Genetic and phenotypic heterogeneity of Multiple Lentigines: Chinese families pave the path to accurate diagnosis

The study describes four unrelated Chinese families with hereditary multiple lentigines (ML) as their first symptom. ML is a condition where patients have multiple brown macules due to the accumulation of melanin in the skin. The study performed whole-exome sequencing (WES) and Sanger sequencing on all patients and identified two novel variants in SASH1 and two recurrent variants in PTPN11, which are associated with ML. The study emphasizes the importance of molecular diagnosis in the clinical differential diagnosis, genetic counseling, and prognosis of ML. The study also provides a summary of genes associated with ML and differential diagnosis of pigment abnormalities.