# Congenital Dermal Melanocytosis Exhibited in Two Patients with Hurler Syndrome: Clinical Characterization and Report of a Recurrent IDUA Allele in Colombia

## TL;DR

Two patients with Hurler syndrome showed skin melanocytosis and a common IDUA gene mutation, suggesting a link between skin signs and metabolic disorders in infants.

## Contribution

Reports a recurrent IDUA allele in Colombian Hurler syndrome patients with dermal melanocytosis.

## Key findings

- Two unrelated Hurler syndrome patients exhibited congenital dermal melanocytosis.
- Both patients shared the c.1045G>T (p.Asp349Tyr) IDUA mutation in a conserved position.
- Cutaneous signs may aid in early detection of lysosomal storage diseases in newborns.

## Abstract

The potential association of congenital dermal melanocytosis as a marker for lysosomal storage disease in infancy is rarely studied. A few cases of congenital dermal melanocytosis in association with lysosomal storage diseases have been reported. GM1 gangliosidosis type 1 and Hurler syndrome are the most common underlying lysosomal disorders associated with dermal melanocytosis. We present two non-relative patients with Hurler’s Syndrome who exhibited cutaneous manifestations. Both cases had a recurrent genetic variant c.1045G>T (p.Asp349Tyr) in the IDUA gene, located in a highly conserved amino acid position. We encourage the role of cutaneous findings in early suspicion and detection of inborn errors of metabolism, as well as differential diagnoses in a newborn with this finding.