Elyakim S, Lerer I, Zlotogora J, Sagi M, Gelman-Kohan Z, Merin S, Abeliovich D
Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel.
Am J Med Genet. 1994 Dec 1;53(4):325-34. doi: 10.1002/ajmg.1320530405.
Linkage analysis of 18 neurofibromatosis type I (NFI) families was performed using intragenic and flanking polymorphic markers. The aims of the analysis were prenatal diagnosis of at-risk fetuses, and of asymptomatic individuals who were relatives of NFI patients. Prenatal diagnosis was performed in 9 pregnancies of 7 families; 5 fetuses were diagnosed as affected. In 6 families with an affected spouse, the request was to identify informative polymorphisms to be used in future pregnancies. Presymptomatic diagnosis was performed in 4 families. One individual, a brother of an NFI patient, was found to have Lisch nodules as the only NFI symptom. Linkage analysis indicated that if this person is a carrier of the NFI gene, he must be a product of intragenic crossover. In 2 individuals with a new NFI mutation, the origin of the NFI-bearing chromosomes was paternal. The same observation was noted by others. A summary of published cases shows that some 90% of the NFI-bearing chromosomes of patients with new mutations were of paternal origin. We therefore suggest that for the purpose of prenatal diagnosis in carriers of NFI new (and unidentified) mutations, the paternal chromosome will be considered as the NFI-bearing chromosome.
使用基因内和侧翼多态性标记对18个I型神经纤维瘤病（NFI）家族进行了连锁分析。分析的目的是对高危胎儿以及NFI患者的无症状亲属进行产前诊断。对7个家族的9次妊娠进行了产前诊断；5例胎儿被诊断为患病。在6个配偶患病的家族中，需求是鉴定可用于未来妊娠的信息性多态性。对4个家族进行了症状前诊断。一名个体，即一名NFI患者的兄弟，被发现仅以Lisch结节作为NFI症状。连锁分析表明，如果此人是NFI基因的携带者，他必定是基因内交叉的产物。在2名有新的NFI突变的个体中，携带NFI的染色体起源于父方。其他人也有同样的观察结果。已发表病例的总结表明，新突变患者中约90%携带NFI的染色体起源于父方。因此，我们建议，为了对NFI新（且未明确）突变携带者进行产前诊断，父方染色体将被视为携带NFI的染色体。
