What type of changes does MLPA primarily measure?

Multiplex Ligation-dependent Probe Amplification (MLPA) is primarily designed to measure quantitative changes in DNA sequences. This method enables the simultaneous amplification and quantification of multiple target DNA regions, making it particularly useful for detecting copy number variations (CNVs) such as duplications or deletions in genomic DNA.

By using specific probes that hybridize to target sequences, MLPA allows for the assessment of the relative amounts of DNA at specific loci, thereby revealing whether these sequences are present in normal, increased, or decreased quantities. This quantitative approach is especially valuable in clinical diagnostics and genetic research, where understanding changes in gene dosage can correlate with various genetic disorders or conditions.

In contrast, measuring the quality of nucleic acids focuses more on the integrity or purity of the DNA rather than the quantity. Structural variations, while related to changes in the genome, encompass a broader scope beyond just quantitative alterations and include events such as translocations or inversions that MLPA does not primarily focus on. Functional alterations pertain to how genes are expressed and regulated rather than the specific quantitative assessment of DNA sequence copy numbers. Thus, the essence of MLPA's capability lies in its ability to detect and provide information regarding quantitative changes in DNA.