Eight Genes Identified in Alopecia Areata
A few times each week, I pause from a busy clinic to explain to patients with alopecia areata an incredible study published in 2010. I begin by telling my patients that what I’m about to tell them is among the most important studies in hair diseases published in the last few years.
Dr. Angela Christiano and her colleagues at New York’s Columbia University set out to investigate which genes are involved in the development of alopecia areata. The researchers addressed this question by comparing the DNA of about 1000 patients who had alopecia areata to about 3000 patients who did not have the disease.
What did the study show?
1) This study identified eight genes which are strongly implicated in alopecia areata. Three of the genes are expressed in the hair follicle and five of the genes are involved in the immune system.
2) The genes implicated in alopecia areata were found to be similar to the genes implicated in two other autoimmune diseases – namely type 1 diabetes and rheumatoid arthritis.
3) Patients who carried more of the implicated genes in their DNA were most likely to progress to alopecia universalis (complete loss of all scalp and body hair).
Why is the study important?
1. New research questions to can be addressed. This information may now allow researchers to design future studies to address a multitude of important questions, including:
Why do some patients develop only a small patch of hair loss whereas others develop extensive hair loss?
Why do some patients develop alopeia areata at young ages whereas other develop the condition later in life?
Why do some patients respond well to certain treatments whereas others do not?
2. New treatments for alopecia areata may be possible in the future. The findings of this study may allow researchers to design better treatments. There are many drugs already in various phases of research for type 1 diabetes and rheumatoid arthritis. Seeing that alopecia areata is more closely related to these two conditions than previously thought, it might be possible to use diabetes and arthritis drugs to treat alopecia areata.
3. New genetic tests might eventually become available for patients. Given that Dr. Christiano was able to show which subgroup of patients were likely to progress to severe disease (alopecia universalis), she is now creating a genetic test that could eventually be used in the clinic can predict which patients are most likley to progress to lose all of their hair.
This study is very important. For years it was thought that alopecia areata was closely related to diseases like psoriasis or vitiligo. Dr. Christiano's work points us in a different direction.
This article was written by Dr. Jeff Donovan, a Canadian and US board certified dermatologist specializing exclusively in hair loss.