The Leprosy Gene

An international research team, led by Dr. Erwin Schurr and Dr. Thomas Hudson, Scientists at the Research Institute of the McGill University Health Centre, have identified a gene on human chromosome 6 that makes people vulnerable to leprosy. The report will be published in the March 2003 issue of the journal Nature Genetics.

Leprosy, a chronic disease caused by infection with the bacteria Mycobacterium leprae, affects approximately one million people worldwide. The World Health Organization has identified 91 countries in which leprosy infection is highly prevalent. Symptoms of leprosy include pigmented skin lesions, permanent nerve damage leading to numbness of the feet and hands and, if left untreated, the disease may result in gross disfiguration including loss of finger, toes, feet and hands. The leprosy bacteria are transmitted through direct personal contact or contaminated respiratory droplets.

Schurr and his colleagues used a technique called "genome scanning" to map the gene. The research team analyzed DNA samples from nearly 100 families who were susceptible to the disease, and found that the families shared a common gene variant on chromosome 6. They then analyzed the DNA of an additional 200 families with leprosy to confirm their findings. "In the last few years advances in technology have made complex genetic analyses, such as those used in this study, possible, "stated Dr. Thomas Hudson. "Without these advances and the cooperation of the families, this research would not have been possible."