# Dyschromatosis universalis hereditaria with SASH1 mutation improved with picosecond laser treatment

## TL;DR

A Chinese boy with a rare skin condition called dyschromatosis universalis hereditaria showed significant improvement after picosecond laser treatment.

## Contribution

A novel SASH1 mutation was identified in a Chinese patient with DUH, and picosecond laser treatment was found to be effective for hyperpigmented lesions.

## Key findings

- A novel heterozygous SASH1 mutation (c.1529G > A) was identified in a Chinese boy with DUH.
- Picosecond laser treatment led to significant improvement in hyperpigmented lesions.
- Phenotypic variability in SASH1-associated DUH suggests roles for additional genetic or environmental factors.

## Abstract

Dyschromatosis universalis hereditaria (DUH) is a rare autosomal dominant pigmentary skin disorder characterized by hypo- and hyperpigmented macules over the body. Although DUH is associated with mutations in ABCB6 and SASH1, other factors also contribute to the pathogenesis of DUH, as the lesions typically appear on the exposed areas of the skin and do not develop in all individuals with SASH1 mutations. Most reported cases of SASH1 mutations are in Chinese or Japanese patients who do not require treatment. Herein, we report a rare case of an 11-year-old boy presenting with an 8-year history of widespread brown spots. The lesions, which began on his face and spread to the trunk, limbs and oral mucosa, developed without photosensitivity. Whole-exome sequencing helped identify a heterozygous SASH1 mutation (c.1529G > A; exon13, NM_015278.5). Initial treatment with intense pulsed light did not result in any improvement; however, subsequent picosecond laser treatment led to significant improvement. Hence, this case highlights the phenotypic variability of DUH associated with SASH1 mutations and the potential role played by additional genetic or environmental factors in disease expression. Furthermore, picosecond laser treatment may be effective against hyperpigmented lesions, although further studies are required to assess its long-term efficacy and safety.

We identified a novel pathogenic mutation in SASH1 in a Chinese boy with DUH, thus further expanding the mutation spectrum of this gene in DUH. We demonstrated that picosecond laser treatment is a safe and effective method of treating hyperpigmented lesions in patients with DUH.