Multiplex ligation-dependent probe amplification (MLPA)

Multiplex ligation-dependent probe amplification (MLPA) is a DNA assay that detects copy-number changes and small deletions/duplications across multiple genomic targets simultaneously. Probe pairs hybridize adjacent to each target, are ligated, then amplified with universal primers; fragment sizes are separated and quantified by electrophoresis. Peak heights indicate relative copy number. MLPA is rapid and sensitive for exon- or gene-level dosage changes but won’t detect balanced rearrangements or single-base changes.

A positive MLPA test indicates a detected copy-number change—such as a deletion or duplication—within the DNA regions targeted by the assay. It suggests a genetic abnormality that may explain a clinical condition or disease risk. Results usually require confirmation (repeat testing or alternative methods) and interpretation by a clinical geneticist or genetic counselor, who will correlate findings with symptoms and family history.

MS-MLPA combines probe hybridization, ligation and PCR to assess DNA copy number and CpG methylation. Probes hybridize adjacent to target sequences and are ligated only if bound. A methylation‑sensitive restriction enzyme digests unmethylated sites before PCR; methylated sites are protected and yield amplifiable ligated probes. Relative peak heights after fragment analysis indicate methylation status and gene dosage.

MLPA (multiplex ligation‑dependent probe amplification) is a molecular genetic test that analyses DNA for deletions, duplications and copy‑number changes. It’s performed on extracted DNA — commonly obtained from a peripheral blood (EDTA) sample — but can also use saliva, buccal cells, tissue, or prenatal samples. So while often done on blood, MLPA is a DNA lab test, not a routine blood chemistry test.

MLPA shows relative probe peak heights compared with controls. Ratios near 1.0 are normal; ~0.5 suggests a heterozygous deletion; ~1.5 indicates a duplication; near 0 implies a homozygous deletion. Check internal controls, assay quality and possible mosaicism. Single‑exon findings often need confirmation by another method. Interpret results with clinical context and seek genetic counselling and confirmatory testing for suspected pathogenic changes.

Costs for MLPA (Multiplex Ligation-dependent Probe Amplification) vary by country and provider. In private diagnostic labs it commonly ranges from about $100–$500 per test; in India typical prices are roughly ₹3,000–₹15,000. Public healthcare systems usually provide MLPA when clinically indicated without direct patient charge. Additional fees for interpretation, repeat testing or panel expansions may apply.