Distribution of FMR1 and FMR2 alleles in Javanese individuals with developmental disability and confirmation of a specific AGG-interruption pattern in Asian populations

The number of trinucleotide repeats in the 5' untranslated regions of the F MR1 and FMR2 genes determined by PCR in 254 Fragile XA-negative Javanese ma le children with developmental disabilities. The distribution of FMR1 and F MR2 trinucleotide repeat alleles was found to be significantly different in the Indonesian population with developmental disability compared to that i n developmentally disabled populations in North America and Europe (p < 0.0 21). Sequence analysis was performed on the trinucleotide repeat arrays of the 27 individuals with FMR1 alleles in the 'grey zone' (35-54 repeats). A repeat array structure of 9A9A6A9 was found in 16 unrelated with 36 repeats , confirming earlier observations in intellectually normal Japanese. We pro pose that this FMR1 array pattern is specific for Asian populations and tha t Javanese and Japanese populations arose a single progenitor population.