title: Mosaic 13q14 deletions in peripheral leukocytes of non-hematologic cancer cases and healthy controls.
abstract: Loss of 13q14.3 is a chromosomal event found in ~50% of B-cell chronic lymphocytic leukemia (CLL) and monoclonal B-cell lymphocytosis (MBL) cases. Surveys of somatic alterations in solid tumors have shown sporadic 13q14.3 loss in many different tumor types, but not at high frequency in any specific tumor type. In our recent survey of the single-nucleotide polymorphism (SNP) microarray data from 127 000 cancer-free or solid tumor cases, we observed mosaic 13q14.3 loss as common autosomal somatic large structural events (>2 Mb in size) in blood and buccal-derived DNA. Herein, we examined this region more closely investigating structural mosaic events <2 Mb using SNP microarray data in 46 254 non-hematologic cancer cases and 36 229 controls. We detected 60 individuals with 13q14.3 mosaic loss, 1 mosaic copy neutral uniparental disomy and 13 individuals with homozygosity. Although 13q14.3 loss size was variable, the minimally deleted region (MDR) (chr13: 49 590 000-49 983 100; GRCh36) was comparable to what is classically reported in MBL and CLL. Breakpoint analysis of the estimated boundaries reveals enrichment for genes and open chromatin. The frequency of 13q14.3 loss significantly increases with increasing age (P-value=0.028), but was not significantly different between non-hematological cancer cases and controls (0.084% versus 0.058%; P-value=0.19). These findings suggest that mosaic 13q14.3 losses accumulate with age. Individuals with detected mosaic 13q14.3 deletions may be early, undetected cases of MBL or CLL, but not necessarily all will develop MBL and CLL.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.
authors.forename: Mitchell J
authors.identifier: http://orcid.org/0000-0001-6538-9705
authors.initials: MJ
authors.lastname: Machiela
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.|Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick, MD, USA.
authors.forename: Weiyin
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.
authors.forename: Neil
authors.initials: N
authors.lastname: Caporaso
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.|Laboratory of Experimental Immunology, Center for Cancer Research, Frederick National Laboratory, Frederick, MD, USA.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0003-2234-0631
authors.initials: M
authors.lastname: Dean
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, GA, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Gapstur
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.
authors.forename: Lynn
authors.initials: L
authors.lastname: Goldin
authors.affiliation: Epidemiology Research Program, American Cancer Society, Atlanta, GA, USA.
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Stevens
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.|Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick, MD, USA.
authors.forename: Meredith
authors.initials: M
authors.lastname: Yeager
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Chanock
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D019457:Chromosome Breakage; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13; D056915:DNA Copy Number Variations; D005260:Female; D055106:Genome-Wide Association Study; D023281:Genomics / Q000379:methods; D006801:Humans; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009030:Mosaicism; D009369:Neoplasms / Q000175:diagnosis / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide