Fang L J, Vidaud D, Vidaud M, Thirion J P
Département de Microbiologie et d'Infectiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Québec J1H 5N4, Canada.
Hum Mutat. 2001 Dec;18(6):549-50. doi: 10.1002/humu.1241.
We studied 20 unrelated NF1 patients by Southern blots with seven cDNA probes and loss of heterozygosity (LOH) analysis with four intragenic microsatellites (IVS26-2.3, IVS27AC28.4, IVS27AC33.1, and IVS38GT53.0). Four novel large deletions (178, 184, 236, and 237) have been identified and characterized. The breakpoint of deletion 178 was located in between exons 23-2 and 27b and the sequences downstream of the breakpoint were deleted. For deletion 184, the breakpoint was in between exons 27b and 29, and the region upstream of the breakpoint was deleted. With deletion 236, the breakpoint was in between exons 14 and 18 and the region downstream of the breakpoint was deleted. The breakpoint of deletion 237 was in between exons 38 and 45 and the sequences upstream of the breakpoint were deleted. These deletions were distributed randomly across the NF1 gene and no deletion hot spot was found. Our study suggests that the combination of analyses of loss of heterozygosity, southern blotting and southern blot densitometry can be used as a powerful method to detect large deletions, especially when family record is not available or the patient is a sporadic case.
我们使用7种cDNA探针通过Southern印迹法以及利用4个基因内微卫星（IVS26 - 2.3、IVS27AC28.4、IVS27AC33.1和IVS38GT53.0）进行杂合性缺失（LOH）分析，对20名无亲缘关系的神经纤维瘤病1型（NF1）患者进行了研究。已鉴定并表征了4种新的大片段缺失（178、184、236和237）。缺失178的断点位于外显子23 - 2和27b之间，断点下游的序列被删除。对于缺失184，断点在外显子27b和29之间，断点上游的区域被删除。对于缺失236，断点在外显子14和18之间，断点下游的区域被删除。缺失237的断点在外显子38和45之间，断点上游的序列被删除。这些缺失随机分布在NF1基因上，未发现缺失热点。我们的研究表明，杂合性缺失分析、Southern印迹法和Southern印迹密度测定法相结合可作为检测大片段缺失的有力方法，尤其是在没有家族记录或患者为散发病例的情况下。
