Molecular analysis provides further evidence that Chitayat syndrome is caused by the recurrent p.(Tyr89Cys) pathogenic variant in the ERF gene.

Chitayat syndrome (CHYTS, MIM #617180) is a rare autosomal dominant clinical condition caused by a single missense pathogenic variant in the ERF gene (19q13.2, MIM*611888), which encodes the ETS2 Repressor Factor (ERF) protein. The characteristic features reported to date for this condition are facial dysmorphism, hyperphalangism and respiratory complications during the newborn period. Herein, we report the sixth patient worldwide with a confirmed molecular diagnosis of CHYTS. Our documentation of pectus carinatum, hypoplastic phalanges (as in two previously described patients), and lack of hyperphalangism broadens the phenotypic spectrum of CHYTS. Moreover, our identification of a heterozygous mutation [c.266A>G or p.(Tyr89Cys)] [rs886041001] in this patient provides further evidence that this condition is caused by a recurrent pathogenic variant in ERF.

Unique association of hypochondroplasia with craniosynostosis and cleft palate in a Mexican family.

Hypochondroplasia (HCH) is a skeletal dysplasia caused by an abnormal function of the fibroblast growth factor receptor 3. Although believed to be relatively common, its prevalence and phenotype are not well established owing to its clinical, radiological, and genetic heterogeneity. Here we report on a molecularly proven HCH family with an affected father and two children. The siblings (male and female) with HCH also had craniosynostosis and cleft palate, respectively. The present report supports the conclusion that the full clinical spectrum of HCH is not completely delineated. It also suggests that secondary, as yet unknown, modifying factors can influence the final phenotype.