自然流产一家系中15p+染色体的分子细胞遗传学研究

MOLECULAR CYTOGENETIC STUDY ON A 15p+VARIANT IN A FAMILY WITH SPONTANEOUS ABORTIONS

通过对一自然流产家系中先证者母女染色体的分子细胞遗传学研究,发现都有一个短臂明显增长的15号染色体(15p+),在p+上有数目倍增、体积增大的核仁组成区(NOR)。应用7.3kb的rRNA基因探针对15p+染色体进行原位杂交,证实p+部分系NOR核糖体基因(rRNA)高度重复的结果,从而排除了Y或其它染色体参与形成p+的可能性。

A 27-year-old proband with spontaneous abortions was found carrying a marker chromosome 15p+. By means of cytogenetic analysis, bigger dNORs were observed on the short arm of the marker. Using a 7.3kb fragment of 18S and 28S rDNA as a probe and by chromosomal in situ hybridization, it was demonstrated that the p + was the result of the duplication of NOR and rDNA on this chromosome. This finding suggested that the amplified rDNA on the 15p+ be active and have relation to the clinical feature of the proband.