Missense variants in the Arg206 residue of <i>HNRNPH2</i>: Further evidence of causality and expansion of the phenotype
Angela Peron, Francesca Novara, Francesca La Briola, Elisabetta Merati, Emanuela Giannusa, Elena Segalini, Gloria Anniballi, Aglaia Vignoli, Roberto Ciccone, Maria Paola Canevini
Abstract
Missense variants in HNRNPH2 cause Bain type syndromic X-linked intellectual disability (XLID). To date, only six affected females and three affected males have been reported in the literature, and the phenotype has yet to be delineated in detail. Here, we report on a 35-year-old female with a novel de novo variant in HNRNPH2, providing further evidence that missense changes in the nuclear localization sequence cause Bain type XLID and that aminoacid 206 likely represents a mutational hotspot. We expand the phenotype of Bain type XLID to include breathing, sleep and movement disorders, cerebellar vermis hypoplasia, stereotypies, and hypersensitivity to noise. Our data indicate that the phenotype may be broader and more variable than initially reported, and suggest Rett syndrome as a possible differential diagnosis.