An extremely rare syndrome with characteristics of hypoplastic thumbs and halluces, fifth finger brachydactyly, postaxial polydactyly of the hands, short or uniphalangeal second toes with absent nails and hypospadias. It has been described in a father and his son and daughter. The affected patients have normal mental development. Except for postaxial polydactyly of the hands and uniphalangeal second toes with absent nails, features are in common with hand-foot-genital syndrome caused by mutations in the HOXA13 gene. In all three affected individuals, two different sequence alterations were identified in HOXA13 gene: a de novo missense mutation and a deletion in the promoter region of the gene, inherited from an unaffected parent, which may contribute to the phenotype in the affected individuals. The condition is inherited in an autosomal dominant manner.