Another Medical Cold Case Cracked by the MUHCâs âDr. Houseâ
A team from the Research Institute of the Âé¶čAV Health Centre (RI-MUHC) led by Dr. Donald Vinh, the RIâs so-called âDr. Houseâ because of his research into rare diseases, has discovered a new human disease and the gene responsible for it, paving the way for the proper diagnosis of patients globally and the development of new therapies. Their findings are published in the Journal of Experimental Medicine.
Dr. Vinh has coined this new disease âcombined immunoficiencyâ or âCID,â and the gene responsible for it âICOSLGâ. The disease is characterized by a weakened immune system and, because the body's ability to fight off infections is crippled, patients are susceptible to recurrent life-threatening infections such as pneumonias and debilitating infections, such as progressive warts.
New disease that affects the immune system
âThis discovery will help patients who have escaped diagnosis - to now - be correctly diagnosed. By doing so, patients could benefit from aggressive monitoring of potential complications and earlier implementation of tailored therapies,â explains Dr. Vinh, a researcher from the Infectious Diseases and Immunity in Global Health Program of the RI-MUHC and an associate professor in the Division of Infectious Diseases at Âé¶čAV.
âPinpointing this gene, will also help scientists identify who else in the family is at risk, including newborn babies before they become sick.â
Gene with a link to Chromosome 21
The scientist says the knock-on from this discovery is the glimpse into whether it causes the immune deficiency reported in Down syndrome, which occurs as these individuals get older.
âThis gene is on Chromosome 21 and it turns out that Down syndromeâs patients, who have three Chromosomes of 21 (instead of the usual two), have a similar problem with their immune system. Weâre looking to see if this causes the immune deficiency reported in adults with Downâs syndrome,â says Dr. Vinh, whose study of genetic defects of the immune system has fueled his "medical detective" reputation.
A patient with similar symptoms to the âBubble Boyâ
Dr. Vinhâs discovery originated with the medical investigation of a 36-year-old male patient who had endured recurrent sinusitis and pneumonias, yeast infections and viral infections since childhood. Researchers used a state-of-the-art technique called âWhole Exome Sequencingâ inside Dr. Vinhâs laboratory to evaluate the patientâs genes and perform sophisticated analysis of his genes compared to that of his family members, to identify the abnormal gene that was responsible for his disease.
âAt the clinical level, previous evaluations did not look at all his symptoms in their entirety as one disease but as individual and unrelated problems. But once you start putting the abnormalities together, you see our patientâs case was similar to that of the âBubble Boy,â which was the most severe form. Our patientâs disease is in the same family of conditions but because he was an adult, nobody thought to explore this possibility,â says Dr. Vinh, who explains the âBubble Boyâ name was given to a young child in the Seventies who was forced to live in a sterile bubble from birth due to his severely weakened immune system.
âOnce we related our patient to the Bubble Boyâs disease, which we know is genetic, we discovered this new gene,â says Dr. Vinh, who collaborated with Dr. AndrĂ© Veillette, the Director of the IRCM Molecular Oncology Research Unit at the Montreal Clinical Research Institute (IRCM) in the study.
âWe are so relieved to finally receive a diagnosis, after so many years of doctors not knowing what was wrong with me, and with the research providing the potential for eventual treatment for me. And knowing that our children are not affected is a major comfort,â says the French-Canadian patient, who resides in Eastern QuĂ©bec with his wife and two young children.
Dr. Vinh has already received numerous requests from physicians around the world to test patients who may have the same medical condition diagnosed in his own patient, providing hope for both patients and their families.
About the study
âLoss of human ICOSL results in combined immunodeficiencyâ was written by Lucie Roussel, Marija Landekic, Makan Golizeh, Christina Gavino, Ming-Chao Zhong, Jun Chen, Denis Faubert, Alexis Blanchet-Cohen, Luc Dansereau, Marc-Antoine Parent, Sonia Marin, Julia Luo, Catherine Le, Melanie Langelier, Irah L. King, Maziar Divangahi, William D. Foulkes, Donald C. Vinh. DOI: 10.1111/1523-1747.ep12613748
Funding
La Fondation du Grand DĂ©fi Pierre Lavoie; Fonds de Recherche du QuĂ©bec - SantĂ© (FRQS); RI-MUHC (Merck Sharpe & Dohme award); Canadian Institutes of Health Research (CIHR); FDN-143338; Bristol-Myers Squibb; Âé¶čAV; CSL Behring Canada.
About the RI-MUHC
The Research Institute of the Âé¶čAV Health Centre (RI-MUHC) is a world-renowned biomedical and healthcare research centre. The Institute, which is affiliated with the Faculty of Medicine of Âé¶čAV, is the research arm of the Âé¶čAV Health Centre (MUHC) â an academic health centre located in Montreal, Canada, that has a mandate to focus on complex care within its community. The RI-MUHC supports over 460 researchers and close to 1,300 research trainees devoted to a broad spectrum of fundamental, clinical and health outcomes research at the Glen and the Montreal General Hospital sites of the MUHC. Its research facilities offer a dynamic multidisciplinary environment that fosters collaboration and leverages discovery aimed at improving the health of individual patients across their lifespan. The RI-MUHC is supported in part by the Fonds de recherche du QuĂ©bec â SantĂ© (FRQS). rimuhc.ca
Media contact
Paul Logothetis
Tel: 514-934-1934 ext.34319
Cel: 514-210-6376
paul.logothetis [at] muhc.mcgill.ca
Julie Robert
Communications Coordinator â Research
Âé¶čAV Health Centre
Cel: 514-971-4747
julie.robert [at] muhc.mcgill.ca
