Glutaric acidemia type I (GA-I) is an autosomal recessive disorder of the catabolism of lysine, hydroxylysine, and tryptophan caused by deficiency of glutaryl-CoA dehydrogenase (GCD). Among our patients with GA-I, we noted a prevalence of Lumbee individuals. The Lumbee are a close-knit Native American tribe of eastern North Carolina. Five Lumbee individuals with GA-I had homozygous 1240G>A mutations in GCD. This is a rare, known mutation that was likely introduced by a Lumbee founder.