RESUMEN
Background/Purpose: Genetic factors play an important role in the pathogenesis of vitiligo. Cyclooxygenase 2 (COX2) gene induced by ultraviolet radiation controls the synthesis of prostaglandins, which are are found to be beneficial in treating vitiligo. COX2 gene polymorphism has been previously evaluated in Chinese population. We aimed to study the relation between two common COX2 gene polymorphisms with vitiligo and its subtypes amongEgyptian patients. Patients and Methods: This study included 200 participants (100 vitiligo patients and 100 healthy controls). COX2-765G/C and -1195A/G gene polymorphism was studied by restriction fragment length polymorphism polymerase chain reaction analysis and the results were compared between the two groups and among different subtypes of vitiligo. Results: Frequency of COX2-1195 AA, AG, GG genotypes showed no significant association among patients with vitiligo (P = 0.626, 0.321, 0.08, respectively); those with generalized vitiligo (P = 0.739, 0.291, 0.101, respectively) and those with segmental vitiligo (P = 0.410, 1.00, 0.676, respectively) compared to the control group. Regarding COX2-765G/C genotypes, GG genotype was more frequent among patients with vitiligo [84 (84%)] compared to controls [63 (63%)] (P = 0.001). GC genotype was significantly less frequent [15 (15%)] among patients compared to controls [32 (32%)] (P = 0.005). Generalized and segmental types of vitiligo also showed no significant difference in the frequency of COX2-765G/C genotypes compared with controls. Limitations: Being a pilot study, a relatively small number of participants were included. Conclusion: COX2-1195A/G gene polymorphism is not associated with the risk of developing vitiligo or with vitiligo subtypes. COX2-765 GG genotype is associated with vitiligo, especially of the generalized type.
RESUMEN
Abstract: Background: The association of glutathione S-transferases M1/T1 (GSTM1/T1) null polymorphisms with vitiligo was proposed in several studies including two Egyptian studies with contradictory results. Objective: The aim here was to assess the association between GSTM1/T1 null polymorphisms and the susceptibility to vitiligo in a larger sample of Egyptian patients with generalized vitiligo. Methods: This study included 122 vitiligo patients and 200 healthy controls that were age, and gender matched. Assessment of GSTM1/T1 gene polymorphisms was done using a multiplex polymerase chain reaction (PCR). Results: Increased odds of generalized vitiligo was observed with the null genotypes of GSTM1 and GSTT1 polymorphisms (P<0.05). Controls with GSTM1 null/GSTT1+ heterozygosis presented with a 2.97 odds protection from having generalized vitiligo (OR=2.97, 95%CI=1.1-7.7) (P=0.02) compared with patients. Study Limitations: Small sample size of patients. Conclusions: This study showed a significant trend towards an association with the combination of the GSTM1/GSTT1 double null polymorphism and generalized vitiligo. Individuals with GSTM1 null/GSTT1+ heterozygosis have a 2.97 odds protection from having generalized vitiligo compared with patients. It was is the first time, to our knowledge, that such an association has been reported.