Novel gene mutation and clinical features in a family with gyrate atrophy of choroid and retina / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the pathogenic mutations of the <i>OAT</i> gene in a Chinese family affected with gyrate atrophy of choroid and retina(GA)and describe their clinical manifestations.METHODS: All available family members have underwent detailed ophthalmological examinations. The sequencing results and pathogenic mutations were clarified by whole exome sequencing, bioinformatics analysis and Sanger sequencing.RESULTS: Based on the clinical manifestations and symptoms, the proband was diagnosed with GA. A missense mutation of c.722C>T(p.P241L)in exon 6 and a nonsense mutation of c.1186C>T(p.R396X)in exon 10 were identified in the <i>OAT</i> gene of the proband, which was a compound heterozygotic mutation. This compound heterozygous mutation showed co-segregation in the family. The heterozygous pathogenic variant of p.R396X was detected in both the proband's father and elder brother, and the heterozygous pathogenic variant of p.P241L was detected in proband's mother. Except for the proband, no other family members have abnormal clinical manifestations.CONCLUSION: The proband of this family is a compound heterozygous mutation, in which p.P241L is the first reported gene mutation type. This result expands the range of <i>OAT</i> gene variation and is conducive to further understanding the pathogenic factors of GA at the molecular basis level. The discovery and confirmation of the novel mutation type will also help to provide a new basis for the clinical diagnosis and gene therapy of GA.

Hiperornitinemia con atrofia gyrata de coroides y retina / Hyperornithinemia with gyrate atrophy of the choroid and retina

La atrofia gyrata de coroides y retina fue descrita por vez primera por Fuchs en el año 1896 como una entidad clínicamente definida. La deficiencia de la enzima ornitina delta aminotransferasa se hereda de forma autosómica recesiva; resulta en incremento plasmático de las concentraciones de ornitina y se asocia con atrofia gyrata de coroides y retina. Se presenta una paciente de 6 años de edad que es llevada a consulta, ya que en la escuela la maestra notaba mala visión de lejos. En un examen inicial del fondo de ojo el oftalmólogo observó cambios sugestivos de distrofia retiniana. En la oftalmoscopia binocular indirecta se encontraron extensas zonas confluentes de atrofia coroidea por fuera de las arcadas vasculares que respetaban el polo posterior; la mácula impresionaba normal. Se realizó un estudio de tomografía de coherencia óptica en dominio espectral en tomógrafo Spectralis que demostró la presencia de edema macular cistoide en ambos ojos. La determinación de niveles de ornitina en sangre arrojaron niveles muy elevados de este aminoácido (975 µmol/mL). Con todos estos hallazgos se llegó al diagnóstico de hiperornitinemia y atrofia gyrata de coroides y retina. Se indicó tratamiento dietético y vitamina B6 oral a pesar de que no se ha obtenido hasta el momento reducción significativa de los niveles de ornitina en plasma(AU)

Gyrate atrophy of the choroid and the retina was first described by Fuchs as a clinically defined condition in 1896. Human hereditary deficiency of ornithine aminotransferase activity is transmitted as an autosomal recessive trait and results in increased level of plasma ornithine and is associated with gyrate atrophy of the choroid and the retina. A 6-year-old girl was taken to the ophthalmologist’s because of her far poor vision detected by her teacher at the school. In the initial eye fundus examination the ophthalmologist observed some changes indicating retinal dystrophy. The indirect binocular funduscopy revealed extensive areas of choroidal atrophy outside the vascular archades respected the posterior pole whereas the macula impressed as normal. Cystoid macular edema was evident in both eyes according to the results of the optic coherence tomography performed with Spectralis tomograph. The aminoacid analysis revealed high serum ornithine level (975 µmol/mL). The clinical diagnosis of the patient was consistent with hyper-ornithinemia and gyrate atrophy of the choroid and the retina. She was treated with vitamin B6 and dietary supplementation but no significant reduction on her serum ornithine level was observed(AU)

Auxotrophy-Based Detection of Hyperornithinemia in Mouse Blood and Urine

Abstract Gyrate atrophy of the choroid and retina (GACR) is a hereditary form of progressive blindness caused by homozygosity for loss-of-function mutations in the ornithine aminotransferase gene (Oat). The high levels of circulating ornithine that lead to ophthalmic symptoms in young adults are also displayed by 2 ornithine aminotransferase (OAT)-deficient mouse models of GACR. Here, we have developed an inexpensive and quantitative bacteria-based test for detecting hyperornithinemia in blood or urine samples from these mutant mice, a test that we suggest could be used to facilitate the identification and treatment of OAT-deficient humans before the onset of visual impairment.

