General information
The SALSA MLPA Probemix P455 LZTR1 is a research use only (RUO) assay for the detection of deletions or duplications in the LZTR1 gene, which is associated with schwannomatosis.
Schwannomatosis (MIM 162091), the third major form of neurofibromatosis, is a late-onset tumour predisposition disorder that is clinically and genetically distinct from neurofibromatosis types 1 (MIM 162200) and 2 (MIM 101000). In approximately 50% of the schwannomatosis cases, germline mutations in SMARCB1 have been identified (Smith et al. 2012). Genetic analysis of the schwannomas showed that mutation of SMARCB1 is often followed by loss of heterozygosity at the 22q region and subsequent mutation of the NF2 gene. Together, these three events result in biallelic loss of the SMARCB1 and NF2 tumour suppressor genes in the schwannomas. In 22q-related schwannomatosis cases without constitutional SMARCB1 mutations, Piotrowski identified germline mutations in LZTR1 (Piotrowski et al. 2014). Mutations in LZTR1 may account for up to 80% of the schwannomatosis cases lacking mutations in SMARCB1.

More information is available at https://www.ncbi.nlm.nih.gov/books/NBK487394/.

Probemix content
The SALSA MLPA Probemix P455-A1 LZTR1 contains 45 MLPA probes with amplification products between 124 and 500 nucleotides (nt). This includes 20 probes for the LZTR1 gene, one probe for each exon with the exception of exons 4 and 17 and two probes for exon 21. Furthermore, this probemix also contains 11 flanking probes targeting the 22q11 and 22q12 chromosomal regions surrounding LZTR1 gene. In addition, 14 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.