By Syed Akbar
Leucoderma, a skin pigmentation problem characterised by white patches on the body, is not caused by genetic defect in South Indian population.
Leucoderma or vitiligo is prominently linked to the defect in a gene (CTLA-4) in different populations around the world, but a group of researchers from Hyderabad argues that the gene has nothing to do with leucoderma patients living in Southern India.
The research, carried out by the department of genetics attached to Osmania University, Mahavir Hospital and Research Centre, and the Central Research Institute of Unani Medicine, established that there were no significant differences between frequencies of CTLA-4 genotypes in patients and those in the control group (healthy individuals). There were also no significant differences between allelic (variant forms a gene) frequencies in patients and matched control groups
In people suffering from leucoderma, there is loss of functional melanocytes (cells that give black pigmentation to the skin) and melanin (the coloured protein) in the skin. This leads to appearance of white patches on the face and other parts of the body. The skin problem affected about two per cent of the people all over the world. In India leucoderma is seen in one out of every 200 people.
"One of the candidate genes that has a strong association with several autoimmune diseases including leucoderma is CTLA-4 gene located in chromosome 2q33 region. In our investigation we did not find correlation between genotypes of patients and disease type, and gender," according to
one of the researchers Dr Syed Rabbani.
The team studied as many as 175 unrelated south Indian vitiligo patients, besides 180 healthy individuals. None of the healthy individuals had any evidence of vitiligo and autoimmune diseases or a positive family history of vitiligo and autoimmune diseases.
The research showed that in South Indian patients, there was no difference in familial history among male and female patients. In contrast to earlier studies, the city team did not find any association between the gene (CTLA-4 exon 1 polymorphism) and the emergence of leucoderma or vitiligo.
"Lack of association between CTLA-4 gene polymorphism and vitiligo might therefore, suggest the involvement of other immune regulatory genes and/or reflect a different nature or multiple etiologies for vitiligo," he pointed out.