Central nervous system neoplasm in a young man with Martin-Bell syndrome--fra(X)-XLMR.

A 17-year-old retarded male developed unilateral leg weakness with foot drop, pain, and incontinence. Workup disclosed a cauda equina tumor which, on surgical exploration, was demonstrated to merge with the conus medullaris. Pathological examination of the subtotally resected tumor led to a diagnosis of malignant ganglioglioma. Further evaluation of the patient documented marginal macro-orchidism, and chromosome studies showed fragile X. Since some neoplasms are known to be associated with chromosomal deletions and other abnormalities, we suggest that the occurrence of this tumor in this patient indicates a more than coincidental relationship between the two diagnoses.