Gyrate Atrophy of the Choroid and Retina Diagnosed by Ornithine-delta-aminotransferase Gene Analysis: A Case Report

A pair of 19-year-old female identical twins was referred to our hospital with progressive visual loss. They exhibited bilateral chorioretinal atrophy involving the midperiphery on fundoscopy and fluorescein angiography. Bilateral visual field constriction was noted on dynamic Goldmann perimetry, and a markedly impaired response was observed on both photopic and scotopic electroretinograms. Cystoid macular edema was identified in both eyes on optical coherence tomography. Plasma levels of ornithine were elevated. Based on these observations, the patients were diagnosed with gyrate atrophy of the choroid and retina. The clinical diagnosis was confirmed by mutation analysis of the ornithine-delta-aminotransferase (OAT) gene. Patients were treated with a pyridoxine supplement (300 mg/day) and an arginine-restricted diet to lower plasma levels of ornithine, which were successfully reduced without progression of chorioretinal atrophy for 15 months. Our report describes the first case of gyrate atrophy in the Korean population diagnosed by OAT gene analysis and treated with vitamin B6 dietary supplementation.

Bilateral spontaneous dislocation of posterior chamber intraocular lens in a patient with gyrate atrophy.

We report a patient with gyrate atrophy, a rare metabolic disease, who had bilateral late spontaneous posterior dislocation of in-the-bag posterior chamber intraocular lens (PCIOL). He underwent pars plana vitrectomy, PCIOL retrieval and anterior chamber intraocular lens implantation in both eyes. This report may imply that patients with gyrate atrophy are at risk for spontaneous dislocation of intraocular lenses.

Retinal detachment and gyrate atrophy of the choroid and retina: case report / Descolamento de retina e atrofia girata da coroide e retina: relato de caso

To report a case of gyrate atrophy of the choroid and retina associated with retinal detachment. Hyperornithinemia confirmed the diagnosis of gyrate atrophy. Pars plana vitrectomy with silicone oil infusion was performed with good anatomical results, despite the persistence of low visual acuity. Retinal detachment is a rare complication of gyrate atrophy and can be managed with pars plana vitrectomy and silicone oil. We discuss the possible mechanisms that led to low visual acuity.

Descrever um caso de atrofia girata da coroide e retina associado com descolamento de retina. Altos níves de ornitina sérica confirmaram o diagnóstico de atrofia girata. Vitrectomia via pars plana com infusão de óleo de silicone foi realizada, com bom resultado anatômico, apesar da baixa acuidade visual persistente. Descolamento de retina é uma rara complicação da atrofia girata e pode ser manejada com vitrectomia via pars plana e óleo de silicone. Discutiremos os possíveis mecanismos que levaram à baixa acuidade visual.

Macular edema associated with gyrate atrophy managed with intravitreal triamcinolone: a case report

PURPOSE: To describe the use of 4 mg intravitreal triamcinolone acetonide (IVTA) for gyrate atrophy-related macular edema (ME) and to report anatomic and functional outcomes, during a nine-month period. CASE REPORT: A 27-year-old female complained of decreased vision since diagnosis of gyrate athrophy (GA), six years before admission. At presentation visual acuity was 20/100 in OD and 20/80 in OS. Ophthalmological examination disclosed significant cataract in OD, pseudophakia in OS and typical GA findings. Fluorescein angiography (FA) disclosed ME that was confirmed by optical coherence tomography (OCT), which also showed subfoveal fluid. OS was treated with a 4-mg IVTA injection. One month later, vision improved to 20/50+1 and foveal thickness decreased, with less leakage in FA. This picture was maintained up to six months, when there was recurrence of ME to a level similar to the baseline. At nine months, visual acuity dropped to 20/80, and ME was maintained, with remodeling in macular profile. CONCLUSION:There is a transient therapeutic effect with 4-mg IVTA injection for GA-related ME. After drug clearance, edema recurs, with return of visual acuity to pretreatment level.

OBJETIVO: Descrever o uso de acetonida de triancinolona intravítrea (TAIV) em caso de edema macular (EM) associado a atrofia girata (AG). RELATO DE CASO: Paciente de 27 anos, do sexo feminino, queixava-se de baixa de visão desde o diagnóstico de AG, há seis anos. À admissão, apresentava acuidade visual corrigida de 20/100 no OD e 20/80 no OE. Exame oftalmológico revelava catarata significativa no OD, pseudofacia no OE e achados típicos de AG. Angiografia fluoresceínica (AFG) mostrou EM, confirmado pela tomografia de coerência óptica (OCT), que também revelou líquido subfoveal. Foi então realizada injeção de 4 mg de TAIV no OE. Após um mês, a visão melhorou para 20/50+1 e a espessura foveal se reduziu, com menos extravasamento à AFG. Esse quadro foi mantido até os seis meses, quando houve recorrência do edema macular em nível semelhante ao inicial. Aos nove meses, a visão retornou a 20/80 e o edema se manteve, com remodelamento no perfil macular. CONCLUSÃO: A injeção de 4 mg de TAIV tem efeito transitório no EM associado a AG. Após a eliminação da droga, há recorrência do EM, com retorno da visão aos níveis pré-tratamento.