Fragile X syndrome is characterized almost always by moderate intellectual disability in males and mild intellectual disability in females as well as characteristic facial features, joint laxity, and behavioral problems.

This laboratory uses the technology of Asuragen PCR, which is more sensitive and accurate than Southern blot. It is capable of detecting a range of variations including normal alleles and permutations that start with ~55 repeats, up to full mutations of more than 1,000 CGG repeats. Samples found to be potentially abnormal are retested with methylation PCR to confirm repeat length and also to determine methylation status of the repeat region.