Sutherland G R
Am J Hum Genet. 1982 May;34(3):452-8.
The incidence of the autosomal folic-acid-sensitive fragile sites in 524 institutionalized retardates (.0095) was found to be significantly higher than in 1,019 unselected neonates (.00098), suggesting that heterozygosity for these fragile sites may not be as harmless as previously thought. When one of the parents of an index case was found to carry the fragile site, that parent was always the mother. The fragile site at Xq27 was not found among the neonates studied, but was present in 1.6% of the institutionalized retarded males examined; if this fragile site occurs in normal males, then it does so rarely. Further cytogenetic studies of fragile sites are required on both normal and abnormal populations.
在524名收容机构中的智力迟钝者身上发现常染色体叶酸敏感脆性位点的发生率(0.0095)显著高于1019名未经筛选的新生儿(0.00098),这表明这些脆性位点的杂合性可能不像之前认为的那么无害。当一个索引病例的父母一方被发现携带脆性位点时,该方总是母亲。在所研究的新生儿中未发现Xq27处的脆性位点,但在1.6%接受检查的收容机构中的智力迟钝男性身上存在;如果这种脆性位点出现在正常男性身上,那么也是极为罕见的。需要对正常和异常人群进行关于脆性位点的进一步细胞遗传学研究。