Abetalipoproteinemia

Background and History: 

This disorder was formerly called Bassen-Kornzweig disease after Frank Bassen, a Canadian-born internist and Abraham Kornzweig, a New York ophthalmologist, described it in 1950.  It has also been called acanthocytosis from the peculiar shape of the red blood cells in this disorder.  It is a disorder of lipid metabolism.

Clinical Correlations: 

This disorder of lipid metabolism has widespread effects throughout the body.  One of the earliest symptoms is nightblindness due to damage to the rod receptors in the retina.  Eventually, the cones are damaged as well and the retina in the back of the eye has patchy pigmentation.  The visual fields are severely restricted so that side vision is narrowed.

Changes in the circulating blood limit the absorption of fat soluble nutrients, including vitamins A and E, leading to deficiencies that impact other parts of the body.  Fat molecules such as cholesterol, triglycerides and others are low in number.  Stools become highly fatty and red blood cells assume a characteristic shape with 'burrs' on the surface.   Scarring of the liver (cirrhosis) and eventually failure of this organ are common.  Fats are important to nerve insulation and function and in their absence some patients experience neurological symptoms such as unsteadiness.

Genetics: 

This is an autosomal recessive disorder resulting from the inheritance of a mutation from clinically normal parents who both carry it.  It is generally not passed on directly from one generation to the next but parents who are related are more likely to carry the same mutation and the risk of inheriting this disorder is therefore high (25% for each child).

Diagnosis and Prognosis: 

An internist and/or hematologist usually makes this diagnosis but the appearance of the retina together with characteristic symptoms of night vision difficulties may suggest it to your eye doctor.  No cure is available but it has been reported that large doses of vitamin A together with vitamin E can result in some improvement.

Additional Information