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Palmer E, Stepien KM, Campbell C, Barton S, Iosifidis C, Ghosh A, Broomfield A, Woodall A, Wilcox G, Sergouniotis PI, Black GC. Clinical, biochemical and molecular analysis in a cohort of individuals with gyrate atrophy. Orphanet J Rare Dis 2023; 18:265. [PMID: 37667371 PMCID: PMC10476330 DOI: 10.1186/s13023-023-02840-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/21/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Gyrate atrophy of the choroid and retina is a rare autosomal recessive metabolic disorder caused by biallelic variants in the OAT gene, encoding the enzyme ornithine δ-aminotransferase. Impaired enzymatic activity leads to systemic hyperornithinaemia, which in turn underlies progressive chorioretinal degeneration. In this study, we describe the clinical and molecular findings in a cohort of individuals with gyrate atrophy. METHODS Study participants were recruited through a tertiary UK clinical ophthalmic genetic service. All cases had a biochemical and molecular diagnosis of gyrate atrophy. Retrospective phenotypic and biochemical data were collected using electronic healthcare records. RESULTS 18 affected individuals from 12 families (8 male, 10 female) met the study inclusion criteria. The median age at diagnosis was 8 years (range 10 months - 33 years) and all cases had hyperornithinaemia (median: 800 micromoles/L; range: 458-1244 micromoles/L). Common features at presentation included high myopia (10/18) and nyctalopia (5/18). Ophthalmic findings were present in all study participants who were above the age of 6 years. One third of patients had co-existing macular oedema and two thirds developed pre-senile cataracts. Compliance with dietary modifications was suboptimal in most cases. A subset of participants had extraocular features including a trend towards reduced fat-free mass and developmental delay. CONCLUSIONS Our findings highlight the importance of multidisciplinary care in families with gyrate atrophy. Secondary ophthalmic complications such as macular oedema and cataract formation are common. Management of affected individuals remains challenging due to the highly restrictive nature of the recommended diet and the limited evidence-base for current strategies.
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Affiliation(s)
- Eleanor Palmer
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Karolina M Stepien
- Adult Inherited Metabolic Disorders, Salford Royal NHS Foundation Trust, Salford, Greater Manchester, UK
- Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Christopher Campbell
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Stephanie Barton
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Christos Iosifidis
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Arunabha Ghosh
- Willink Biochemical Genetics, Royal Manchester Children's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Alexander Broomfield
- Willink Biochemical Genetics, Royal Manchester Children's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Alison Woodall
- Adult Inherited Metabolic Disorders, Salford Royal NHS Foundation Trust, Salford, Greater Manchester, UK
- Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Gisela Wilcox
- Adult Inherited Metabolic Disorders, Salford Royal NHS Foundation Trust, Salford, Greater Manchester, UK
- Division of Diabetes, Endocrinology and Gastroenterology, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Panagiotis I Sergouniotis
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
| | - Graeme C Black
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
- Manchester Centre for Genomic Medicine, Saint Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Santinelli R, Costagliola C, Tolone C, D'Aloia A, D'Avanzo A, Prisco F, Perrone L, del Giudice EM. Low-protein diet and progression of retinal degeneration in gyrate atrophy of the choroid and retina: a twenty-six-year follow-up. J Inherit Metab Dis 2004; 27:187-96. [PMID: 15159649 DOI: 10.1023/b:boli.0000028779.29966.05] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Gyrate atrophy of the choroid and retina is an autosomal recessive chorioretinal dystrophy which leads to a slowly progressive loss of vision. The primary defect is due to a deficiency of the enzyme ornithine delta-aminotransferase, which is responsible for markedly elevated levels of ornithine in plasma and other body fluids. Although several therapeutic regimens have been proposed, the reduction in ornithine accumulation obtained by reducing the intake of its precursor arginine (semisynthetic low-arginine diet) is the one most practised. In this clinical and molecular study we report a patient with hyperornithinaemia and gyrate atrophy of the choroid and retina who had been diagnosed when she was 3 years 9 months old. She also presented mild mental retardation, delayed language development and speech defects. The patient has recently been found to be homozygous for the new Gly91Arg amino acid substitution of the enzyme ornithine delta-aminotransferase. This mutation lies in a region of the mature protein that is considered crucial for the mitochondrial targeting activity. In this patient, a 28-year treatment with a completely natural low-protein diet (0.8 g/kg per day of natural protein) has been able to significantly reduce ornithine plasma levels, and to greatly delay the natural progression of the chorioretinal changes. This study suggests that, in the long-term treatment of gyrate atrophy, the efficacy in slowing the progression of chorioretinal changes and the palatability of a completely natural low-protein diet make this treatment a potentially viable alternative in patients refusing the semisynthetic diet.
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Affiliation(s)
- R Santinelli
- Department of Pediatrics, Second University of Naples, Naples, Italy
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Wang T, Steel G, Milam AH, Valle D. Correction of ornithine accumulation prevents retinal degeneration in a mouse model of gyrate atrophy of the choroid and retina. Proc Natl Acad Sci U S A 2000; 97:1224-9. [PMID: 10655512 PMCID: PMC15576 DOI: 10.1073/pnas.97.3.1224] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deficiency of ornithine-delta-aminotransferase (OAT) in humans results in gyrate atrophy of the choroid and retina (GA), an autosomal recessive disorder characterized by ornithine accumulation and a progressive chorioretinal degeneration of unknown pathogenesis. To determine whether chronic, systemic reduction of ornithine can prevent this form of retinal degeneration, we used an arginine-restricted diet to maintain long term reduction of ornithine in a mouse model of OAT-deficiency (Oat(-/-)) produced by gene targeting. We evaluated the mice over a 12-month period by measurement of plasma amino acids, electroretinograms, and retinal histologic and ultrastructural studies. We found that an arginine-restricted diet substantially reduces plasma ornithine levels and completely prevents retinal degeneration in Oat(-/-). This result indicates that ornithine accumulation is a necessary factor in the pathophysiology of the retinal degeneration in GA and that restoration of OAT activity in retina is not required for effective treatment of GA.
