[The associations of cyclin-dependent kinase inhibitor 2B antisense RNA 1 gene polymorphisms with the risk of Crohn's disease in Chinese patients].

Objectives: The present study aimed to investigate the associations of cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) gene polymorphisms with the risk of Crohn's disease (CD) in Chinese patients. Methods: From January 2012 to January 2021, a total of 207 CD patients and 545 age-and gender-matched healthy controls were collected from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University. The genotypes of CDKN2B-AS1 (rs1063192, rs10757274, rs10757278, rs1333048, rs2383207) were determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry technique. Unconditional logistic regression analysis was used to analyze the differences of CDKN2B-AS1 polymorphisms between CD patients and healthy controls, as well as their influences on the clinicopathologic characteristics of CD patients. The analyses for linkage disequilibrium and haplotype were further performed by Haploview 4.2 software. Results: The variant genotype (AG+GG) and variant allele (G) of rs1063192 were more prevalent in CD patients than in healthy controls (32.4% vs 24.8%, P=0.036; 18.8% vs 13.6%, P=0.011). The same conclusions were also drawn for homozygous variant genotype (GG) and variant allele (G) of rs10757274 when CD patients were compared with healthy controls (19.8% vs 12.8%, P=0.017; 45.2% vs 38.1%, P=0.012). According to the Montreal Classification Standards, CD patients were stratified into different subgroups. The homozygous variant genotype (GG) and variant allele (G) of rs10757278 were less frequent in the patients with stricturing CD or penetrating CD than in those with non-stricturing and non-penetrating CD (13.7% vs 29.9%, P=0.015; 37.7% vs 50.4%, P=0.022). However, all the correlations above were no longer significant after Bonferroni's correction (all P>0.05). The polymorphic loci of rs10757274, rs2383207, rs10757278, and rs1333048 were in close linkage disequilibrium with each other in CDKN2B-AS1 gene. Compared with healthy controls, the frequency of haplotype AGAC was decreased in CD patients (1.5% vs 4.5%, χ2=7.61, P=0.006), whereas the frequency of haplotype GGAC was obviously increased in CD patients (3.0% vs 0.6%, χ2=14.25, P<0.001). The stratified analysis further showed that the frequency of haplotype AGAC was higher in the patients with stricturing CD or penetrating CD than in those with non-stricturing and non-penetrating CD (3.1% vs 0.4%, χ2=5.31, P=0.021). Conclusions: The variations of CDKN2B-AS1 (rs1063192, rs10757274, rs10757278, rs1333048, rs2383207) may not independently affect the risk of CD. Among the haplotypes constructed by rs10757274, rs2383207, rs10757278, and rs1333048, the haplotype AGAC may reduce the risk of CD, whereas it may increase the risk of stricturing or penetrating in CD patients. In addition, the haplotype GGAC may increase the risk of CD.