Sippel K C, DeStefano J D, Berson E L, Dryja T P
Ocular Molecular Genetics Institute, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, USA.
Invest Ophthalmol Vis Sci. 1998 Mar;39(3):665-70.
To establish the DNA sequence of the coding regions of the human arrestin locus and to determine whether defects in this sequence are present among patients with retinitis pigmentosa (RP) or types of stationary night blindness in addition to Oguchi disease.
The human genomic locus encoding arrestin was cloned in bacteriophage and P1 vectors. The sequence of the intron DNA flanking each exon was determined from these clones. Single-strand conformation polymorphism analysis and direct genomic sequencing techniques were used to screen 272 unrelated patients, comprising 177 patients with autosomal dominant RP, 85 with recessive RP, and 10 with stationary night blindness.
The arrestin gene is divided into 16 exons ranging in size from 10 bp to 194 bp, with the open reading frame spanning exons 2 through 16. The authors identified several discrepancies between the genomic sequence the authors obtained and the previously published cDNA and genomic sequences. In the set of patients with dominant RP, the authors found one of three heterozygous missense changes (Arg84Cys, Thr125Met, and Val378Ile) in each of four unrelated patients; none of these changes cosegregated with disease in the respective families. In the set of patients with recessive RP, the authors found one of two heterozygous missense changes in each of two unrelated patients with recessive RP (Pro364Leu and Arg384Cys). One of the patients was the offspring of a consanguineous marriage; because the Arg384Cys change in him was heterozygous, it is unlikely to have been the cause of his RP. Cosegregation studies could not be performed on the patient with the Pro364Leu change. The authors confirmed the existence of two previously described polymorphisms (Ile76Val and a multiallelic polymorphism at codon 403), and the authors identified several silent polymorphisms and rare sequence variants. No sequence changes, other than polymorphic changes also found in some patients with RP, were identified in the patients with stationary night blindness.
We found no evidence that mutations in arrestin are a cause of RP or stationary night blindness other than Oguchi disease. According to the genomic sequence obtained, a region in exon 8 that has been postulated to represent the site of interaction between arrestin and rhodopsin is 100% conserved between humans and all other mammals studied to date.
确定人类抑制蛋白基因座编码区的DNA序列，并确定视网膜色素变性（RP）患者或除小宫病之外的静止性夜盲症患者中该序列是否存在缺陷。
将编码抑制蛋白的人类基因组基因座克隆到噬菌体和P1载体中。从这些克隆中确定每个外显子侧翼的内含子DNA序列。使用单链构象多态性分析和直接基因组测序技术对272名无亲缘关系的患者进行筛查，其中包括177名常染色体显性RP患者、85名隐性RP患者和10名静止性夜盲症患者。
抑制蛋白基因分为16个外显子，大小从10 bp到194 bp不等，开放阅读框跨越外显子2至16。作者发现他们获得的基因组序列与先前发表的cDNA和基因组序列之间存在一些差异。在显性RP患者组中，作者在4名无亲缘关系的患者中分别发现了三种杂合错义变化（Arg84Cys、Thr125Met和Val378Ile）之一；在各自家族中，这些变化均未与疾病共分离。在隐性RP患者组中，作者在两名无亲缘关系的隐性RP患者中分别发现了两种杂合错义变化（Pro364Leu和Arg384Cys）之一。其中一名患者是近亲结婚的后代；由于他的Arg384Cys变化是杂合的，因此不太可能是其RP的病因。对于发生Pro364Leu变化的患者无法进行共分离研究。作者证实了两个先前描述的多态性（Ile76Val和密码子403处的多等位基因多态性）的存在，并且作者鉴定出了几个沉默多态性和罕见序列变异。在静止性夜盲症患者中，除了在一些RP患者中也发现的多态性变化外，未发现其他序列变化。
我们没有发现证据表明抑制蛋白突变是除小宫病之外的RP或静止性夜盲症的病因。根据获得的基因组序列，外显子8中一个被假定为代表抑制蛋白与视紫红质之间相互作用位点的区域在人类和迄今为止研究的所有其他哺乳动物之间100%保守。
