Gyrate atrophy of the choroid and retina with hyperornithinemia, cystinuria and lysinuria responsive to vitamin B6

Ornithine Aminotransferase, an Important Glutamate-Metabolizing Enzyme at the Crossroads of Multiple Metabolic Pathways

“…Although in the large majority of cases cognition is unimpaired, a few patients have been described with mental retardation [220]. Biologically, patients with GA display an increase in plasma Orn concentration (10–20-fold) [194], and in some cases present an overflow ornithinuria, lysinuria and cystinuria when plasma Orn exceeds 400 µmol/L [221,222]. It is noteworthy that the increase in plasma Orn occurs after the first 3 months of life [204]; the importance of this metabolic feature is underlined below.…”

“…These are an Arg-restricted diet [230], and vitamin B6 supplementation in cases of vitamin B6-responsive phenotype, which concerns a minority of patients [222,231]. The link between genetic mutations and response to treatment is still unclear.…”

Multimodal characterization of a novel mutation causing vitamin B6-responsive gyrate atrophy

“…Of the approximately 70 cases of GA reported in Finland, zero patients have responded to vitamin B6 22 . From additional studies worldwide, a total of 9 patients have been reported to respond to vitamin B6 13, 23 . Thus, the patient presented in this study is a rare case that responded to vitamin B6 supplementation.…”

Seguimiento bioquímico y dosis de medicamentos de EIM del metabolismo intermedio

“…En la enfermedad de orina con olor a jarabe de maple (arce), causada por una deficiencia en la actividad del complejo de la deshidrogenasa de los alfa cetoácidos de cadena ramificada, cuyo cofactor es la tiamina tampoco, se ha documentado que exista una respuesta favorable con la suplementación en mega dosis. 9,10,11 Cuadro 1 [12][13][14][15][16][17][18][19][20] La terapia de remplazo enzimático se administra de forma intravenosa con enzimas recombinantes y ha sido exitosa en enfermedades de depósito lisosomal tales como la enfermedad de Gaucher y Fabry. Actualmente, algunas enzimas bacterianas modificadas tales como el pegvaliase se están empezando a utilizar por vía subcutánea, como la nueva terapia de sustitución enzimática para pacientes con fenilcetonuria.…”

“…Errores innatos del metabolismo intermedio que responden a megadosis de coenzimas. [12][13][14][15][16][17][18][19][20]…”