Substantial iron buildup in certain parts of the brain could be principally responsible for developing movement disorders like Parkinson’s disease, according to a new study.

Hereditary hemochromatosis, a disorder caused by a gene mutation, leads to iron buildup that results in conditions like heart problems, liver disease and diabetes. Previous conflicting research suggested that the brain was spared from iron accumulation by the blood-brain barrier, a network of blood vessels and tissues.

But a new study published Monday in the 2022 online issue of JAMA Neurology showed evidence of substantial iron buildup in regions of the brain responsible for movement.

Researchers from the University of California San Diego, UC San Francisco, Johns Hopkins Bloomberg School of Public Health, and Laureate Institute for Brain Research found that the gene mutation responsible for hereditary hemochromatosis could be a risk factor for movement disorders, including Parkinson’s disease, which is caused by a loss of nerve cells that produce the chemical messenger dopamine.

The researchers also found that males of European descent carrying two gene mutations had the highest risk; the females did not.

"The sex-specific effect is consistent with other secondary disorders of hemochromatosis. Males show a higher disease burden than females due to natural processes, such as menstruation and childbirth that expel from the body excess iron buildup in women,” said first author Robert Loughnan, Ph.D., a postdoctoral scholar in the Population Neuroscience and Genetics Lab at UC San Diego.

The observational study analyzed MRI scans of 836 participants and found 165 were at high genetic risk for developing the condition. Based on the scans, the researchers found substantial iron deposits on motor circuits of the brain of high-risk individuals.

"We hope our study can bring more awareness to hemochromatosis, as many high-risk individuals are not aware of the abnormal amounts of iron accumulating in their brains," said senior corresponding author Chun Chieh Fan, MD, Ph.D., an assistant adjunct professor at UC San Diego and principal investigator at the Laureate Institute for Brain Research, based in Tulsa, Oklahoma.

According to Parkinson’s Foundation, approximately 60,000 Americans are diagnosed with Parkinson’s disease each year.

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