What happens if ABCA1 does not function?

If ABCA1 (ATP-binding cassette sub-family A member 1) does not function properly, it can lead to impaired cholesterol and phospholipid efflux from cells, resulting in reduced formation of high-density lipoprotein (HDL) particles. This dysfunction is associated with an increased risk of cardiovascular diseases, as it can cause cholesterol accumulation in macrophages, leading to atherosclerosis. Additionally, mutations in the ABCA1 gene can result in conditions like Tangier disease, characterized by very low levels of HDL and associated health complications.