低智儿童常染色体脆性位点的研究

Study on the incidence of chromosome fragility in mental retardation.

本文通过对７５例正常儿童智力低下儿童的外周血淋巴细胞常染色体脆性位点的研究，结果表明：智力低下儿童常染色体脆性位点频率明显高于正常对照组（Ｐ＜０．０５）；轻度、中度和重度智力低下儿童的脆性位点频率之间无显著差异（Ｐ＞００５）。说明智低儿童存在染色体不稳定的遗传基础，而这种染色体不稳定性与智力低下的程度无关。

The incidence and frequency distribution of the folate sensitive fragile sites expression were studied in chromosomes from peripheral blood lymphocyte cultures in 75 cases of mental retardation (MR) and mentally normal children (MN).The results showed that the incidence of fragile sites in MR was higher than MN ( P <0.05),that there was no significant difference among lower.mild and heavy MR.Our results suggests that there was chromosomes instability of MR children.But the chromosomes instability was no relationship with the degree of MR.