Fig. 10 A. Left eye of a 12-year-old girl with B6-nonresponsive gyrate atrophy of the choroid and retina. One allele of the ornithine aminotransferase gene was inactivated by a (TAC)Tyr299-TAG stop mutation in exon 8, whereas the other allele was inactivated by an Arg180Thr (AGG→ACG) mutation in exon 6 (patient 4 in reference 61). B. Left eye of a 30-year-old woman with B6-responsive gyrate atrophy. One allele of the ornithine aminotransferase gene was the Glu318Lys mutation (GAG → AAG mutation at codon 318 in exon 9), whereas the other allele was inactivated by a splice site mutation of intron 4.62 C. Right eye of a 40-year-old man with B6-nonresponsive gyrate atrophy, showing accumulation of dense, black pigment in the temporal periphery in region of choroidal atrophy. One allele was inactivated by a deletion within exon 6, whereas the other was inactivated by formation of a stop codon in exon 6 (TAT)Tyr209TAA.61 (A, B, and C from Weleber RG, Kennaway NG: Gyrate atrophy of the choroid and retina. In Heckenlively JR [ed]: Retinitis Pigmentosa. Philadelphia: JB Lippincott, 1988:198–220)