Raynaud’s phenomenon, in which parts of the body such as fingers and toes become cold or numb, is likely to be caused by two genes, a study published Thursday in the same journal found. nature communications found.
Experts said the findings, the largest genetic study of the disease to date, could lead to more effective treatments.
In people with Raynaud’s phenomenon, cold temperatures and stress cause small blood vessels near the surface of the skin to spasm, constricting them and restricting blood flow. According to , fingers and toes are most commonly affected. mayo clinic. The skin becomes white or blue and turns red when the attack subsides.
“It causes pain and numbness,” said Dr. Marie Gerhard Herrmann, an associate professor at Harvard Medical School and a staff physician at Brigham and Women’s Hospital who specializes in cardiovascular medicine. Gerhard Herrmann, who was not involved in the new study, added that during a seizure, he may not be able to move his hands as much as he would like.
Dr. Laura Hammers, a rheumatologist and associate professor at Johns Hopkins University, said that treatments for Raynaud’s disease are available, but they can have unwanted side effects.
“The main treatment currently is a class of drugs called calcium channel blockers,” said Hammers, who was also not involved in the new study. “Those treatments are pretty helpful.” But because they lower blood pressure, they can be a problem for healthy people, she says. Additionally, it may cause side effects such as constipation, dizziness, and headaches. cleveland clinic.
Raynaud’s disease occurs in 2% to 5% of the population, is more common in women, and comes in two forms.
Primary Raynaud’s disease is by far the most common and is typically diagnosed in teenage girls and women in their 20s, Gerhard Herrmann said. Its symptoms can often be managed simply by making lifestyle changes, such as avoiding colds and limiting stress. However, for some patients, the symptoms are so bothersome that they must take medication.
The genes identified in this study are associated with primary Raynaud’s disease.
Secondary Raynaud’s disease is rare, symptoms can be severe, such as ulcers and gangrene in the fingers, and often require medication. It occurs in people with autoimmune diseases such as scleroderma, which causes thickening and inflammation of the skin, and lupus, which causes inflammation throughout the body.
Raynaud’s disease runs in families and is hereditary. “About half of people with primary Raynaud’s phenomenon have a first-degree relative who also has Raynaud’s disease,” said Hammers, co-director of the John Hopkins Scleroderma Center.
A new study explains why.
Researchers in London and Berlin examined data on more than 440,000 people from the UK Biobank, a large database containing genetic and medical information. The team identified 5,147 cases of Raynaud’s disease, of which 68% were primary Raynaud’s disease. Another 439,294 records served as controls.
“We identified two different genes that represent two different mechanisms,” said one of the study’s lead researchers and the Institute for Health Data Modeling at Queen Mary University of London’s University Institute for Precision Healthcare. said Maik Pietzner, a professor at the university.
One genetic mutation affects how blood vessels narrow. People with this mutation have more specific receptors for hormones released when the body feels stressed or cold, he said. These hormones signal small blood vessels in the skin to constrict, allowing blood to flow from the extremities to the body’s vital organs. Another genetic mutation affects the dilation and relaxation of blood vessels.
The hope is that the discovery could lead to new treatments, such as the development of drugs that target this hormone receptor, Pitzner said. One existing drug, an antidepressant called mirtazapine, already acts on the receptor and could be repurposed for patients with Raynaud’s disease, he said.
“The important thing for patients is to find a cure,” he says.
Although the two gene mutations are associated with primary rather than secondary Raynaud’s disease, new drugs developed could help patients with both types, Hammers said.
The researchers noted that the study had limitations. For example, we relied on diagnosis codes in people’s electronic medical records, which are not always reliable. As a result, some cases of Raynaud’s disease may have been missed and others may have been misdiagnosed.
Additionally, all participants were of European descent, so the results cannot be generalized to everyone. More research is needed, the researchers wrote.
“They need to actually see people with other ancestry,” says Gerhard Hermann.
Still, this large-scale study is the first to identify the genetics underlying the condition. “Previous genetic studies at Raynaud Hospital have not been as convincing as this one,” Hammers said.
“This is a huge step forward,” she said.
