafamilial clinical heterogeneity. This is the first family of Syrian ancestral origin with prolidase deficiency. CASE PRESENTATION: We performed whole-exome sequencing for the index case, and detected a homozygous c.1103T>G variant, in the PEPD gene. All family members were then screened for the same variant by Sanger sequencing analysis. Two siblings were found to be homozygous, and one of them had not yet developed clinical symptoms. CONCLUSION: Our data expand the clinical spectrum of prolidase deficiency. It also improves our knowledge of phenotype and genotype relationships of prolidase deficiency patients.