General information
The SALSA MLPA
Probemix P330 PCDH19 is a
research use only (RUO) assay for the detection of deletions or duplications in the protocadherin-19 gene (
PCDH19), which is associated with developmental and epileptic encephalopathy 9 (DEE9), also known as EIEE9 and EFMR.
DEE9 is characterised by seizure with onset in infancy or early childhood and cognitive impairment. Additional features include delayed development of variable severity, autistic signs and psychosis. Despite an X-linked mode of inheritance, which usually affects male carriers, this disease is restricted to females. This is probably due to a mechanism called cellular interference (Niazi et al. 2019).
PCDH19 is subject to X-chromosome inactivation, which leads to a homogeneous population of cells negative for
PCDH19 in males. In heterozygous females, on the other hand, the presence of both
PCDH19-positive and
PCDH19-negative cells affects the communication between the cells and leads to DEE9.
The
PCDH19 gene (6 exons) spans ~119 kb of genomic DNA and is located on chromosome Xq22.1, ~99 Mb from the p-telomere.
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 P330-A4 PCDH19 contains 39 MLPA probes with amplification products between 130 and 483 nucleotides (nt). This includes 14 probes for the
PCDH19 gene, at least two probes for each exon, with the exception of exon 2 for which no probe has been included. Furthermore, this probemix contains seven probes upstream and eight probes downstream of the
PCDH19 gene. In addition, ten reference probes are included that detect locations on the X-chromosome. 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.