Polymorphism of CGG Repeats in the FRAXE Fragile Site in the Qinba Mountain area Children and Its Association with Intelligence

Abstract

Variations of CGG repeats in the FRAXE fragile site were determined by PCR amplification followed by polyacrylamide gel electrophoresis and sequencing in randomly collected Qinba Mountain Area children whose intelligence level was determined by China-Wechsler Intelligence Scale for Children (C-WISC). Correlations between IQ score and the number of CGG repeats were analyzed. Results indicated a difference in the range of CGG repeats among populations from different regions, but no difference in the distribution of allele frequency in such a population. CGG repeats were not associated with IQ scores in randomly collected subjects (r=0.083, P>0.05), in males and females (r(m)=0.225, r(f)=-0.041, P>0.05), or in subjects with different intelligent levels (F=0.195, P>0.05). It can be inferred that variation in the size of CGG repeats was not associated with intellectual performance in the Qinba Mountain area children.