PURPOSE: Fragile X syndrome is the most common form of hereditary intellectual disability. Detection of the fragile X phenotype in the prepubertal period is very difficult, and early detection might assist in early developmental intervention and reproductive counseling. A pilot study was conducted to establish the feasibility of newborn screening for fragile X syndrome. METHODS: A prospective study was done contacting mothers postdelivery in two hospitals in upstate South Carolina from 2005 to 2006. With their permission, blood samples were obtained from the male infants via heelstick and analyzed. RESULTS: A total of 1,459 newborns were tested, and 5 abnormal results were obtained. The results included one sex chromosome aneuploidy (47, XXY), two premutations, and two full mutations. CONCLUSIONS: Our study establishes the potential feasibility of such a screening process. However, more complete studies assessing a larger population and risk-benefit analyses are necessary before any universal application of this test. Our detection rate for fragile X syndrome (1:730) was inexplicably greater than anticipated but likely represents a chance occurrence among the small number of infants tested.
PURPOSE: Fragile X syndrome is the most common form of hereditary intellectual disability. Detection of the fragile X phenotype in the prepubertal period is very difficult, and early detection might assist in early developmental intervention and reproductive counseling. A pilot study was conducted to establish the feasibility of newborn screening for fragile X syndrome. METHODS: A prospective study was done contacting mothers postdelivery in two hospitals in upstate South Carolina from 2005 to 2006. With their permission, blood samples were obtained from the male infants via heelstick and analyzed. RESULTS: A total of 1,459 newborns were tested, and 5 abnormal results were obtained. The results included one sex chromosome aneuploidy (47, XXY), two premutations, and two full mutations. CONCLUSIONS: Our study establishes the potential feasibility of such a screening process. However, more complete studies assessing a larger population and risk-benefit analyses are necessary before any universal application of this test. Our detection rate for fragile X syndrome (1:730) was inexplicably greater than anticipated but likely represents a chance occurrence among the small number of infants tested.