Screening of R122H and N29I mutations in the PRSS1 gene and N34S mutation in the SPINK1 gene in Mexican pediatric patients with acute and recurrent pancreatitis.

OBJECTIVES: The study's objective was to assess the association between the PRSS1 R122H and N29I and the SPINK1 N34S mutations and acute pancreatitis (AP) and recurrent pancreatitis in Mexican pediatric patients. METHODS: The N34S and R122H mutations were detected using polymerase chain reaction-restriction fragment length polymorphism, and the N29I mutation was detected using allele-specific polymerase chain reaction in 92 pancreatitis patients (58 AP and 34 recurrent pancreatitis patients) and 144 controls. RESULTS: We found 1 mutated allele in 4 (4.3%) of 92 pancreatitis patients and none in the controls. All 4 patients bearing mutations had AP, with a frequency of 6.8% (4/58). Three (5.2%) of 58 patients were heterozygous for the N34S mutation, and 1 (1.7%) of 58 patients was heterozygous for the N29I mutation. The comparison between the AP and control groups revealed both a significant number of patients carrying any mutations in the screened genes (P = 0.008) and bearing the N34S mutation (P = 0.023). Moreover, we found that the N34S G allele increased the risk of developing AP (odds ratio, 10.3; confidence interval, 1.1-248.8). CONCLUSIONS: Patients bearing the N34S G allele exhibited a 10-fold increased risk of developing AP compared with controls, suggesting that the SPINK1 N34S mutation represents an etiologic risk factor for AP in our Mexican pediatric patients.

Tumor necrosis factor-alpha gene promoter -308G/A and -238G/A polymorphisms in Mexican patients with type 2 diabetes mellitus.

The association between some Tumor necrosis factor-alpha (TNF-α) promoter polymorphisms and Type 2 diabetes mellitus (T2DM) remains controversial. Ethnic differences may play a role in these conflicting results. The aim of this study was to investigate the association between -308G/A and -238G/A polymorphisms located in the promoter region of the TNF-α gene and T2DM in Mexican mestizo patients. Nine hundred four individuals (259 patients with T2DM and 645~controls) were genotyped for the -308G/A and -238G/A polymorphisms by PCR--RFLP. We found that the -238A allele increased the risk of developing T2DM in Mexican patients (OR=1.57, 95% CI: 1.07-2.29; p=0.018). Moreover, we found that the frequency of the GA haplotype (created by the -308G and -238A alleles) was significantly increased in patients with T2DM when compared with controls (OR =1.56, 95% CI: 1.05-2.31; p=0.026). Our results suggest that the -238G/A polymorphism and a specific haplotype (GA) are genetic risk factors for the development of T2DM in Mexican population.