Evidence of central nervous system involvement in Watson syndrome.

In 1967, Watson described 3 families with an autosomal dominant condition characterized by pulmonary valvular stenosis, café-au-lait sports, and short stature. Presumed hamartomatous lesions have been observed in neurofibromatosis type I, but they were not reported to date in Watson syndrome. We report another family with Watson syndrome, in which 1 patient manifested increased intensity T2-weighted lesions on magnetic resonance imaging similar to those occurring in neurofibromatosis type I and possibly hamartomas. This finding demonstrates the overlap between neurofibromatosis type I and Watson syndrome and supports the hypothesis that those conditions are allelic or, less likely, that the gene that determines the Watson phenotype is very closely linked to the neurofibromatosis type I locus.