A syndrome is characterized by symmetric, nonopposable triphalangeal thumbs and radial hypoplasia. It has been described in eight patients (five females and three males) spanning generations of a family. The affected males also presented with hypospadias. The syndrome is inherited as an autosomal dominant trait. The disease is Monarch Disease Ontology entry MONDO_0008357 (radial hypoplasia-triphalangeal thumbs-hypospadias-maxillary diastema syndrome). Also known as: Schmitt Gillenwater Kelly syndrome, Schmitt-Gillenwater-Kelly syndrome, radial hypoplasia triphalangeal thumbs hypospadias maxillary diastema, radial hypoplasia, triphalangeal thumbs, hypospadias, and maxillary diastema.