Abstract
A 19-year-old female patient, diagnosed with generalized lentiginosis and the right renal dysplasia, had all other systems found to be normal. Whole exome sequencing identified double heterozygous missense mutations, c.1029C > T and c.1566C > A, in the SASH1 gene. Her parents each carry a single-site mutation, c.1029C > T, and do not exhibit the similar lentiginous phenotype. According to the literature, both mutation sites are unprecedented, with the c.1566C > A variation representing a novel occurrence within this lineage. The primary pathogenic mutation was identified at c.1566C > A, while the evidence for the pathogenicity of c.1029C > T remains insufficient. There are currently no reported cases in the literature where this gene mutation has led to such symptoms. This finding not only contributes to the expansion of the human gene mutation repository but also provides crucial insights for the genetic counseling of the patient and her relatives. During these consultations, it is essential to elucidate the characteristics and implications of these mutations to accurately gauge the patient's risk factors and inform future familial health decisions.