Unraveling the complexity of vitamin B12 diseases

For more than 45 years, Dr. David Rosenblatt, senior scientist in the Child Health and Human Development Program at the Research Institute of the McGill University Health Centre and a professor in the Departments of Human Genetics, Medicine, Pediatrics and Biology at McGill University, has helped and studied patients with difficulty assimilating vitamin B₁₂, a critical organic compound only found in foods derived from animals; vegans must obtain it from supplements. Vitamin B₁₂ is essential for healthy functioning of the human nervous system and red blood cell synthesis, and a lack of vitamin B₁₂ can cause anemia, problems with the brain and other serious medical issues. Collaborating with international research teams, Dr. Rosenblatt has discovered new genetic diseases related to vitamin B₁₂ deficiency, by identifying genes that are involved in its metabolism.

Now, a new study that Dr. Rosenblatt co-authored with a team of lead researchers at Baylor College of Medicine sheds new light into the complexity of vitamin B₁₂ diseases. The scientists studied two rare inherited vitamin B₁₂ diseases that are clinically distinct from the most common genetic vitamin B₁₂ disorder, called cblC. Their work suggests that, in addition to the gene affected in the common vitamin B₁₂ disease, other genes are also affected, making a more complex syndrome. The study, published today in Nature Communications, searched for those genes and studied their function.

Working with mouse models, the team found that the genes involved in the more complex forms of the condition not only cause the expected typical cblC vitamin B₁₂ disease but also affect the generation of ribosomes, the protein-building machinery of the cell. The findings support reevaluating how to treat patients in the future and have implications for genetic counselling.

To learn more, read the full press release from Baylor.