SNP Shot: Genomic Insights

Transcobalamin deficiency is a condition that disrupts the body's ability to transport cobalamin (vitamin B12). We acquire cobalamin through our diet, primarily from animal-based foods like meat, eggs, and shellfish. When the body can't properly move cobalamin to where it's needed, cells become deficient in this essential vitamin. Cobalamin is vital for cell growth, division (proliferation), and DNA creation. A lack of cobalamin leads to growth problems, a reduced number of blood cells, and other symptoms that usually appear in infancy.

Early indicators of transcobalamin deficiency often include poor weight gain and growth (failure to thrive), vomiting, diarrhea, and mouth ulcers. The nervous system is affected, potentially leading to progressive leg stiffness and weakness (paraparesis), muscle twitches (myoclonus), or intellectual disability.

Megaloblastic anemia, a blood disorder characterized by a shortage of red blood cells and abnormally large red blood cells, is common in individuals with transcobalamin deficiency. They may also experience neutropenia, a deficiency in white blood cells, weakening the immune system. Reduced cobalamin levels within cells can cause a build-up of specific substances, resulting in metabolic disorders like methylmalonic aciduria or homocystinuria.

Inheritance:

Transcobalamin deficiency follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must have mutations for the condition to develop. Individuals with autosomal recessive conditions inherit one mutated copy of the gene from each parent, who are typically carriers without displaying symptoms themselves.