The human body needs copper for many functions, including energy regulation, formation of connective tissue, and brain and nerve function. Changes, or mutations, in certain genes can lead to abnormal levels of copper in the body, which can have severe consequences if left untreated. Excess amounts of copper are toxic, and copper deficiencies can cause serious problems, including developmental delays, seizures, failure to thrive, and bone weakness. Some disorders are associated with low levels of ceruloplasmin, a copper-containing protein that transports copper in the blood.
Recently, researchers—including those in the Unit on Human Copper Metabolism within the Division of Intramural Research Molecular Medicine Program—studied five children from four unrelated families in Tunisia, Turkey, Saudi Arabia, and New Zealand who had abnormally low levels of copper in their blood and very low or undetectable amounts of ceruloplasmin. The patients displayed unique symptoms, including cataracts, hearing loss, brain abnormalities, and severe developmental delays. None of the patients could sit or walk, and none learned to speak. All of the patients died before the age of 6, even though three of them were treated with copper.
The scientists discovered that the five patients had mutations in a gene called SLC33A1 that normally codes for a protein called AT-1, a highly conserved acetylCoA transporter required for acetylation of multiple gangliosides and glycoproteins.
This study provided new insights into the critical function of AT-1, including its role in copper metabolism. Further research is needed to explore the role of AT-1 in brain metabolism and function and to develop treatments to prevent neurodegeneration and premature death in patients who have an AT-1 deficiency (PMID: 22243965).