Retour

Behc
et’s disease (BD) is a multisystem inflammatorydisease characterized by recurrent orogenital ulceration,ocular inflammation and skin lesions. Reducedplasma nitric oxide (NO) levels in patients with BDhave been implicated in the development of the endothelialabnormalities and thrombotic complicationsoccurring in these patients. Polymorphisms in theendothelial nitric oxide synthase gene (NOS3) havebeen inconsistently associated with BD. This inconsistencymay derive from population stratification secondaryto ethnic diversity, and consideration limitedto only one rather than combinations of polymorphisms.We studied three genetic variations in the

NOS3 gene: a single nucleotide polymorphism in the

promoter region
786T>C, in exon 7 (Glu298Asp),

and a variable number of tandem repeats in intron 4

(4a4b) of the NOS3 gene in 100 unrelated Tunisian

patients with BD and 148 healthy controls. In addition,

we also examined the association of NOS3 gene

haplotypes with BD. Allele Asp298 was significantly

more frequent in patients with BD than in controls

(P = 0.005, OR = 1.70, 95% CI 1.14–2.54).In

contrast, distribution of alleles and genotypes of

786T>C and 4a4b polymorphisms was not different

between the control and BD group. However, the frequency

of Asp-T-4b haplotype was significantly higher in patients with BD than in healthy controls. By gender,

the signification remained only for heterozygous

men (P = 0.03) and homozygous women (P = 0.02).

These results suggest that Glu298Asp polymorphism

of the NOS3 gene is associated with BD susceptibility

in Tunisian patients.