Supplementary Material for: CDH3-Related Syndromes: Report on a New Mutation and Overview of the Genotype-Phenotype Correlations

Hypotrichosis with juvenile macular dystrophy (HJMD) and ectodermal dysplasia, ectrodactyly and macular dystrophy (EEM) are both caused by mutations in the CDH3 gene. In this report, we describe a family with EEM syndrome caused by a novel CDH3 gene mutation and review the mutation spectrum and limb abnormalities in both EEM and HJMD. A protein structure model showing the localization of different mutations causing both syndromes is presented. The CDH3 gene was sequenced and investigation of the mutations performed using a protein structure model. The conservation score was calculated by ConSurf. We identified a novel CDH3 gene mutation, p.G277V, which resides in a conserved residue located on a β-strand in the second cadherin domain. Review of the data on previously published mutations showed intra-familial and inter-familial variations in the severity of the limb abnormalities. Syndactyly was the most consistent clinical finding present in all the patients regardless of mutation type. The results of our study point to a phenotypic continuum between HJMD and EEM. It is important for genetic counseling to keep in mind the possible clinical/phenotypic overlap between these 2 syndromes and to be aware of the possible risk of limb abnormalities in future pregnancies in families with HJMD syndrome. CDH3 gene mutation screening is recommended in patients with both these syndromes as part of the work-up in order to offer appropriate genetic counseling.