Further phenotypic and genetic variation in ADULT syndrome

ADULT (Acro-dermato-ungual-lacrimal-tooth) syndrome is characterized by ectrodactyly, syndactyly, fingernail and toenail dysplasia, hypoplasia of the breast and nipple, excessive freckling, lacrimal duct atresia, frontal alopecia, primary hypodontia, and/or early loss of permanent teeth. It is a rare autosomal dominant disorder which has been linked to mutation in the p63 gene. The p63 gene has been described in five overlapping limb malformation syndromes including the EEC syndrome (ectodermal ectrodactyly clefting). We report on the first case of ADULT syndrome of a mother and daughter with a new mutation R227Q in exon 6 of the p63 gene. This has not been previously associated with ADULT syndrome but only seen in EEC. In addition to the previously reported features of ADULT syndrome this report also describes some additional findings including hyperextensibility at the distal interphalageal joints, bilateral thumb duplication, bifid toenails, symptoms of urinary retention, vesicoureteric reflux, prominent ears, conductive hearing loss, and an overgrowth of a patch of hair in the midline of the neck. This report expands the knowledge of genotype-phenotype data on the p63 gene and suggests there may be a considerable overlap between the EEC syndrome and the ADULT syndrome.