Neurologic complications in galactosemia.

Two siblings, a 27-year-old man and his 24-year-old sister were diagnosed with classic transferase deficiency galactosemia at birth and were treated with strict lactose restriction. Despite well-documented dietary management, both siblings are mentally retarded and manifest a progressive neurologic condition characterized by hypotonia, hyperreflexia, dysarthria, ataxia, and a postural and kinetic tremor. Magnetic resonance imaging revealed moderate cortical atrophy, a complete lack of normal myelination, and multifocal areas of increased signal in the periventricular white matter on T2-weighting. These patients suggest that even with early diagnosis and treatment, individuals with galactosemia may have significant neurologic morbidity with abnormalities of white matter development. This finding raises the possibility of biochemical heterogeneity within the classic transferase deficiency group, as well as the possibility of a lack of available galactose metabolites necessary for glycolipid synthesis causing a disruption of normal myelin development.