MLPA is primarily a method that identifies deletions/duplications and is not a suitable method to detect unknown point mutations, but is suitable for the detection of known point mutations.
Probes can be designed either to detect the reference (wild type) sequence or the SNP/point mutation sequence of interest. MLPA probes to detect known point mutations are designed so that the ligation site is located directly at the site of the point mutation. Ligation will then only occur when the DNA sequence is a perfect complement to the designed probe, whether this is the reference or SNP/point mutation sequence. Only successfully ligated probes will be amplified, which gives the probes their specificity.