- At least two mutant alleles of ornithine delta-aminotransferase cause gyrate atrophy of the choroid and retina in Finns. Mitchell, G.A., Brody, L.C., Sipila, I., Looney, J.E., Wong, C., Engelhardt, J.F., Patel, A.S., Steel, G., Obie, C., Kaiser-Kupfer, M. Proc. Natl. Acad. Sci. U.S.A. (1989)