General information
The SALSA MLPA Probemix P341/P342 PKHD1 is a research use only (RUO) assay for the detection of deletions or duplications in the PKHD1 gene, which is associated with autosomal recessive polycystic kidney disease (ARPKD).

ARPKD is a hereditary and severe form of polycystic kidney disease, affecting the kidneys and the hepatic biliary tract. The clinical spectrum is widely variable, with most cases presenting during infancy. The fetal phenotypic features classically include enlarged and echogenic kidneys, as well as oligohydramnios secondary to a poor urine output. Up to 50% of the affected neonates die shortly after birth, as a result of severe pulmonary hypoplasia and secondary respiratory insufficiency. In the subset that survives the perinatal period, morbidity and mortality are mainly related to severe systemic hypertension, renal insufficiency, and portal hypertension due to portal-tract fibrosis. Defects in the PKHD1 gene are the cause of all typical forms of ARPKD.

More information is available at https://www.ncbi.nlm.nih.gov/books/NBK1326/.

Probemix content
The SALSA MLPA Probemix P341-B4 PKHD1 mix 1 contains 44 MLPA probes with amplification products between 136 and 472 nucleotides (nt). This includes 35 probes for the PKHD1 gene and nine reference probes that detect autosomal chromosomal locations. The SALSA MLPA Probemix P342-C1 PKHD1 mix 2 contains 44 MLPA probes with amplification products between 130 and 463 nucleotides (nt). This also includes 35 probes for the PKHD1 gene and nine reference probes that detect autosomal chromosomal locations. Both probemixes together include 70 probes targeting 65 out of the 67 exons of the PKHD1 gene, one probe for each exon of the gene with the exception of exon 17 and 44, and two probes are present for exons 27, 35, 36, 37, and 53. Complete probe sequences and the identity of the genes detected by the reference probes are available online (www.mlpa.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.mlpa.com.