Atanassov N, Markova V
Department of Clinical Laboratory, Higher Medical Institute, Plovdiv, Bulgaria.
Folia Med (Plovdiv). 1998;40(3):11-3.
The first case of DNA-confirmed Friedreich's ataxia in Bulgaria is presented. The results from the DNA studies of the index patient revealed two alleles with an expansion between 500 and 1500 repeats of the GAA trinucleotide in the first intron of the X25 gene. The parents had one normal allele with 7-22 repeats and one allele with a similar expansion to that of the patient in the first intron of the X25 gene. These results confirm the homozygous mode of transmission of the abnormal alleles (with an expansion of the GAA trinucleotide in the first intron of the X25 gene) from the two normal heterozygous parents to their affected offspring.
本文报道了保加利亚首例经DNA确诊的弗里德赖希共济失调病例。对索引患者的DNA研究结果显示，在X25基因的第一个内含子中，有两个等位基因存在GAA三核苷酸500至1500次重复的扩增。其父母一方有一个正常等位基因，重复次数为7 - 22次，另一方在X25基因的第一个内含子中有一个与患者类似扩增的等位基因。这些结果证实了异常等位基因（X25基因第一个内含子中的GAA三核苷酸发生扩增）从两个正常杂合子父母向其患病后代的纯合子遗传模式。
