SNP Shot: Genomic Insights

Homocystinuria is a genetic condition where the body struggles to properly process certain amino acids, which are the building blocks of proteins.

Classic homocystinuria, the most prevalent type, is defined by features like increased height, nearsightedness (myopia), a displaced eye lens, an increased susceptibility to blood clots, and weak, fracture-prone bones (osteoporosis) or other bone-related issues. Some individuals may also experience developmental delays and learning difficulties.

Rarer forms of homocystinuria can lead to intellectual disability, poor growth and weight gain (failure to thrive), seizures, and motor skill problems. They can also cause megaloblastic anemia, a blood disorder characterized by a low red blood cell count (anemia) and abnormally large red blood cells (megaloblastic).

The symptoms of homocystinuria generally appear in childhood, although individuals with milder cases might not exhibit any signs until adulthood.

Inheritance:

Homocystinuria follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must be mutated for the disorder to manifest. Individuals with one copy of the mutated gene are carriers. While carriers typically don't exhibit symptoms, they each possess one copy of the changed gene. Although individuals with one altered and one normal copy of the CBS gene do not have homocystinuria, they are at a higher risk of vitamin B12 and folic acid deficiencies compared to those without a CBS gene variant.