الفهرس 
VitiligoOnly 14 pages are availabe for public view
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Abstract
Vitiligo is a multifactorial polygenic disorder of the skin. It is caused by the complex interaction between genotypic and phenotypic environment of an individual. It is characterized by white patches due to loss of the melanocytes, creating a psychological and social stigma especially in darker skin phototypes.
Exact pathogenesis of vitiligo is still unclear; however, more persuasive evidences are genetic, environmental, oxidative stress, biochemical, and immunological factors that seem to act together or individually to generate a lenient environment for the melanocyte loss.
The imbalance between oxidative stress and antioxidation seems to induce excess production of ROS in the epidermal layer of skin, which may be an important pathogenic factor of vitiligo.
Humans express two forms of N-acetyltransferases (NAT): NAT1 and NAT2, both genes are polymorphic. N-acetyltransferase 2 polymorphically expresses at a number of tissues such as liver and epidermis.
N-acetyltransferase metabolizes wide range of xenobiotic compounds that may be responsible for ROS production and melanocyte damage via the acetylation process. It catalyzes the metabolic inactivation or activation of environmentally exposed compounds, such as plethora of hydrazine and arylamines by the pathways of n- or o-acetylation.
The aim of this study was to investigate the effect of the NAT2 gene polymorphism 481C>T (rs1799929) in non-segmental vitiligo and NAT2 serum level and to compare the findings to the clinical information.
This study was conducted on 65 unrelated patients having NSV, in addition to 65 age and sex apparently healthy volunteers as a control group. Cases of vitiligo were selected from Dermatology Outpatient Clinic, Menoufia University Hospital while the control subjects were selected from those attending Plastic Surgery Department.
Results of the present study showed that:
Onset of the disease was gradual in all of cases. Course of the disease was progressive mostly then stationary and regressive, respectively. Duration of the disease ranged from 6 months -10 years. Regarding family history of vitiligo, most of cases were negative. Koebnerization was present in more than half of the cases. Spontaneous repigmentation was absent in all cases. Regarding the type of vitiligo, most of Cases were having generalized vitiligo then acrofacial, focal and universal types, respectively. There was significant difference between cases and controls regarding NAT2 genotype.CC genotype (rapid acetylator phenotype) was more dominant in controls than cases. TT genotype (slow acetylator genotype) and CT genotypes (rapid acetylator phenotype) were dominant in cases than in controls. TT and CT genotypes were significantly observed in vitiligo patients and increased the risk for vitiligo development by about 5 and 6.5 folds, respectively. There was significant difference between cases and controls regarding NAT2 allele. C allele was more prominent in controls while T allele was more dominant in cases. T allele significantly increased the risk for vitiligo development by about 3 folds.