Design and validation of a New MLPA-Based assay for the detection of RS1 gene deletions and application in a large family with X-linked juvenile retinoschisis

Annalisa Nicoletti, Lucia Ziccardi, Paolo Enrico Maltese, Sabrina Benedetti, Orazio Palumbo, Michelina Rendina, Leonardo D'Agruma, Benedetto Falsini, Xinjing Wang, Matteo Bertelli

Research output: Contribution to journalArticle


Aims: X-linked juvenile retinoschisis (XLRS) is a severe ocular disorder that can evolve to blindness. More than 200 different disease-causing mutations have been reported in the RS1 gene and approximately 10% of these are deletions. Since transmission is X-linked, males are always affected and females are usually carriers. The identification of female carriers is always important and poses a technical challenge. Therefore, we sought to develop a multiplex ligation dependent probe amplification (MLPA)-based method to identify deletions or duplications in this gene. We then used our assay to study a large XLRS family. Methods: We designed six probes specific for each RS1 exon and then optimized and validated our method using control samples with known gene deletions. In the XLRS family, RS1 gene copy number variation was assessed by "home-made" MLPA analysis and by single nucleotide polymorphism (SNP) array analysis using the Cyto- Scan HD Array. Direct sequencing was used for deletion breakpoint mapping. Results: Our assay detected all deletions in control samples. All affected males of the family were positive for a deletion of exon 2 of the RS1 gene (RS1:NM000330:c.53-78+?del). Carrier females were also identified. Conclusion: Our method is easily replicated, reliable, and inexpensive and allows female carriers to be detected. This is the first report of deep characterization of a whole exon deletion in the RS1 gene.

Original languageEnglish
Pages (from-to)116-121
Number of pages6
JournalGenetic Testing and Molecular Biomarkers
Issue number2
Publication statusPublished - Feb 1 2017



  • MLPA
  • Retinoschisis
  • RS1
  • XLRS

ASJC Scopus subject areas

  • Genetics(clinical)

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