Schreiber W E, Fong F, Jamani A
Division of Clinical Chemistry, Vancouver General Hospital, British Columbia, Canada.
Clin Chem. 1994 Sep;40(9):1744-8.
Analysis for mutations in the porphobilinogen deaminase gene offers a more definitive diagnosis of acute intermittent porphyria (AIP) than do conventional biochemical tests. We used single-strand conformation polymorphism analysis followed by direct sequencing to identify a new G-->A mutation at the last position of intron 7 in a patient with AIP. The mutation disrupts the invariant AG dinucleotide at the 3' splice acceptor site and therefore interferes with mRNA processing. To identify other individuals who inherited this mutation, we analyzed five hairs with intact roots collected by each participating family member and sent to us by mail. DNA was extracted from the hair roots and amplified by the polymerase chain reaction. The amplified products were digested with the restriction enzyme BsaJI to confirm the presence or absence of the mutation. All six family members who were known to have AIP tested positive, as did three members who had not been previously diagnosed. Hair roots provide a convenient, accessible, and economical alternative to blood as a source of DNA for molecular diagnostic testing.
与传统生化检测相比，对胆色素原脱氨酶基因进行突变分析可为急性间歇性卟啉症（AIP）提供更确切的诊断。我们采用单链构象多态性分析并结合直接测序，在一名AIP患者中鉴定出内含子7最后一位的一个新的G→A突变。该突变破坏了3'剪接受体位点的保守AG二核苷酸，从而干扰了mRNA加工。为了识别其他遗传了此突变的个体，我们分析了每个参与的家庭成员收集并邮寄给我们的五根带有完整根部的毛发。从发根中提取DNA，并通过聚合酶链反应进行扩增。用限制性内切酶BsaJI消化扩增产物，以确认突变的存在与否。所有已知患有AIP的六名家庭成员检测呈阳性，三名先前未被诊断出的成员也是如此。作为分子诊断检测的DNA来源，发根为血液提供了一种方便、易获取且经济的替代方案。
