General Information: The SALSA MLPA Probemix P361 and P362 USH2A is a research use only (RUO) assay for the detection of deletions or duplications in the USH2A gene.

Usher syndrome is a clinically and genetically heterogeneous autosomal recessive disorder characterized by sensorineural hearing deficiencies at birth and later development of progressive retinitis pigmentosa (RP). It is the most frequent cause of combined deafness and blindness in adults and affects 3 to 6% of children born with hearing impairment. In brief, patients with Usher syndrome type II have mild hearing impairment with normal vestibular responses. Type II is the most common form of three Usher syndromes. Mutations within the USH2A gene have been associated with Usher syndrome type IIa and retinitis pigmentosa.

More information is available at https://www.ncbi.nlm.nih.gov/books/NBK1341

Probemix content: The SALSA MLPA probemixes P361-A3 USH2A mix 1 and P362-A3 USH2A mix 2 both contain 45 probes with amplification products between 130 nt and 454 nt, and between 130 nt and 477 nt respectively. The USH2A gene (72 exons) spans ~800 kb of genomic DNA, and is located on chromosome 1q41, ~216 Mb from the p-telomere. The P361-A3 and P362-A3 probemixes together contain one probe for each exon of the USH2A gene. The P361-A3 probemix contains probes for the odd exon numbers of USH2A and the P362-A3 probemix contains probes for the even exon numbers of USH2A. In both probemixes, nine reference probes are included, that detect different autosomal chromosomal locations.

These probemixes contain 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, 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.