A family is described in which a 33-year-old man has classic X-linked recessive Fabry disease. His 2 sisters were discovered to be heterozygous carriers of the Fabry gene and to have both episodic and permanent neurological deficits including vertigo, tinnitus, long tract motor signs, and bladder incontinence. The most concise explanation for these findings is that the sisters manifest central nervous system complications of the Fabry carrier state. This family provides additional evidence that female carriers of rare X-linked recessive disorders may exhibit serious consequences of the disease, presumably related to tissue variability in expression of mutant enzyme activity.