General information
The SALSA MLPA Probemix P209 Glycine Encephalopathy is a research use only (RUO) assay for the detection of deletions or duplications in the GLDC, AMT, and GCSH genes, which are associated with Glycine encephalopathy (GCE).

GCE, also known as nonketotic hyperglycinemia (NKH), is an inborn error of glycine metabolism in which large quantities of glycine accumulate in all body tissues, including the brain. This is due to deficient glycine cleavage enzymes. The majority of the GCE cases present themselves in the neonatal phase. This leads to progressive lethargy, hypotonia, and myoclonic jerks which in turn leads to apnea and often death.
Three genes are known to cause GCE. Glycine dehydrogenase (GLDC) encodes the P-protein component in the glycine cleavage system (GCS). This gene is responsible for 70-75% of the disease cases. Aminomethyltransferase (AMT) encodes the T-protein of the GCS complex and accounts for 20% of the GCE cases. Glycine cleavage system protein H (GCSH), which is the H-protein of the GCS complex accounts for <1% of the disease cases. Around 5% of individuals with GCE do not have a mutation in any of these three genes.

More information is available at https://www.ncbi.nlm.nih.gov/books/NBK1357/.

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 P209-C2 Glycine Encephalopathy contains 50 MLPA probes with amplification products between 124 and 463 nucleotides (nt). This includes 26 probes for the GLDC gene, one probe for each exon and two probes for exon 1, nine probes for the AMT gene, one probe for each exon, and five probes for the GCSH gene, one probe for each exon. In addition, ten reference probes are included that detect autosomal chromosomal locations. 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 MLPA General Protocol and online at www.mrcholland.com.