Key Features and Values
- Eliminates the need for Southern blot analysis
- Accurately measures the methylation fraction for each FMR1 allele at higher resolution than Southern blot analysis
- Provides increased sensitivity for the detection of lower abundance mosaic alleles
- Includes spike-in digestion and amplification controls to ensure high performance with every sample
- Designed to complement the AmplideX FMR1 PCR Reagents
- Improves turnaround time by fivefold: 10 hours from DNA to data (as compared to 1 week for Southern blot)
The AmplideX mPCR FMR1 Kit employs an innovative PCR-only approach for the detection of methylation status in the FMR1 gene. These reagents determine the extent of methylation of each individual allele in both male and female samples, and thus eliminate the need to run tedious and time consuming Southern blots.
The FMR1 protein is a RNA-binding protein that acts as a global regulator of translation in neurons and is important for synaptic plasticity. Because of its key role in neural development and RNA transport, stability, and translation, this gene is implicated in a number of fragile X-related disorders.
Risk assessment and clinical interpretation of FXS and related disorders are defined by the number of CGG repeats and methylation status of the gene. Based on the number of CGG repeats it is possible to distinguish four types of alleles: unaffected or normal alleles (<45 CGG), intermediate (45-54 CGG), premutation (55-200 CGG) and full mutation (>200 CGG).
Individuals with full mutations (>200 CGG repeats) often present classic FXS, characterised by mental retardation, autism, and emotional and psychiatric challenges due to hypermethylation of the expanded repeats in the FMR1 gene. Moreover, the severity of the phenotype may be associated with methylation status of the expanded allele and not just the number of CGG repeats.
Most testing paradigms for FMR1 disorders rely on a combination of PCR with size resolution by capillary electrophoresis and FMR1 Southern blot analysis which is used to determine the methylation status of the gene. Unfortunately, this workflow is costly, time- and labor-intensive, and requires large amounts of genomic DNA, and the data quality can be ambiguous to interpret. The AmplideX mPCR FMR1 assay provides a fast, simple solution to overcome these issues.
It enables the researcher to amplify and detect the number of the CGG repeats in the FMR1 gene and its associated methylation status in the 5’-untranslated region, without any requirement for Southern blot analysis .
- Filipovic-Sadic et. al. A novel FMR1 PCR method for the routine detection of low abundance expanded alleles and full mutations in fragile X syndrome. Clin Chem. 2010 Mar; 56(3):399-408
- Chen et. al. An information-rich CGG repeat primed PCR that detects the full range of fragile X expanded alleles and minimizes the need for southern blot analysis. J Mol Diagn. 2010 Sep; 12(5):589-600
- Chen et. al. High-resolution methylation polymerase chain reaction for fragile X analysis: evidence for novel FMR1 methylation patterns undetected in Southern blot analyses. Genet Med. 2011 Jun; 13(6):528-38
- Nahhas et. al. Evaluation of the human fragile X mental retardation 1 polymerase chain reaction reagents to amplify the FMR1 gene: testing in a clinical diagnostic laboratory. Genet Test Mol Biomarkers. 2012 Mar; 16(3):187-92
- Juusola et. al. Performance evaluation of two methods using commercially available reagents for PCR-based detection of FMR1 mutation. J Mol Diagn. 2012 Sep;14(5):476-86