Detection of Down Syndrome by Multiplex Fluorescent Polymerase Chain Reaction (การตรวจวินิจฉัยกลุ่มอาการดาวน์ โดยเทคนิค Multiplex Fluorescent Polymerase Chain Reaction)

Down syndrome is the most common chromosome abnormalities. In this study, the objective was to develop a method for detection of Down syndrome by using the multiplex fluorescent polymerase chain reaction (PCR). The method was performed by amplification of STR markers located on chromosome 21 specific for loci D21S11, D21S1411 and D21S1413. The PCR products were analyzed based on the principle of capillary electrophoresis on an automated sequencer. Interpretation of the results could be performed by considering peak patterns in STRs. Normal samples showed two peaks with a peak area ratio of 1:1 or a single peak. Down syndrome samples were characterized by either three peaks, two peaks with a peak area ratio of 2:1 or a single peak. This method was performed in 32 DNA samples of Down syndrome patients and 50 DNA samples of normal subjects. All the results were in accordance with chromosome analysis. These data demonstrate that the technique is accurate, reliable and rapid for the detection of Down syndrome within 24 hours. This method should be useful to support the prevention and control program of Down syndrome. Key words: Down syndrome, multiplex fluorescent PCR, laboratory diagnosis