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Affiliation(s)
- T Wang
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Hayasaka S, Saito T, Nakajima H, Takahashi O, Mizuno K, Tada K. Clinical trials of vitamin B6 and proline supplementation for gyrate atrophy of the choroid and retina. Br J Ophthalmol 1985; 69:283-90. [PMID: 3922397 PMCID: PMC1040584 DOI: 10.1136/bjo.69.4.283] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Five patients with gyrate atrophy of the choroid and retina were examined ophthalmologically, especially ophthalmoscopically, to evaluate trials of vitamin B6 (pyridoxine) or supplementary proline. The oral administration of vitamin B6 was tried in two patients. The vitamin did not alter the serum ornithine level and the progression of chorioretinal atrophy in one patient (case 2). Despite a reduced serum ornithine level following vitamin B6 administration, chorioretinal atrophy progressed gradually in another patient (case 3). Supplementary proline was tried in four patients. Despite the supplementation the serum proline level did not increase, and the chorioretinal atrophy progressed in one patient (case 2) who received both vitamin B6 and proline. Supplementary proline minimised the progression of gyrate atrophy in the youngest patient (case 1) and halted the progression in two others (cases 4 and 5). Supplementary proline may possibly lessen the progression of chorioretinal lesions in gyrate atrophy.
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Kaiser-Kupfer MI, Ludwig IH, de Monasterio FM, Valle D, Krieger I. Gyrate atrophy of the choroid and retina. Early findings. Ophthalmology 1985; 92:394-401. [PMID: 3991128 DOI: 10.1016/s0161-6420(85)34022-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Examination of two sisters ages 2 years 10 months and 6 years four months with gyrate atrophy of the choroid and retina provided an opportunity for detailed clinical investigation. Although the chorioretinal lesions were confined to the peripheral retina in the older case and were quite minimal in the younger case, there was electroretinographic evidence of marked involvement of the cone and rod systems. These cases offer an opportunity to assess an arginine restricted diet in preventing the progress of the disease.
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van der Heiden C, Beemer FA, van Dijk HA, Desplanque J, Gerards LJ. A lethal neonatal variant of carbamoyl-phosphate synthetase deficiency in combination with an intermediate activity of L-ornithine: 2-oxoglutarate amino-transferase. Clin Genet 1983; 23:363-8. [PMID: 6851228 DOI: 10.1111/j.1399-0004.1983.tb00447.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Shortly after birth, a newborn girl developed anorexia, hypotonia, apneic attacks and seizures. After 61 h the child died in coma. Biochemically, a highly elevated blood ammonia level was found together with an increased plasma level of the amino acids mainly involved in ammonia detoxication. Enzyme studies in post-mortem liver tissue material revealed a deficiency of carbamoyl-phosphate synthetase (0.9% of the mean value in controls) in combination with an intermediate activity of L-ornithine: 2-oxoglutarate aminotransferase (40% of the mean value in controls).
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Gray RG, Hill SE, Pollitt RJ. Studies on the pathway from ornithine to proline in cultured skin fibroblasts with reference to the defect in hyperornithinaemia with hyperammonaemia and homocitrullinuria. J Inherit Metab Dis 1983; 6:143-8. [PMID: 6422153 DOI: 10.1007/bf02310868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The reduction in the conversion of ornithine to proline by fibroblasts from a patient with hyperornithinaemia with hyperammonaemia and homocitrullinuria cannot be explained by a reduced uptake of exogenous ornithine, an altered total intracellular ornithine content, or reduced conversion of gamma-glutamate semialdehyde to proline. However, neither could the postulated defect in mitochondrial ornithine uptake be demonstrated using the digitonin method. Increasing the ornithine concentration in the medium increased the incorporation of 14C label from ornithine into protein in both the patient's and control cells. In the patient's cells the apparent Km for ornithine was ten times that of the controls, although the Vmax values were comparable. This result parallels the clinical response to ornithine supplementation.
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Arshinoff SA, McCulloch JC, Macrae W, Stein AN, Marliss EB. Amino acids in retinitis pigmentosa. Br J Ophthalmol 1981; 65:626-30. [PMID: 7295629 PMCID: PMC1039610 DOI: 10.1136/bjo.65.9.626] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A survey of fasting whole blood amino acids in 65 patients with various subtypes of retinitis pigmentosa performed. Eight X-linked recessive patients showed decreased taurine and aspartate. Nineteen autosomal recessive patients, and to lesser extent 10 autosomal dominant patients, showed reduced levels of whole blood threonine and histidine. Branched-chain amino acids and arginine were present in increased amounts in 2 patients with Laurence-Moon-Bardet-Biedl syndrome. These findings in LMBB patients are probably related in part to their obesity and emphasise that appropriate controls are required, and other factors (including age) known to affect amino acid levels must be accounted for. The biochemical implications of our findings are not yet apparent.
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