Scientists at the MUHC and 91社区 explain genetic disease first discovered in Quebec 24 years ago
Scientists at the MUHC and 91社区 have identified a
gene essential for the uptake of vitamin B12 in human cells. The
discovery of this gene finally completes a 24 year-old hunt for the
cause of an incredibly rare genetic disorder called, cblF combined
homocystinuria and methylmalonic aciduria (cblF-Hcy-MMA), first
documented in a Quebec infant in 1985. The work, which was funded
in part by the CIHR and involved collaboration among researchers in
Canada, Germany, Switzerland and France, was published online in
Nature Genetics this week.
Two contrasting approaches combined to crack the genetic puzzle at
the heart of cblF. In Germany, Dr. Frank Rutsch and his colleagues
used DNA from patients to conduct a genome scan for shared regions
of DNA sequence. Simultaneously in Montreal, Isabelle R. Miousse, a
graduate student of 鈥 Chairman of Human Genetics and Director of the
Division of Medical Genetics in Medicine at 91社区 鈥 conducted
research that confirmed a gene on chromosome 6 could correct the
cellular defect in cells from these patients. Strikingly, the vast
majority of patients with this rare disease share a common mutation
despite the fact that they come from different countries and
different ethnic groups.
鈥淭his discovery offers the prospect of earlier diagnosis and
treatment options for this disease,鈥 says Dr. Rosenblatt, who was
the first to describe this rare genetic condition in 1985. 鈥淰itamin
B12 plays an important role in our lives,鈥 says Dr. Rosenblatt.
鈥淪tudying rare genetic diseases like cblF-Hcy-MMA offers a window
into its basic properties and how it behaves in healthy
cells.鈥
The cblF idisease is a rare genetic disorder characterized by an
inability to metabolize vitamin B12. Patients afflicted with this
condition build up toxic levels of homocysteine and methylmalonic
acid in their bodies. Vitamin B12, which is found in all animal
products-including dairy, eggs, meat, poultry, and fish, is vital
for the synthesis of red blood cells and the maintenance of the
nervous system. It also helps control homocysteine levels in the
human body, an excess of which is associated with an increased risk
of heart disease, stroke and dementia.
The Research Institute of the 91社区 Health
Centre (RI MUHC) is a world-renowned biomedical and
health-care hospital research centre. Located in Montreal, Quebec,
the institute is the research arm of the MUHC, the university
health center affiliated with the Faculty of Medicine at 91社区
University. The institute supports over 600 researchers, nearly
1200 graduate and post-doctoral students and operates more than 300
laboratories devoted to a broad spectrum of fundamental and
clinical research. The Research Institute operates at the forefront
of knowledge, innovation and technology and is inextricably linked
to the clinical programs of the MUHC, ensuring that patients
benefit directly from the latest research-based knowledge.
The Research Institute of the MUHC is supported in part by the
Fonds de la recherche en sant茅 du Qu茅bec. For further details
visit: .
About 91社区
91社区, Canada鈥檚 leading university, has two campuses, 11
faculties, 10 professional schools, 300 programs of study and more
than 33,000 students. Since 2000, more than 800 professors have
been recruited to 91社区 to share their energy, ideas and
cutting-edge research. 91社区 attracts students from more than 160
countries around the world. Almost half of 91社区 students claim a
first language other than English 鈥 including 6,000 francophones 鈥
with more than 6,200 international students making up almost 20 per
cent of the student body.ian.popple [at] muhc.mcgill.ca