Vitiligo

Mar 17, 2008
Romanian Community Provides Insight Into Genetic Factors
Associated With Vitiligo

An isolated, inbred Romanian community has a higher than
average frequency of the skin disease vitiligo and other
autoimmune diseases, suggesting a genetic variation that
may indicate susceptibility to the condition in a broader
population, according to a report in the March issue of
Archives of Dermatology, one of the JAMA/Archives journals.

Vitiligo is a disorder in which progressive patches of
skin, hair and mucous membranes lose color due to a
decrease in the number of pigment-producing cells known as
melanocytes, according to background information in the
article. Vitiligo affects about 0.38 percent of whites and
occurs with similar frequency in populations worldwide.
Researchers are attempting to identify the genes
responsible for susceptibility to vitiligo, in part to
identify pathways through which effective treatments might
be developed.

Stanca A. Birlea, M.D., Ph.D., and colleagues at the
University of Colorado Denver , Aurora , Colo. , studied
1,673 residents of a geographically isolated community in
the mountains of northern Romania between 2001 and 2006.
The researchers identified patients with vitiligo and
obtained information on demographic data, genealogies,
occurrence of other diseases and family structure. The skin
of patients with vitiligo and their relatives was examined.

During the study, researchers identified and examined 51
patients with vitiligo. “The 2.9 percent frequency of
vitiligo in the study community is 19.3 times its 0.15
percent frequency in the five surrounding villages, 7.5
times that among whites on the island of Bornholm, 5.7
times that among individuals in Calcutta, India and 22.5
times that among Han Chinese in Shaanxi Province, China,
the only other populations for which empirically determined
prevalence estimates have been published,” the authors
write. Rates of other autoimmune diseases, including
thyroid disease, adult-onset type 1 diabetes and rheumatoid
arthritis, were also elevated in the community.

However, the average age at which symptoms of vitiligo
first developed was 36.5 years, significantly older than
the average age of onset among white individuals (24.2
years). Analyses indicated that this unusual factor most
likely was not genetic. “Whereas disease susceptibility
seems to involve a major genetic component, actual onset of
vitiligo in genetically susceptible individuals seems to
require exposure to environmental triggers,” the authors
write.

The community’s isolation may make it easier for
researchers to identify mutated genes that increase risk
for vitiligo in this population, they conclude. “While this
gene variant is of particular importance in this isolated
special population, it likely is also involved in disease
susceptibility in the broader white population and, thus,
is of broader importance,” they write.

Arch Dermatol. 2008; 144[3]:310-316.