Gu Jing-zhi, Qi Yan-hua, Lin Hui, Li Xiang, Wang Jin, Meng Wei-min, Su Hong
Department of Ophthalmology, the Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China.
Zhonghua Yan Ke Za Zhi. 2006 Oct;42(10):913-7.
To identify genetic defects associated with autosomal dominant congenital golden crystal nuclear cataract (ADCC) in a Chinese pedigree of northern China.
Clinical data were collected and the lens changes of the affected members in this family were recorded by slit lamp photography. Genomic DNA was obtained from blood leucocytes. Linkage analyses was conducted using polymorphisms of 21 microsatellite markers and mutational analyses of candidate genes was studied by direct sequencing.
The maximum LOD score (1.505 at recombination fraction theta = 0.00) was obtained at markers D2S1782, D2S1384 and D2S1385 near the gamma-crystallin gene (CRYG) cluster within 2q33 - q35. Sequencing analysis of the coding regions of the CRYGA. B, C, and D genes showed that the there was a heterozygous C-->A transversion at position 109 (R36S) in exon 2 of CRYGD gene, which was co-segregated with the affected members.
R36S mutation in CRYGD gene results in an ADCC phenotype that is different from previous reports. This finding indicates that the presence of phenotypic heterogeneity of cataract, especially in different races. This is the first report of congenital cataract caused by R36S mutation in CRYGD gene.
在中国北方一个常染色体显性先天性金色晶状体核性白内障（ADCC）的中国家系中鉴定相关基因缺陷。
收集临床资料，通过裂隙灯照相记录该家族中患病成员的晶状体变化。从血液白细胞中获取基因组DNA。使用21个微卫星标记的多态性进行连锁分析，并通过直接测序研究候选基因的突变分析。
在2q33 - q35内靠近γ-晶状体蛋白基因（CRYG）簇的标记D2S1782、D2S1384和D2S1385处获得最大LOD分数（重组分数θ = 0.00时为1.505）。对CRYGA、B、C和D基因编码区的测序分析表明，CRYGD基因外显子2中第109位（R36S）存在杂合的C→A颠换，且与患病成员共分离。
CRYGD基因中的R36S突变导致了一种与先前报道不同的ADCC表型。这一发现表明白内障存在表型异质性，尤其是在不同种族中。这是CRYGD基因中R36S突变导致先天性白内障的首次报道。
