General information: The SALSA MLPA Probemix P454 CGD is a research use only (RUO) assay for the detection of deletions or duplications in the CYBA, CYBB, NCF2 and NCF4 genes, which are associated with chronic granulomatous disease (CGD).

Patients with chronic granulomatous disease (CGD) suffer from recurrent, life-threatening bacterial and fungal infections of skin, airways, lymph nodes, liver, brain and/or bones. CGD is a rare (∼1:250 000 births) recessive disorder caused by mutations in any one of the five components of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in phagocytes. This enzyme generates superoxide and is essential for intracellular killing of pathogens by phagocytes. The genes encoding the five NADPH oxidase components are CYBB (located on the X-chromosome), and the autosomal genes CYBA, NCF1, NCF2 and NCF4. Approximately 70% of the CGD patients have a mutation in CYBB. The remainder of the patients have mutations in NCF1 (~ 20%), in CYBA (~ 5%) or in NCF2 (~ 5%). Only one patient with NCF4 mutations has been reported (Matute et al. 2009). Copy number variations account for approximately 15% of pathogenic variants in each of the CYBA, CYBB and NCF2 genes.

More information is available at https://www.ncbi.nlm.nih.gov/books/NBK99496/.

Probemix content: The SALSA MLPA Probemix P454-A2 CGD contains 38 MLPA probes with amplification products between 129 and 454 nucleotides (nt). This includes three probes for the CYBA gene, 12 probes for the CYBB gene, ten probes for the NCF2 gene and four probes for the NCF4 gene and. Due to the presence of pseudogenes of NCF1, it was not possible to include probes specific for the NCF1 gene in this probemix. In addition, nine 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.