Atypical Gyrate Atrophy of the Choroid and Retina Associated With Iminoglycinuria

Differential diagnosis of normoornithinaemic gyrate atrophy of the choroid and retina

“…In a comprehensive study on tapetoretinal degenerations in Ailand islanders, Forsius & Eriksson (1970) found a case with a fundus picture very much like that in GA. Followup examinations revealed no elevation of plasma ornithine (Forsius, personal communication) and the finding was interpreted as a variation of retinitis punctata albescens. Hayasaka et al (1982) presented a case with a fundus appearance similar to GA. Other findings were a macular lesion, patchy atrophy of the irides and abnormal ciliary processes. The patient had iminoglycinuria but no hyperornithinaemia.…”

A Fukuyama type of congenital muscular dystrophy associated with atypical gyrate atrophy of the choroid and retina: A case report

“…So it may be reasonable to consider that our case is a new type of gyrate atrophy associated with FCMD or an atypical gyrate atrophy incidentally combined with FCMD. Mizuno (1981) and Hayasaka et al (1982) speculated that the pathway from ornithine to proline in the ocular tissue must be disturbed on account of the deficiency of OKT in typical gyrate atrophy. They also thought that proline and hydroxyproline are major constituents of collagen, and that congeital deficiency of proline may lead to clinical changes resembling gyrate atrophy in the uveal tract and retina.…”

Proline metabolism and transport in retinal health and disease

“…The OAT deficiency causes over tenfold accumulation of ornithine in the plasma, which in vitro has been shown to inhibit P5CS (Hu et al 1999). Excessive proline with normal ornithine in the urine is correlated with atypical gyrate atrophy in patients, suggesting that proline is deficient in the RPE (Hayasaka et al 1982;Saito et al 1981). Oral supplementation of ornithine significantly increases plasma proline in healthy controls but not in patients with gyrate atrophy.…”