SNP Shot: Genomic Insights

Abetalipoproteinemia is a genetic disease that disrupts the body's ability to absorb fats and certain vitamins from food. This malabsorption leads to a deficiency in fat-soluble vitamins A, E, and K, causing many of the characteristic signs and symptoms. The primary areas affected by this condition are the digestive system, eyes, nervous system, and blood.

The initial signs of abetalipoproteinemia typically appear in infancy. These early indicators often involve a failure to thrive, characterized by insufficient weight gain and growth, along with diarrhea and stools that are fatty, bulky, and foul-smelling (steatorrhea).

As individuals with abetalipoproteinemia grow older, they can develop neurological complications. These may include problems with coordination and balance, leading to ataxia. Other neurological issues can manifest as a loss of reflexes, difficulty speaking clearly (dysarthria), tremors or involuntary movements (motor tics), loss of sensation in the extremities (peripheral neuropathy), and muscle weakness. These muscle problems can impact skeletal development, potentially resulting in an abnormally curved lower back (lordosis), kyphoscoliosis (a combination of rounded upper back and sideways curvature), high-arched feet (pes cavus), or clubfoot (an inward and upward turning of the foot).

Eye problems are also common in this condition. A progressive eye disease called retinitis pigmentosa can develop, where the light-sensitive retina at the back of the eye deteriorates, potentially leading to vision loss, even complete blindness. Additional eye-related symptoms can include involuntary eye movements (nystagmus), misaligned eyes (strabismus), and weakness of the eye muscles (ophthalmoplegia).

Hematological abnormalities are frequently observed in individuals with abetalipoproteinemia. They often have anemia (low red blood cell count) characterized by abnormally shaped, star-like red blood cells (acanthocytosis). Furthermore, they may experience difficulties with blood clotting, leading to abnormal bleeding. In some instances, a condition known as fatty liver can develop, which can result in liver damage.

Inheritance:

Abetalipoproteinemia follows an autosomal recessive inheritance pattern. This means that an individual must inherit two copies of the mutated gene (one from each parent) to develop the condition. Parents who each carry one copy of the mutated gene are typically carriers and do not exhibit symptoms of the disease.