Majority of malignant lymphoma arising from the ocular adnexae are ocular adnexal MALT lymphomas (OAL). Several genetic abnormalities, including t(14;18)(q32;q21), trisomy 18 and trisomy 3 have been reported in OAL. However, none of them are found in more than half of cases with OAL by conventional methods. High density Single Nucleotide Polymorphism (SNP) array analysis with CNAG/AsCNAR algorithm allows high-resolution and genome-wide detection of both loss of heterozygosity (LOH) and copy number abnormality, especially uniparental disomy (UPD), without depending on the availability of paired normal DNA (

Yamamoto et al, Am J Hum Genet. 2007; 81:114–26
). UPD is acquired by somatic recombination and therefore not detected by conventional cytogenetic analysis or array CGH. In this study we analyzed DNA from OAL for the presence of LOH with or without copy number changes. Tissue samples from patients with OAL at our institute between 1995 and 2003 (N=32) were subject to SNP-array (250K NspI) analysis with CNAG/AsCNAR algorithm. The patients included 21 males and 11 females, and the median age of 56.5 years at the time of diagnosis (range, 15–90 years). Clinical stage was I (29 cases), II (1 case), and IV (2 cases). Trisomy of 3, 18, and 21 were found in 9, 7 and 1 cases, respectively. Overall, LOH due to UPD more than one chromosomal band were found in 16 cases (50%). Recurrent one allele deletion was detected at 6q23-24, 12p13 and 17q21 (N=15, 15 and 21, respectively). In total, 28 (82%) among 32 cases showed one or more of the above changes. Characterization of these recurrent genetic abnormalities might reveal the pathogenesis of OAL.

Topics:
alleles, loss of heterozygosity, lymphoma, mucosa-associated lymphoid tissue, uniparental disomy, dna, cytogenetic analysis, edward's syndrome, lymphoma, mucosa-associated lymphoid tissue, tissue specimen

Author notes

Disclosure: No relevant conflicts of interest to declare.

2007, The American Society of Hematology
2007
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