RAPID DETECTION OF SEX CHROMOSOMAL ANEUPLOIDIES BY PCR

In this report we present a method to determine sex chromosomal aneupl oidies by duplex polymerase chain reaction with sufficient precision t o distinguish between one, two and more copies of X and Y sequences. W e coamplified an autosomal gene segment (exon 33 of neurofibromatosis type I gene on chromosome 17) as an internal standard for our sequence of interest (AMXY) on X and Y chromosomes. By using this standard as a reference for two gene copies we could visually estimate the relativ e gene dosage for the X-, and Y-specific AMXY sequences in the DNA sam ple under consideration, We have evaluated this method in normal males and females and in patients with known sex chromosomal aneuploidies a nd have found it to be a reliable and quick tool for detection of nume rical sex chromosomal abnormalities.