A de novo heterozygous HOXA11 variant in a patient with mesomelic dysplasia with urogenital abnormalities

Mesomelic dysplasias are a genetically and clinically heterogeneous group of diseases with more than 10 types defined. This article presents an 18-year-old female patient with normal intelligence and a multisystem phenotype including disproportionate short stature, scoliosis, mesomelic limb shortening, radial bowing, short fourth to fifth metacarpals and metatarsals, fusions in the carpal/tarsal bones, operated pes equinovarus, primary amenorrhea, uterine hypoplasia, vesicoureteral reflux, and chronic kidney disease. Whole-exome sequencing revealed a de novo heterozygous c.881T>G (p.Met294Arg) variant in HOXA11 (NM_005523.6) gene. The variant was located in the homeodomain of HOXA11 and predicted to alter DNA-binding ability of the protein. In silico analyses indicated that the variant could promote the alterations in the protein-protein interaction. The possible functional effect of the variant was supposed as dominant-negative. Hoxa11-mutant mice have been reported to exhibit homeotic transformations in the thoracic and sacral vertebrae, zeugopodal phenotype in forelimb and hindlimb, and urogenital abnormalities. Although mice models were reported as mesomelic dysplasia and urogenital abnormalities (MDUGA), this phenotype has not yet been reported in humans. This was the first case with MDUGA putatively related to a de novo variant in HOXA11.