What is Multiplex Ligation Dependent Probe Amplification (MLPA)?
Multiplex Ligation Dependent Probe Amplification (MLPA) is a sensitive, high-throughput technique used for detecting
copy number variations (CNVs) in DNA sequences. It is particularly useful in identifying deletions and duplications, which are common in various genetic disorders. The technique relies on the ligation of specific probes to target sequences, followed by amplification and quantification, allowing for the precise measurement of DNA copy numbers.
High Sensitivity and Specificity: It can detect even small deletions and duplications with high precision.
Efficiency: The technique allows for the simultaneous analysis of multiple targets in a single reaction.
Cost-Effective: Compared to other methods like
whole genome sequencing, MLPA is more affordable and quicker, making it suitable for routine clinical practice.
Versatility: MLPA can be adapted to analyze various types of genetic material, including
genomic DNA and RNA.
Resolution: MLPA cannot detect single nucleotide polymorphisms (SNPs) or small insertions and deletions (
indels).
Interpretation: The results can sometimes be challenging to interpret, especially in cases of complex rearrangements.
Coverage: MLPA is limited to the specific probes used in the assay, meaning it cannot provide a comprehensive analysis of the entire genome.
When is MLPA Recommended?
MLPA is recommended in various clinical scenarios, particularly when there is a suspicion of a genetic disorder that involves copy number variations. Some common indications include:
Unexplained developmental delays or intellectual disability.
Congenital abnormalities suggestive of a genetic syndrome.
Family history of genetic disorders like DMD or SMA.
Newborn screening for specific genetic conditions.
DNA Extraction: Genomic DNA is extracted from the patient's sample.
Probe Hybridization: MLPA probes are hybridized to the target sequences in the DNA.
Ligation: The hybridized probes are ligated to form a continuous sequence.
Amplification: The ligated products are amplified using PCR.
Detection: The amplified products are separated and quantified, usually by capillary electrophoresis.
Are There Any Risks or Side Effects?
MLPA is a non-invasive test with no direct risks or side effects to the patient. The primary risk lies in the potential for misinterpretation of results, which underscores the importance of having the test performed and interpreted by experienced professionals.
Conclusion
In the field of pediatrics, Multiplex Ligation Dependent Probe Amplification (MLPA) is a powerful tool for diagnosing and understanding genetic disorders. Its high sensitivity, specificity, and efficiency make it invaluable for identifying copy number variations associated with various pediatric conditions. While it does have some limitations, the benefits of MLPA in providing accurate and timely genetic diagnoses far outweigh the drawbacks, making it a cornerstone in pediatric genetic testing.
