NeuroTherapeutics Research Institute, University of California Davis Medical Center Sacramento, CA, USA.
Front Hum Neurosci. 2011 Jul 14;5:63. doi: 10.3389/fnhum.2011.00063. eCollection 2011.
The high frequency of the fragile X premutation in the general population and its emerging neurocognitive implications highlight the need to investigate the effects of the premutation on lifespan cognitive development. Until recently, cognitive function in fragile X premutation carriers (fXPCs) was presumed to be unaffected by the mutation. Although as a group fXPCs did not differ from healthy controls (HCs), we show that young adult female fXPCs show subtle age- and significant fragile X mental retardation 1 (FMR1) gene mutation-modulated cognitive function as tested by a basic numerical enumeration task. These results indicate that older women with the premutation and fXPCs with greater CGG repeat lengths were at higher risk for difficulties in the deployment of volitional attention required to count 5-8 items, but spared performance when spatial shifts of attention were minimized to subitize a few (1-3). Results from the current study add to a growing body of evidence that suggests the premutation allele is associated with a subtle phenotype and implies that the cognitive demands necessary for counting are less effectively deployed in female fXPCs compared to HCs.
脆性 X 前突变在普通人群中的高频率及其新兴的神经认知意义强调了需要研究前突变对寿命认知发展的影响。直到最近，脆性 X 前突变携带者（fXPC）的认知功能还被认为不受突变的影响。尽管作为一个群体，fXPC 与健康对照组（HC）没有差异，但我们表明，年轻成年女性 fXPC 在基本数字枚举任务中表现出微妙的年龄和明显的脆性 X 智力低下 1 型（FMR1）基因突变调节的认知功能。这些结果表明，具有前突变的老年女性和具有较长 CGG 重复序列的 fXPC 更有可能在需要计数 5-8 项的自愿注意力部署方面存在困难，但当最小化空间注意力转移以亚比计数（1-3）时，表现则不受影响。当前研究的结果增加了越来越多的证据表明，前突变等位基因与微妙的表型有关，并暗示与计数相关的认知需求在女性 fXPC 中比在 HCs 中更有效地部署。
