Nuclear and cytoplasmic localization of ß-catenin in the nail-matrix cells and in an onychomatricoma.

ß-catenin plays an important role in hair morphogenesis. Previously, the nuclear and cytoplasmic localizations of ß-catenin were identified in hair-matrix cells. To evaluate ß-catenin expression in the nail matrix, we obtained human nail units. Immunohistochemistry for ß-catenin was used to evaluate sections of normal nail units and of sections from a single case of onychomatricoma. In the nail unit, ß-catenin was expressed in the nucleus and cytoplasm of the suprabasal nail-matrix cells. Of the other epithelial-cell types, only the cell membrane was ß-catenin-positive. In the nail tissue from the onychomatricoma case, ß-catenin was expressed in the nucleus and cytoplasm of the upper epithelial layers. Our result suggests that ß-catenin plays an important role in nail formation. In addition, ß-catenin expression in onychomatricoma supports the presence of nail-matrix cells in this condition. To our knowledge, this is the first report of ß-catenin expression in the nucleus and cytoplasm of the nail matrix.

Trichorhinophalangeal syndrome, type II (Langer-Giedion syndrome).

Trichorhinophalangeal syndrome (TRPS) is characterized by its unique facial features and skeletal abnormalities. A bulbous, pear-shaped nose, elongated philtrum, sparse hair, cone-shaped epiphyses and mild growth retardation are found in both type I (TRPSI) and type II (TRPSII). TRPSII can be distinguished from TRPSI when multiple exostoses or redundant skin are present. While TRPSI is inherited in an autosomal dominant fashion, most cases of TRPSII are sporadic although there are a few cases which are familial. The following is a case report of TRPSII with incomplete penetrance in the index case and exostoses and growth retardation in the patient's two siblings.