The 253‐kb inversion and deep intronic mutations in UNC13D are present in North American patients with familial hemophagocytic lymphohistiocytosis 3. Issue 6 (28th January 2014)

• Record Type: Journal Article
• Authors: Qian, Yaping; Johnson, Judith A.; Connor, Jessica A.; Valencia, C. Alexander; Barasa, Nathaniel; Schubert, Jeffery; Husami, Ammar; Kissell, Diane; Zhang, Ge; Weirauch, Matthew T.; Filipovich, Alexandra H.; Zhang, Kejian
• Is Part Of: Pediatric blood & cancer. Volume 61:Issue 6(2014:Jun.)
• Page Start: 1034
• Page End: 1040
• Publication Date: 2014-01-28
• Subjects: Tumors in children -- Periodicals; Blood -- Diseases -- Periodicals; Cancer in children -- Periodicals; 618.92
• DOI: 10.1002/pbc.24955
• Languages: English
• ISSNs: 1545-5009

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pbc24955-sec-0001" sec-type="section"> <title>Background</title> <p>The mutations in <italic>UNC13D</italic> are responsible for familial hemophagocytic lymphohistiocytosis (FHL) type 3. A 253‐kb inversion and two deep intronic mutations, c.118–308C > T and c.118–307G > A, in <italic>UNC13D</italic> were recently reported in European and Asian FHL3 patients. We sought to determine the prevalence of these three non‐coding mutations in North American FHL patients and evaluate the significance of examining these new mutations in genetic testing.</p> </sec> <sec id="pbc24955-sec-0002" sec-type="section"> <title>Procedure</title> <p>We performed DNA sequencing of <italic>UNC13D</italic> and targeted analysis of these three mutations in 1, 709 North American patients with a suspected clinical diagnosis of hemophagocytic lymphohistiocytosis (HLH).</p> </sec> <sec id="pbc24955-sec-0003" sec-type="section"> <title>Results</title> <p>The 253‐kb inversion, intronic mutations c.118–308C > T and c.118–307G > A were found in 11, 15, and 4 patients, respectively, in which the genetic basis (bi‐allelic mutations) explained 25 additional patients. Taken together with previously diagnosed FHL3 patients in our HLH patient registry, these three non‐coding mutations were found in 31.6% (25/79) of the FHL3 patients. The 253‐kb inversion, c.118–308C > T and c.118–307G > A accounted for 7.0%, 8.9%, and 1.3% of mutant alleles, respectively. Significantly, eight novel mutations in <italic>UNC13D</italic> are being reported in this study. To further evaluate the expression level of the newly reported intronic mutation c.118–307G > A, reverse transcription PCR and Western blot analysis revealed a significant reduction of both RNA and protein levels suggesting that the c.118–307G > A mutation affects transcription.</p> </sec> <sec id="pbc24955-sec-0004" sec-type="section"> <title>Conclusions</title> <p>These specified non‐coding mutations were found in a significant number of North American patients and inclusion of them in mutation analysis will improve the molecular diagnosis of FHL3. Pediatr Blood Cancer 2014;61:1034–1040. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>