MLPA for prenatal diagnosis of commonly occurring aneuploidies

Multiplex ligation-dependent probe amplification (MLPA) is a new method to determine the copy number of up to 45 genomic DNA sequences in a single multiplex polymerase chain reaction (PCR)-based reaction. In contrast to standard multiplex PCR, only one pair of PCR primers is used. MLPA reactions with currently commercial available kits result in very reproducible gel patterns with fragments of 130 to 480 bp that can be analyzed by sequence type electrophoresis. Comparison of this gel pattern to that obtained from a control sample indicates which sequences show an aberrant copy number.