Gyrate atrophy of the choroid and retina associated with hyperornithinaemia.

Abstract

The inheritance of the autosomal recessive type of gyrate atrophy of the choroid and retina seems well documented (Botermans, I 972), but the aetiology of the disease is still unknown.Animal experiments and some disturbances of lipid, carbohydrate, and protein metabolism connected with chorio-retinal degenerations in man support the possibility of an enzymatic disorder as an aetiological factor of these diseases (Franceschetti, Fran §ois, and Babel, I963; FranSois, I964).The present author recently diagnosed gyrate atrophy of the choroid and retina in an 8-year-old boy in whom an enlarged lysine-ornithine spot was found on the urine highvoltage electrophorogram in routine examination of urinary amino-acids. Further studies identified that the spot was ornithine. The plasma ornithine concentration was more than ten times higher than normal, although normal amounts of the other plasma aminoacids were present. A constant correlation between hyperornithinaemia and gyrate atrophy of the choroid and retina was then detected in nine other patients (Simell and Takki, I973).The purpose of this paper is to describe the different forms of gyrate atrophy found in a total of fifteen patients and to discuss the correlation of fundus changes with hyperornithinaemia. MaterialAn examination of case histories from I950 to 1972, with clinical diagnosis of any primary chorioretinal degeneration, revealed some thirty cases in which gyrate atrophy was suspected. Among them eleven cases of gyrate atrophy of the choroid and retina at different stages were found. Three additional cases were found among relatives of one patient and one further case was referred to the author. The total number of cases with gyrate atrophy of the choroid and retina described in this paper is thus fifteen, nine of which were included in our previous paper (Simell and Takki, I973). The characteristics of the patients are shown in Table I (overleaf). Among the ten families there were four sisters (Patients 6 and 9-I I) and two pairs of sisters (Patients 3, 5, and I 2-I3) and one of these was the first cousin of another patient (Patient 4).There were twenty intact and ten aphakic eyes, four of which were treated because of open-angle glaucoma. One eye was in postoperative phthisis after a cataract operation (Table II, overleaf).

A mouse model of gyrate atrophy of the choroid and retina. Early retinal pigment epithelium damage and progressive retinal degeneration.

“…In human GA patients, the ERG amplitude decreases gradually and is usually undetectable by the end of the second decade of life, at a time when there is still normal-appearing retina in the posterior pole (5,30). The mean ERG amplitude in the Oat Ϫ/Ϫ mice is normal at 2 mo of age but declines slowly to ‫ف‬ 40% of normal by the end of 1 yr.…”

“…In both, plasma ornithine concentrations are 10-15-fold higher and plasma lysine concentrations ‫ف‬ 50% lower than those of controls. As in humans, the magnitude of the ornithine accumulation in the Oat Ϫ/Ϫ mice is constant into old age (14,30). The reduction in lysine levels, characteristic of both Oat Ϫ/Ϫ mice and humans, is thought to result from decreased renal tubular reabsorption of lysine due to overflow ornithinuria (14).…”

Age‐related macular degeneration in Inuit

“…Gyrate atrophy of the chorioid and retina (GA) with hyperornithemia and a known defect of ornithine aminotransferase is the rare form of retinochorioidal dystrophies starting peripherally and progressing to the central retina and choroid with late sparing of the macula. The mode of inheritance is autosomal recessive (Vannas et al 1985;1987;Takki 1974). RCA is clinically a central type of retinochorioidal atrophy opposite to GA. A possible metabolic defect has not yet been established in RCA.…”

Atrofia girata de coróide e retina: relato de caso

“…Esta queda é geralmente decorrente de formação de catarata, principalmente subcapsular posterior, como verificado em nossa paciente. Alterações atróficas ou edema na mácula também podem levar à baixa de visão (2,(5)(6)8) . Cegueira legal geralmente ocorre por volta da quarta a sétima décadas de vida (5) .…”