Abstract：
BACKGROUND: Oguchi disease is a rare autosomal recessive form of congenital quiescent night blindness. Oguchi disease has been found to be associated with gene mutations in SAG and GRK1, which are vital factors in the recovery phase of phototransduction after light stimuli. We report a case of Oguchi disease with novel heterozygous mutations in SAG.
METHODS: A 7-year-old girl with a history of night blindness since childhood, was referred to our hospital. Ophthalmologic examinations included visual acuity, fundus examinations, fundus photography, spectral-domain optical coherence tomography, electroretinographic (ERG). Mutation screening of the SAG and GRK1 genes was performed. This patient exhibited typical clinical characteristics of Oguchi disease, including night blindness, golden fundus with the Mizuo-Nakamura phenomenon, packed structure of the parafovea in optical coherence tomography and reduced a-waves and b-waves in scotopic 3.0 ERG. Genetic testing revealed a heterozygous change in nucleotide c.72_75+15delATCGGTGAGTGGTGCACAA in exon 2 of the SAG gene in this patient, her unaffected mother and younger brother. A splicing alteration of nucleotide c.376-2A>C was identified in exon 6 of the SAG gene with heterozygous status in this patient and her unaffected father.
CONCLUSIONS: Compound heterozygosity of a nonsense p.S25X mutation in exon 2 and a splicing alteration in exon 6 of the SAG gene is the cause of this patient with Oguchi type 1 disease in China.
METHODS: A 7-year-old girl with a history of night blindness since childhood, was referred to our hospital. Ophthalmologic examinations included visual acuity, fundus examinations, fundus photography, spectral-domain optical coherence tomography, electroretinographic (ERG). Mutation screening of the SAG and GRK1 genes was performed. This patient exhibited typical clinical characteristics of Oguchi disease, including night blindness, golden fundus with the Mizuo-Nakamura phenomenon, packed structure of the parafovea in optical coherence tomography and reduced a-waves and b-waves in scotopic 3.0 ERG. Genetic testing revealed a heterozygous change in nucleotide c.72_75+15delATCGGTGAGTGGTGCACAA in exon 2 of the SAG gene in this patient, her unaffected mother and younger brother. A splicing alteration of nucleotide c.376-2A>C was identified in exon 6 of the SAG gene with heterozygous status in this patient and her unaffected father.
CONCLUSIONS: Compound heterozygosity of a nonsense p.S25X mutation in exon 2 and a splicing alteration in exon 6 of the SAG gene is the cause of this patient with Oguchi type 1 disease in China.
摘要：
背景：Oguchi病是一种罕见的常染色体隐性形式的先天性静态夜盲症。已发现Oguchi病与SAG和GRK1的基因突变有关，这是光刺激后光转导恢复阶段的重要因素。我们报告了一例在SAG中具有新的杂合突变的Oguchi病。
方法：一名7岁女孩，从小就有夜盲症史，被转诊到我们的医院。眼科检查包括视力，眼底检查,眼底摄影,谱域光学相干层析成像,视网膜电图（ERG）。进行SAG和GRK1基因的突变筛选。该患者表现出典型的Oguchi病临床特征，包括夜盲症,带有Mizuo-Nakamura现象的金色眼底，光学相干层析成像中旁瓣的堆积结构，并减少了暗型3.0ERG中的a波和b波。遗传检测显示该患者SAG基因外显子2的核苷酸c.72_7515delATCGGTGAGTGGGGCACAA杂合变化，她不受影响的母亲和弟弟。在该患者及其未受影响的父亲中，在SAG基因的外显子6中鉴定出核苷酸c.376-2A>C的剪接改变，具有杂合状态。
结论：SAG基因外显子2无义p.S25X突变和外显子6剪接改变的复合杂合性是该患者在中国患有Oguchi1型疾病的原因。
方法：一名7岁女孩，从小就有夜盲症史，被转诊到我们的医院。眼科检查包括视力，眼底检查,眼底摄影,谱域光学相干层析成像,视网膜电图（ERG）。进行SAG和GRK1基因的突变筛选。该患者表现出典型的Oguchi病临床特征，包括夜盲症,带有Mizuo-Nakamura现象的金色眼底，光学相干层析成像中旁瓣的堆积结构，并减少了暗型3.0ERG中的a波和b波。遗传检测显示该患者SAG基因外显子2的核苷酸c.72_7515delATCGGTGAGTGGGGCACAA杂合变化，她不受影响的母亲和弟弟。在该患者及其未受影响的父亲中，在SAG基因的外显子6中鉴定出核苷酸c.376-2A>C的剪接改变，具有杂合状态。
结论：SAG基因外显子2无义p.S25X突变和外显子6剪接改变的复合杂合性是该患者在中国患有Oguchi1型疾病的原因。
