Leber先天性黑蒙临床与GUCY2D基因突变分析

Clinical analysis and candidate gene mutational screening in children with Leber congenital amaurosis

目的 分析 L eber先天性黑蒙的临床特点及其候选基因变异情况。方法 连续收集分析 2 7例年龄 4m o～ 18a的 L eber先天性黑蒙先证者临床资料。应用 PCR-异源双链- SSCP法分析 GUCY2 D基因外显子 2和 8,寻找可能的变异。结果 2 7例患者均在 2 a以内出现视力差或对光、物体无反应 ,最好视力小于 0 .1。症状年龄 2 1例在 3m o内。 2 7例均有眼球震颤 (其中 15例为眼球扫视运动 )。 2 2例有眼底异常 ,5例眼底未见异常。 3例有家族史并呈常染色体隐性遗传。 ERG锥杆反应重度下降或记录不到波。未发现 GU CY2 D基因突变。结论 L eber先天性黑蒙临床表现多样 ,诊断有赖于 ERG。本组病例可能与GU CY2 D外显子 2。

Objective To analyze the clinical phenotype and to screen for causative mutations in GUCY2D gene in children with Leber's congenital amaurosis (LCA).Methods Clinical data and genomic DNA were collected from 27 patients with LCA. The exons 2 and 8 of the GUCY2D gene were analyzed using PCR heteroduplex SSCP method.Results Visual inattention was noticed in all 27 probands with LCA and the best corrected visual acuity less than 0.1. Symptomatic age in all 27 cases was less than 2 years old, and 21 of the 27 were less than 3 months. Nystagmus was present in all cases in which a searching eye movement was present in 15 cases. Fundus changes were found in 22 cases but a normal fundus was present in 5 cases. Three of the 27 had a family history displayed an autosomal recessive inheritance. ERG cone and rod responses were markedly reduced or non recordable in all cases. Mutation in the exons 2 and 8 of the GUCY2D gene was not detected in these 27 probands.Conclusion Clinical manifestation varied in patients with LCA and the diagnosis of LCA mainly depends on the examination of ERG. Mutation in the exons 2 and 8 of the GUCY2D gene is not responsible for the retinal degeneration in the 27 patients.