General information The SALSA MLPA
Probemix P223 PHEX is a
research use only (RUO) assay for the detection of deletions or duplications in the
PHEX and
FGF23 genes, which are associated with X-linked hypophosphatemia (XLH; HYP).
XLH is a dominant disorder characterised by growth retardation, rachitic and osteomalacic bone disease, hypophosphatemia, renal defects in phosphate reabsorption, and vitamin D metabolism (Sabbagh et al. 2000). XLH is caused by mutations in the phosphate-regulating endopeptidase gene (
PHEX). A form of autosomal dominant hypophosphatemic rickets (ADHR) is caused by mutation in the
FGF23 gene. The
FGF23 gene encodes a member of the fibroblast growth factor family.
More information is available at
https://www.ncbi.nlm.nih.gov/books/NBK83985/.
Probemix content The SALSA MLPA Probemix P223-B3 PHEX contains 42 MLPA probes with amplification products between 130 and 463 nucleotides (nt). This includes 28 probes for the
PHEX gene, one probe for each exon of the gene and two probes for exons 1, 3, 5, 11, 12, and 15, and four probes for the
FGF23 gene, one probe for each exon and an additional probe for exon 1. 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.