摘要
为了探讨中国遗传性高铁血红蛋白血症患者的基因突变类型和建立相应的基因诊断方法，从已发现的１例Ⅰ型患者的外周血白细胞中提取ＲＮＡ，应用反转录ＰＣＲ法分析了Ｃｙｔｂ５ＲｃＤＮＡ的全部编码序列的９２１ｂｐ片段。结果显示：Ｃｙｔｂ５ＲｃＤＮＡ基因的第５７位密码子存在有Ａｒｇ→Ｇｌｎ（ＣＧＧ→ＣＡＧ）的错义突变。针对这一突变，用套式ＰＣＲ的方法对已有的３个家系共６名患者进行了基因诊断。结果表明其中两个家系的患者均有此位点的突变，５名患者３名为纯合子，２名为杂合子；而另一家系的患者未检测到，推测可能存在有其它突变类型。提示中国人遗传性高铁血红蛋白血症患者致病的分子基础，并建立了相应的基因诊断方法。
To elucidate the molecular mechanisms and set up the method of gene diagnosis in Chinses patients with hereditary methemoglobinemia, we isolated RNA from the peripheral leukocytes of the propositus and synthesized cDNA using RT PCR, then sequenced the coding regions of Cytb 5R cDNA. The results indicated only one notable base change, a guanineto adenine transition in exon 3 at the second position of condon 57, and this nucleotide substitution caused an amino acid change from arginine to glutanine. Further on this mutation site, we analysed genomic DNA of methemoglobinemic patients from three different hereditary mithemoglobinemic pedigrees, using Nested PCR. The results revealed that two pedigrees had CGG→CAG transition at condon 57 but the other pedigree did not have it. We have alse provided evidence that this is not a polymorphism but a mutation that is likely causative of the disease phenotype. Probable machnisms of enzyme deficiency caused by this mutation were discussed.
出处
《中华医学遗传学杂志》
CAS
CSCD
北大核心
1997年第5期281-284,共4页
Chinese Journal of Medical Genetics
基金
全军八五重点课题
关键词
HM
血红蛋白血症
遗传性
NADH
基因诊断
Hereditary methemoglobinemia
Cytochrome b 5 reductase
Reversal transition polymerase chain reaction
Gene diagnosis
