Izumi T, Nagaoka U, Saito T, Takamatsu J, Saito H, Ichinose A
Department of Molecular Patho-Biochemistry, Yamagata University School of Medicine, Japan.
Thromb Haemost. 1998 Mar;79(3):479-85.
In order to explore molecular mechanisms for factor XIII deficiency, a patient (Nagoya I) was examined at the DNA and RNA levels. Nucleotide sequence analysis of the patient's DNA amplified by PCR revealed that he had a 20 bp deletion at the boundary of exon I/intron A, and an insertion of T in the invariant GT dinucleotide at the splicing donor site of exon IV/intron D. The presence of these heterozygous mutations was confirmed by restriction digestion of the amplified fragments of the proband and his parents. RT-PCR analysis demonstrated that only one kind of mRNA without exon IV was detected in Nagoya I, although its level was greatly reduced to less than 5% of normal. The other detective allele of the A subunit gene containing the 20 bp deletion was not detected. Thus, both mutations impaired normal processing of mRNA for the A subunit, resulting in his severe factor XIII deficiency.
为了探究因子ⅩⅢ缺乏的分子机制，对一名患者（名古屋Ⅰ型）进行了DNA和RNA水平的检测。通过PCR扩增患者的DNA并进行核苷酸序列分析，结果显示他在第Ⅰ外显子/内含子A的边界处有一个20bp的缺失，并且在第Ⅳ外显子/内含子D的剪接供体位点的保守GT二核苷酸处插入了一个T。通过对先证者及其父母扩增片段进行限制性酶切，证实了这些杂合突变的存在。逆转录聚合酶链反应（RT-PCR）分析表明，在名古屋Ⅰ型患者中仅检测到一种不含第Ⅳ外显子的mRNA，尽管其水平大幅降低至正常水平的5%以下。含有20bp缺失的A亚基基因的另一个检测到的等位基因未被检测到。因此，这两种突变均损害了A亚基mRNA的正常加工过程，导致他严重缺乏因子ⅩⅢ。
