Haan E A, Mulley J C, Gedeon A K, Sheffield L J, Sutherland G R
Adelaide Children's Hospital, North Adelaide, SA 5006.
Med J Aust. 1988 Sep 19;149(6):326-9. doi: 10.5694/j.1326-5377.1988.tb120637.x.
A family in which the gene for myotonic dystrophy is segregating was tested with a DNA probe to the apolipoprotein-C2 (APOC2) gene. The APOC2 gene is linked closely to the myotonic dystrophy (DM) gene and can be used as a marker to follow the transmission of the DM gene within families. Results from DNA-marker studies were combined with information from clinical, ophthalmological and electromyographic examinations, with age-dependent penetrance and a recombinant frequency of 4% between the genes for myotonic dystrophy and apolipoprotein C2 being taken into account. The chance that an individual had inherited the gene for myotonic dystrophy was determined by means of the computer program, LINKAGE. This analysis altered dramatically the assessed risk that certain individuals in the family were carrying the DM gene. For four individuals in the family, the previous risks of 50% for each member were reduced to 0.9%, 0.9% and 0.2%, respectively, in three cases and increased to 91% in the fourth case. The importance of a complete clinical evaluation of potential gene carriers who donate blood for a DNA-linkage study is stressed.
一个携带有强直性肌营养不良基因的家族接受了载脂蛋白C2（APOC2）基因的DNA探针检测。APOC2基因与强直性肌营养不良（DM）基因紧密连锁，可作为追踪DM基因在家族中传递的标记。DNA标记研究结果与临床、眼科和肌电图检查信息相结合，同时考虑年龄依赖性外显率以及强直性肌营养不良基因与载脂蛋白C2基因之间4%的重组频率。利用计算机程序LINKAGE确定个体遗传强直性肌营养不良基因的概率。这一分析显著改变了对该家族中某些个体携带DM基因风险的评估。对于家族中的四名个体，之前每位成员50%的风险在三个案例中分别降至0.9%、0.9%和0.2%，而在第四个案例中则升至91%。强调了对为DNA连锁研究献血的潜在基因携带者进行全面临床评估的重要性。
