Muscle creatine phosphate in gyrate atrophy of the choroid and retina with hyperornithinaemia-clues to pathogenesis

• Published in: European journal of clinical investigation Vol. 29; no. 5; pp. 426 - 431
• Main Authors: HEINÄNEN, K, NÄNTÖ-SALONEN, K, KOMU, M, ERKINTALO, M, HEINONEN, O. J, PULKKI, K, VALTONEN, M, NIKOSKELAINEN, E, ALANEN, A, SIMELL, O
• Format: Journal Article
• Language: English
• Published: Oxford BSL Blackwell Science Ltd 01.05.1999; Blackwell; Blackwell Publishing Ltd
• Subjects: 31P-magnetic resonance spectroscopy; Adenosine Triphosphate - metabolism; Adolescent; Adult; Age Factors; Aged; Aminoacid disorders; Biological and medical sciences; Child; Child, Preschool; creatine; creatine phosphate; Errors of metabolism; Female; gyrate atrophy; Gyrate Atrophy - metabolism; Humans; hyperornithinaemia; Magnetic Resonance Spectroscopy; Male; Medical sciences; Metabolic diseases; Middle Aged; Muscle, Skeletal - metabolism; Ophthalmology; Phosphates - metabolism; Phosphocreatine - metabolism; Phosphorus Isotopes; retinitis pigmentosa; Retinitis Pigmentosa - metabolism; Retinopathies; Creatinine; Human; Phosphates; Retinopathy; Statistical analysis; Pathogenesis; Retinitis pigmentosa; Metabolic diseases; Choroid; Retina; Uvea disease; Hyperornithinemia; Atrophia gyrata; Striated muscle; Enzymopathy; Differential diagnostic; Genetic disease; Eye disease; Aminoacid disorder
• ISSN: 0014-2972; 1365-2362
• DOI: 10.1046/j.1365-2362.1999.00467.x

Background In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), inherited deficiency of ornithine‐δ‐aminotransferase leads to progressive fundus destruction and atrophy of type II skeletal muscle fibres. Because high ornithine concentrations inhibit creatine biosynthesis, the ensuing deficiency of high‐energy creatine phosphate may mediate the pathogenesis. Materials and methods Relative concentrations of inorganic phosphate (Pi), creatine phosphate (PCr) and ATP in resting calf muscle were recorded in 23 GA patients and 33 control subjects using 31P‐magnetic resonance spectroscopy (MRS). Eight patients with autosomal recessive retinitis pigmentosa with matched control subjects constituted an additional reference group. Results The PCr/Pi and PCr/ATP ratios (means ± SD) were lower for the GA patients than for healthy control subjects [4.66 ± 0.37 vs. 9.75 ± 2.17 (P < 0.0001) and 2.85 ± 0.37 vs. 3.70 ± 0.50 (P < 0.05) respectively]. In retinitis pigmentosa the respective values were 9.12 ± 2.57 and 4.25 ± 0.45. Age and stage of the disease had no effect. Conclusion Muscle 31P‐MRS spectra were markedly abnormal in all GA patients.