Speculations on vitamin K, VKORC1 genotype and autism.

Humans vary in the gene that encodes for Vitamin K epoxide reductase complex (VKORC1). Recent research has documented the protective effect of Vitamin K on neural cells and its role in maintaining normal neural development. Of interest, specific neural effects of Vitamin K overlap with key brain development aberrations, including those associated with autism. Furthermore, Vitamin K protects against oxidative stress associated with toxic exposure. Research on the neural effects is reviewed, and a small sample of severely autistic children of Somali descent residing in the Minneapolis/St. Paul area of Minnesota were genotyped and found to have a higher than expected genetic substitution that results in reduction in the efficiency of the Vitamin K cycle. The possibility that this genetic difference could play an etiological role in the development of autism is considered.