Apolipoprotein A-I deficiency

Apolipoprotein A-I deficiency is a metabolic disorder related to the lipoprotein and characterized by a complete absence of the apolipoprotein A-I. 

The disease has been identified and described in 30 families so far. It first translates into a low plasma HDL cholesterol level from birth. Clinical symptoms manifest at a later time, which varies greatly from patient to patient. Symptoms include corneal herniation, xanthomas, and early-onset coronary heart disease. Less common are neurosensory signs or multi-organ manifestations. However, in the worst case these can lead to lethal organ failure. 

The cause of the disease is mutations or deletions in the APOA1 gene (11q23-q24), which encodes the apolipoprotein A-I. The nature of the mutations determines the expression of the symptoms.