Prolidase Deficiency in a Mexican-American Patient Identified by Array CGH Reveals a Novel and the Largest PEPD Gene Deletion.

Prolidase deficiency (PD) is a rare genetic disorder caused by mutations in the peptidase D (PEPD) gene, affecting collagen degradation. Features include lower extremity ulcers, facial dysmorphism, frequent respiratory infections, and intellectual disability, though there is significant intra- and interfamilial variability. Twenty-eight mutations have been previously reported, all either small deletions/duplications or point mutations discovered by enzyme or DNA assays. PD has been reported in patients of various ethnic backgrounds, but never in the Mexican-American population. We describe the first Mexican-American patient with PD, who presented with typical facial features, developmental delay, microcephaly, and xerosis. Chromosome microarray analysis (CMA) revealed a homozygous deletion in the region of 19q13.11, estimated to be between 124.79 and 195.72 kb in size, representing the largest PEPD gene deletion reported to date and the first discovered by CMA.