A rare cause of immune dysregulation, prolidase deficiency: a case report and review of the literature.

We report a pediatric patient with prolidase deficiency, caused by a mutation in the PEPD gene, which encodes the enzyme prolidase D, with a lupus-like clinic and marked dysmorphic features along with pulmonary, neurological, skeletal, and immune system involvement. In addition to being the first known case in the literature where Friedrich's ataxia and prolidase deficiency were observed together, we aimed to highlight that this diagnosis should be considered in patients with autoimmunity and additional systemic findings such as treatment-resistant skin lesions, intellectual disability, and pulmonary manifestations. Furthermore, we sought to compare this case with others documented in the literature.