Mexican patient with Ellis‐van Creveld syndrome and cleft palate: Importance of functional hemizygosity and phenotype expansion

Background Ellis‐van Creveld syndrome (EvCS) is a chondroectodermal dysplasia caused by germline pathogenic variants in ciliary complex subunit 1 and 2 genes ( EVC , EVC2 ) on chromosome 4p16.2. This disease has a broad phenotype, and there are few described phenotype–genotype correlations. Methods Ethical Compliance: Written informed consent was obtained from the parents. Here, we report a genetically confirmed Mexican patient with EvCS having two inherited pathogenic variants in trans in EVC2 : c.[1195C>T];[2161delC]. Results This patient allowed a genotypic–phenotypic comparison with another Mexican subject who presented a more attenuated phenotype; furthermore, our patient also presented cleft palate, a rarely reported feature. Conclusion Our case shows the importance of comparing functional hemizygosity between patient's phenotypes when they share a variant, and our case also supports the association of alterations in the palate as part of the EvCS phenotype.