SCIENTIFIC BACKGROUND

ABCA1

Tangier disease is a very rare autosomal recessive disorder of high-density lipoprotein (HDL) metabolism characterized by an absence of mature HDL particles in plasma and lipid deposits in various parenchymal organs. Characteristic features include orange hyperplastic tonsils, splenomegaly, and recurrent neuropathies. Biochemically, plasma is found to contain only pre-β-1-HDL andhas an almost complete absence of HDL cholesterol (<5 mg/dl), as well as low apoAI, low cholesterol, and normal or elevated triglycerides. Tangier disease patients have a moderately increased coronary risk.

 

The disease is caused by pathogenic variants in the ABCA1 gene (ATP-binding cassette transporter 1), a membrane protein involved in cholesterol and phospholipid efflux from the cell. Due to ABCA1 dysfunction, nascent HDL particles cannot take up sufficient cholesterol and phospholipids from peripheral cells and are rapidly metabolized. Other monogenic diseases that lead to HDL particle maturation dysfunction and are therefore associated with HDL deficiency (hypoalphalipoproteinemia) (HDL-C < 10 mg/dl) are lecithin-cholesterol acyltransferase (LCAT) deficiency, partial LCAT deficiency (fish eye disease), and apolipoprotein A-I (apo A-I) deficiency. Apo A-I deficiency is also associated with an increased risk of coronary heart disease (CHD).

 

References
Shapiro M.D. 2018, Endotext [Internet] / Hooper et al. 2017, EJHG 25:e1 / Schaefer et al. 2016, Prog. Cardiovasc. Dis. 59:97 / Ramasamy I. 2016, Clin Chim Acta. 454:143 / Schaefer et al. 2016, Endotext [Internet]

GENES

ABCA1

ASSOCIATED TESTS

How to order

LATEST ARTICLES

Every year on April 25th, DNA Day celebrates the discovery of DNA’s double helix and the advances we’ve made in understanding genetics. D...

Read more

Neurodevelopmental disorders (NDDs) have diverse genetic origins, making diagnosis challenging. A new study analyzing over 1,100 pediatric patients f...

Read more

Colorectal cancer (CRC) remains one of the most prevalent and deadly cancers worldwide, with a significant number of cases presenting at an advanced ...

Read more

Carrier screening is a genetic test designed to identify whether an individual carries a gene with changes (mutations) associated with inherited diso...

Read more

Trisomy 13, also known as Patau syndrome, is a genetic condition in which cells in the body have three copies of chromosome 13 instead of two. The co...

Read more

The human brain develops through a complex series of events, with genes carefully regulating the formation of neurons and glial cells. A recent study...

Read more

Rare diseases affect between 300 and 400 million people worldwide – more than cancer and AIDS combined [1, 2], but despite this, many people face a...

Read more

Rosalind Elsie Franklin was a brilliant and meticulous research scientist whose interdisciplinary work made fundamental contributions to various area...

Read more

February, designated as Cancer Awareness Month, marks a time to reflect on the remarkable progress made in cancer research and to inspire hope for th...

Read more

Introduction Cardiovascular disease (CVD) is a major health issue as it remains a leading cause of death worldwide [1]. CVD is responsible for mor...

Read more