Introduction
HDL carries phospholipids and other specific fats from the body's tissues to the liver, where they are excreted from the blood. Additional Tangier disease symptoms include enlarged, orange-colored tonsils, neuropathy, mild hypertriglyceridemia, increased blood fat levels, and mild hypertriglyceridemia. An accumulation of fatty deposits and scar-like tissue in the lining of the arteries is a common complication for affected people. Other characteristics of this condition may include type 2 diabetes, an enlarged liver (hepatomegaly), a clouding of the clear covering of the eye, an enlarged spleen (splenomegaly), and corneal clouding.
What Is Tangier Disease?
High-density lipoprotein (HDL) insufficiency or absence in Tangier illness causes tissue accumulation of cholesteryl esters throughout the body, especially in the reticuloendothelial system. Hepatosplenomegaly, hyperplastic yellow-orange tonsils, and peripheral neuropathy, which may be relapsing-remitting or chronic progressive, are the main clinical symptoms of Tangier's illness. Rarer side effects could include corneal opacities, which typically do not impair vision, early atherosclerotic coronary artery disease (usually not before age 40), and mild hematologic manifestations like reticulocytosis, mild thrombocytopenia, stomatocytosis, and hemolytic anemia. Tangier illness can manifest clinically in various ways, with some infected people simply exhibiting metabolic disturbances.
What Are the Causes of Tangier Disease?
The ABCA1 gene a person receives from their parents is how they get Tangier illness. A flaw in the gene's instructions prevents the body from transferring cholesterol from the cells into HDL when it is abnormal. Bad cholesterol is delivered to the liver by HDL, which then eliminates it. The person will develop Tangier disease if both parents pass them a defective ABCA1 gene. If the person gets an abnormal gene from only one parent, they become a carrier for Tangier. They may not show signs of Tangier but still can have low HDL. If a child is born to two carriers of the aberrant gene, that child, regardless of gender, may:
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Have a 25% chance of having Tangier disease.
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Be a carrier - 50% chance.
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Not inheriting an abnormal gene from either parent - 25% chance.
Which Protein Is Deficient in Tangier Disease?
In Tangier disease, the person will have very little apolipoprotein A1 (ApoA1). This protein is a component of HDL, which is similarly insufficient in those with this condition.
What Are the Clinical Characteristics of Tangier Disease?
Tangier illness is characterized by a significant lack of high-density lipoprotein (HDL) in the bloodstream. This causes tissue accumulation of cholesteryl esters throughout the body, especially in the reticuloendothelial system. According to Mercan et al. (2018), neuropathy can have a relapsing-remitting or chronic progressive clinical history. Nevertheless, the clinical manifestation of Tangier's sickness varies, and some affected people merely exhibit biochemical disturbance.
How Is Tangier Disease Diagnosed, and What Are the Tests Carried?
After performing a physical examination and running blood tests to check for HDL and one of its proteins, the doctor can determine whether the person has Tangier disease. The diagnosis can be supported by genetic testing. The doctor can collect a tissue sample (biopsy) from several body areas if the person cannot receive a genetic test.
The following tests help to diagnose Tangier disease:
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Eye exam.
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Nerve and muscle studies (electromyograms).
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Echocardiogram.
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Exercise stress test.
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CT angiogram of the heart.
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Ultrasound of carotid arteries.
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Ultrasound of abdomen.
How Is Tangier Disease Treated?
Treatment for manifestations includes tonsillectomy for people with airway obstruction or mass symptoms, temporary bracing (like an ankle-foot orthosis), exercise, and corneal transplantation for people with corneal opacities that make it difficult to go about daily activities. Standard care is also provided for people who have coronary artery disease, hepatosplenomegaly, severe hemolytic anemia, and severe thrombocytopenia. Since there is no cure for Tangier disease, efforts are being made to raise HDL through dietary changes, maintaining a healthy weight, quitting smoking, regular aerobic exercise, and replacing saturated fatty acids with monounsaturated fats. These treatments might help with the symptoms, particularly with peripheral neuropathies. Lipid-lowering medications, including statins, niacin, and fibrates, can be administered either alone or in combination. However, there is no conclusive evidence that drug therapy to target low HDL cholesterol and optimize LDL levels is beneficial.
Future treatment strategies may involve increasing hepatocytes' absorption of cholesterol or decreasing HDL metabolism. This can be accomplished through targeted gene therapy, which results in ABC1 overexpression and an increase in cholesterol uptake by cells.
What Should a Person With Tangier Disease Eat?
One can increase the HDL (good cholesterol) and decrease the LDL (bad cholesterol) with some foods.
These consist of:
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Fatty fish.
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Avocados.
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Extra virgin olive oil.
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Beans.
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Entire grains.
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Nuts.
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Fruits with a high fiber content.
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Flax and chia seeds.
What Is the Differential Diagnosis of Tangier Disease?
The differential diagnosis includes hereditary Apolipoprotein A-I deficiency, LCAT deficiency, and secondary reasons for abnormally low levels of HDL cholesterol, such as medicines retinoids, androgenic steroids, paradoxical response to fibrates, liver failure, or cancer. A plasma lipoprotein profile may be used to distinguish TD from other non-uniform demyelinating polyneuropathies when neuropathic symptoms are present, especially if they are prevalent in the upper extremities.
What Is the Prognosis of Tangier Disease?
The advancement of peripheral neuropathy and atherosclerosis is the key factor determining the prognosis for Tangier disease, which is often good. Tangier disease patients are moderately more likely to develop coronary artery disease, but this condition is treatable with standard preventative medications.
Conclusion
The Tangier disease can affect various body parts, and has an autosomal recessive pattern. So it is best to have regular checkups for those areas. It is clinically characterized by enlargement of lymph node, spleen, liver, and tonsils associated with peripheral neuropathy in adults and children. To keep track of the various Tangier disease-related problems, one might need to visit multiple healthcare professionals.
