Related Experiment Video
Updated: Aug 19, 2026
Detection and Monitoring of Tumor Associated Circulating DNA in Patient Biofluids
Published on: June 8, 2019
Effectiveness of multiplex ligation-dependent probe amplification assay used for detecting deletion of Prader-Willi
Hong Shao1, Va Lip, Bai-lin Wu
1Department of Laboratory Medicine, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Insights
Multiplex ligation-dependent probe amplification (MLPA) effectively detects deletions in Prader-Willi syndrome (PWS) patients. This cost-effective genetic testing method shows high accuracy, aiding in PWS diagnosis.
Area of Science:
- Genetics
- Molecular Biology
- Pediatrics
Background:
- Prader-Willi syndrome (PWS) presents with hypotonia and feeding issues in infancy, progressing to obesity.
- Genetic testing is crucial for PWS diagnosis due to variable clinical presentations.
- Most PWS cases involve abnormalities in the 15q11.2-q12 region, including deletions, uniparental disomy, or imprinting center mutations.
Purpose of the Study:
- To evaluate Multiplex Ligation-dependent Probe Amplification (MLPA) as a diagnostic tool for Prader-Willi syndrome (PWS).
- To assess the cost-effectiveness and efficiency of MLPA compared to existing genetic testing methods for PWS.
Main Methods:
- MLPA, a novel, cost-effective technique for relative gene quantification, was employed.
- MLPA was used to detect genomic deletions in patients suspected of having PWS.
- Results were confirmed using Fluorescence In Situ Hybridization (FISH) and DNA methylation analysis.
Main Results:
- MLPA identified deletions in 6 out of 20 patients referred for PWS genetic diagnosis.
- MLPA results demonstrated 100% concordance with FISH and DNA methylation analysis.
- MLPA proved to be a sensitive and specific method for deletion detection in PWS.
Conclusions:
- MLPA offers high sensitivity and specificity for detecting deletions in PWS, comparable to FISH and Southern blot.
- Further development of a comprehensive MLPA assay for PWS is underway to detect both deletions and methylation abnormalities.
- MLPA represents a promising, cost-effective tool for PWS genetic diagnosis.
Objective:
Prader-Willi syndrome (PWS) is characterized by severe hypotonia and feeding difficulties in early infancy, followed by excessive eating and gradual development of morbid obesity in later infancy or early childhood. Patients with PWS are often too young to manifest sufficient features or have atypical findings, making genetic testing important to confirm the diagnosis of PWS. Approximately 99% of patients with PWS have a diagnostic abnormality in the parent-specific methylation imprint within the Prader-Willi critical region (PWCR) at chromosome 15q11.2-q12. Of them, 70% have a paternal deletion; 25% have a maternal uniparental disomy (UPD); and <5% have a mutation in the imprinting center.
Methods:
Current techniques can identify a diagnostic abnormality, such as paternal deletion or maternal UPD for most of patients with PWS, but they are labor-intensive and cost-expensive. Multiplex ligation-dependent probe amplification (MLPA) is a novel, simple, and cost-effective technique for analysis of relative quantification in a single assay, which has recently been applied for the detection of genomic deletions, duplications, and amplifications in a variety of genes.
Results:
Six out of 20 patients referred for genetic diagnosis of PWS were found to have a deletion by MLPA, confirmed by FISH and DNA methylation analysis with 100% concordance.
Conclusion:
MLPA's high sensitivity and specificity for deletion detection is the same as FISH or Southern blot based analysis. Additional collaborative effort for developing and validating the complete MLPA-PWS assay, for not only detecting deletion but also identifying methylation abnormality, is on going.
