Mutations in the CHST6 gene in patients with macular corneal dystrophy:: Immunohistochemical evidence of heterogeneity
Mutations in the CHST6 gene in patients with macular corneal dystrophy:: Immunohistochemical evidence of heterogeneity
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DOI：
10.1167/iovs.02-0910
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发表时间：
2003-08-01
影响因子：
4.4
通讯作者：
Kanai, A
中科院分区：
文献类型：
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作者：
Iida-Hasegawa, N;Furuhata, A;Kanai, A
目的。黄斑性角膜营养不良(MCD)是一种常染色体隐性遗传病，可导致严重的视力障碍。编码16q22上N-乙酰氨基葡萄糖6-O-磺基转移酶的糖基转移酶6(CHST6)基因被认为是MCD的致病基因。本研究的目的是鉴定日本MCD患者的CHST6基因突变，并用免疫组织化学方法对其进行评估。方法：对7例MCD患者和45名健康对照进行CHST6基因突变筛查。提取基因组DNA，聚合酶链式反应(PCR)扩增CHST6的开放阅读框(ORF)。对扩增产物进行直接测序和限制性内切酶分析。结果：在CHST6的ORF中发现了3个新的突变(P204Q、R205L和R177H)和两个已报道的突变(R211W和A217T)。P204Q、R205L和R211W是纯合子，R177H和A217T与R211W在另一个等位基因上是杂合子。免疫组织化学显示R205L纯合子角膜对抗KS抗体呈阴性反应，代表I型MCD，R211W纯合子和R211W/A217T复合杂合子角膜与抗体阳性沉积的基质呈阴性或极弱反应，这与以往报道的类型不同。结论两个突变(纯合子R211W和复合杂合子R211W/A217T)在免疫组织化学中属于新的MCD表型。这种异质性可以为MCD的发病机制提供更深入的认识。
PURPOSE. Macular corneal dystrophy (MCD) is an autosomal recessive disorder leading to severe visual impairment. The carbohydrate sulfotransferase 6 (CHST6) gene, which encodes the corneal N-acetylglucosamine 6-O-sulfotransferase on 16q22 has been identified as a causative gene for MCD. The purpose of this study was to identify mutations in CHST6 in Japanese patients with MCD and evaluate them by means of immunohistochemistry.METHODS. CHST6 was screened in 7 patients and 45 healthy control subjects. Genomic DNA was isolated, and the open reading frame (ORF) of CHST6 was amplified by polymerase chain reaction (PCR). PCR products were analyzed by direct sequencing and restriction enzyme digestion. Immunohistochemistry with a monoclonal anti-keratan sulfate (KS) antibody was performed on corneas of four patients from three families.RESULTS. Three novel mutations (P204Q, R205L, and R177H) and two previously reported mutations (R211W and A217T) were identified in the ORF of CHST6. P204Q, R205L, and R211W were found to be homozygous and R177H and A217T compound heterozygous with R211W on another allele. Immunohistochemistry revealed that R205L homozygous cornea had negative reactivity against the anti-KS antibody, representing type I MCD, and that R211W homozygous and R211W/A217T compound heterozygous corneas had negative or very weak reactivity in the stroma with antibody positive deposits, which were distinct from any previously reported types.CONCLUSIONS. Two mutations (homozygoous R211W and compound heterozygous R211W/A217T) should be subclassified immunohistochemically into new phenotypes of MCD. This heterogeneity could provide further insights into the pathogenesis of MCD.