Multidisciplinary Approach for Mapping Genetic Variants in Naevoid Basal Cell Carcinoma Syndrome. Newly Identified Patched 1 Mutations in Half-Sisters

Objective: Naevoid basal cell carcinoma syndrome is a rare and autosomal dominant inherited condition with variable expressivity. Several genetic mutations have been identified but clear genotype-phenotype correlations have not been demonstrated; therefore, the diagnosis is still based on clinical criteria that may not be present or are not recognized. Numerous medical specialties have a role in the care of these patients, so the number of cases treated in a single center is usually low, thus making the implementation of standardized diagnostic and treatment protocols difficult.

Materials and Methods: A multidisciplinary research team was set up to collect and diagnose naevoid basal cell carcinoma syndrome patients according to the same principles. All patients suspected for this syndrome underwent the same diagnostic steps involving molecular genetic investigation.

Results: One of the first results of this study was the identification of a novel mutation of the patched-1 gene in two maternal half-siblings. Both patients fulfilled the specific criteria for diagnosis of naevoid basal cell carcinoma syndrome. Detailed descriptions of clinical, radiological, and genetic findings are given in this paper. Molecular genetic analysis identified a new deletion mutation in exon 13 of the Patched 1 gene in both half-siblings.

Conclusion: Genetic mapping of mutations can facilitate our understanding of the correlation between genetic background and clinical manifestations.