General information
The SALSA MLPA
Probemix ME034 Multi-locus Imprinting is a
research use only (RUO) assay for the detection of aberrant methylation of one or more sequences in 14 different differentially methylated regions (DMRs) on eight different chromosomes. Applications include the study of multi-locus imprinting disturbances and finding the parental origin of triploid pregnancies. This probemix can also be used to detect deletions/duplications in the aforementioned chromosomal regions.
Genomic imprinting is the monoallelic expression of genes, dependent on the parental origin of the chromosome. It plays a role in growth and development. Imprinting disturbances originate from a disturbance in this monoallelic expression by disruption or epimutation of imprinted genes (Ishida et al. 2013).
Multi-locus imprinting disturbances (MLIDs) have been identified in several patients. For example, a considerable number of patients with 11p15-associated imprinting disturbances have been reported to also carry methylation changes at other chromosomal locations (Eggermann et al. 2014).
Triploidy is one of the most common chromosomal abnormalities, occurring in 1–2% of all human conceptuses. Triploid pregnancies can have either the chromosomal constitution of two maternal and one paternal set (digyny) or two paternal and one maternal set (diandry). The distinction between digyny and diandry is clinically important because the risk of the conceptus being molar and thereby inducing a risk for maternal complications (such as pre-eclampsia, postpartum haemorrhage and persistent gestational trophoblastic disease) is determined by the parental composition of the genome. As shown by Joergensen et al. (2013 and 2014), Methylation-specific MLPA (MS-MLPA) analysis of imprinted regions is a reliable method to distinguish triploidies with a double paternal contribution from triploidies with a double maternal contribution.
This SALSA MLPA probemix is not CE/FDA registered for use in diagnostic procedures. Purchase of this product includes a limited license for research purposes.
Probemix content
The SALSA MLPA Probemix ME034-D1 Multi-locus Imprinting contains 40 (methylation-specific) probes with amplification products between 122 and 465 nucleotides (nt). 27 of these probes are methylation-specific and contain an HhaI recognition site and provide information on the methylation status of different sequences in genes known to be methylated in either the paternal or the maternal allele. This includes three probes for each of the following genes:
H19 and
PEG3, two probes for each of the following genes:
KCNQ1OT1,
MEST,
MEG3,
MEG8, SNRPN, PLAGL1, GRB10, and
ZNF597, and five probes for the
GNAS complex locus. All probes present will also give information on copy number changes in the analysed sample. In addition, eleven reference probes are included that are not affected by HhaI digestion and detect genes located outside the chromosomal regions targeted by this probemix. Also, two digestion control probes are included in this probemix indicating whether or not restriction endonuclease digestion in the MS-MLPA reaction was complete. Complete probe sequences and the identity of the genes detected by the reference probes are available online (
www.mrcholland.com).
This probemix contains nine quality control fragments generating amplification products between 64 and 105 nt: four DNA Quantity fragments (Q-fragments), two DNA Denaturation fragments (D-fragments), one Benchmark fragment, and one chromosome X and one chromosome Y-specific fragment. More information on how to interpret observations on these control fragments can be found in the MS-MLPA General Protocol and online at
www.mrcholland.com.