Non-invasive screening of fragile X syndrome A using urine and hair roots.

The diagnosis of fragile X A syndrome (FRAXA) during childhood depends largely on DNA-based diagnostic tests due to the lack of the specific clinical features. To determine a non-invasive screening method for fragile X syndrome, we studied the method of DNA-based diagnosis using urine or hair roots instead of routinely used peripheral blood cells. The amplification of repeat-containing alleles of FMR-1 by PCR using Pfu polymerase was applied on DNA extracted from urine sediments or hair roots of 50 and 28 normal individuals, respectively. Consistent amplification of repeat-containing DNA fragments of normal size to ethidium-visible quantities were obtained in 92% (46/50) of urine samples and 100% (28/28) of hair roots. No bands of normal size or abnormal or artificial smears were detected in two male FRAXA patients. No female samples were examined in the present study because the separation of two alleles was unsatisfactory on agarose gels with DNA from blood samples. Our results indicate that the use of hair roots in a DNA-based test constitutes a rapid, simple and less-invasive screen to diagnose males with FRAXA.