Identification of sterol 27 hydroxylase gene mutations in CTX patients

CTX患者甾醇27羟化酶基因突变的鉴定

• 批准号: 07457034
• 负责人: SEYAMA Yousuke
• 金额: $ 5.12万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07457034/
• 关键词: cerebrotendinous xanthomatosis; cholesterol; cholestanol; sterol 27-hydroxylase gene; point mutation; transfection; 遺伝子解析; ステロール27位水酸化酵素

Cerebrotendinous xathomatosis (CTX), an autosomal recessive lipid-storage hereditary disorder, is caused by mutations in the sterol 27-hydroxylase gene (CYP27). A 24-year-old female Japanese CTX patient and her parents were studied for a CYP27 mutation. Sterol 27-hydroxylase activity in fibroblasts derived from the patient was undetectable, while the activities in fibroblasts from her mother and father were 54% and 41% of the normal level, respectively. Direct sequence analysis showed a missense mutation of A for G substitution in the CYP27 gene at codon 362 (CGT 362Arg to CAT 362His) with a homozygous pattern in the patient, and a heterozygous pattern in the parents. The mutation, which eliminates a normal Hga I endonuclease site at position 1195 of the cDNA and is located at the adrenodoxin binding region of the gene, is most probably responsible for the decreased sterol 27-hydroxylase activity in this Japanese CTX family.Other three Japanese CTX patients from two unrelated families were also studied genetically. By DNA sequence analysis a novel mutation of A for G substitution at amino acid position 372 (CGG 372Arg to CAG 372Gln) was identified in one of the CTX families. The mutation was also found in two patients from the other family, with a compound heterozygous pattern of A for G substitution at amino acid position 441 (CGG 441Arg to CAG441Gln). The latter mutation was the same as previously reported by our group (J.Lipid Res. 1994,35 : 1031-1039). As the two mutations changed the restriction enzyme sites, rapid screening methods were developed for the detection of the carriers. Transfection of the two mutant cDNAs into COS cells resulted in markedly reduced sterol 27-hydroxylase activity. These results indicate that the three mutations are responsible for the deficiency of the sterol 27-hydroxylase activity in these patients.

脑腱xathomatosis（CTX）是一种常染色体隐性遗传性脂质沉积症，由固醇27-羟化酶基因（CYP 27）突变引起。研究了一名24岁的日本女性CTX患者及其父母的CYP 27突变。来自患者的成纤维细胞中的甾醇27-羟化酶活性检测不到，而来自其母亲和父亲的成纤维细胞中的活性分别为正常水平的54%和41%。直接序列分析显示CYP 27基因第362位密码子发生错义突变（CGT 362 Arg变为CAT 362 His），患者为纯合型，父母为杂合型。该突变消除了cDNA第1195位正常的Hga Ⅰ内切酶位点，位于该基因的肾上腺素结合区，很可能是导致该日本CTX家系甾醇27-羟化酶活性降低的原因。通过DNA序列分析，在一个CTX家族中发现了一个新的突变，即第372位氨基酸由A替换为G（CGG 372 Arg变为CAG 372 Gln）。另一家系的2例患者也发现了该突变，其复合杂合模式为441位氨基酸A替换为G（CGG 441 Arg替换为CAG 441 Gln）。后一种突变与我们小组以前报道的相同（J.LipidRes.1994，35：1031-1039）.由于这两个突变改变了限制性酶切位点，因此发展了快速筛查方法用于携带者的检测。将这两个突变体cDNA转染COS细胞，导致甾醇27-羟化酶活性显著降低。这些结果表明，这三个突变是负责在这些患者中的甾醇27-羟化酶活性的缺陷。

项目成果

脊山洋右: "フィトステロール血症" 現代医療. 28. 299-301 (1996)

Yosuke Seyama：“植物甾醇血症”现代医学 28. 299-301 (1996)。

Koichiro Kuwabara, Seiji Hitoshi, Nobuyuki Nukina, Kenji Ishii, Toshimitsu Momose, Shunichiro Kubota, Yousuke Seyama, and Ichiro Kanazawa: "PET analysis of a case of cerebrotendinous xanthomatosis presenting hemiparkinsonism" J.Neurol.Sci.138. 145-149 (19

Koichiro Kuwabara、Seiji Hitoshi、Nobuyuki Nukina、Kenji Ishii、Toshimitsu Momose、Shunichiro Kubota、Yousuke Seyama 和 Ichiro Kanazawa：“一例表现为偏帕金森病的脑腱黄瘤病病例的 PET 分析”J.Neurol.Sci.138。