Dark skin is more common in children, and research suggests that people with dark skin are more likely than others to have adverse health effects, according to a new study published in the New England Journal of Medicine.
Researchers at Johns Hopkins University studied more than 9,000 children ages 5 to 16.
They found that children with darker skin were more likely in the study to have poor school performance and a higher risk of being diagnosed with ADHD, anxiety disorders and depression.
“We know that darker skin color is associated with higher levels of genetic variations in the brain, which may contribute to the development of mental health disorders, and that darker individuals have higher rates of certain chronic diseases, such as heart disease, diabetes and cancer,” said study author Dr. Rebecca M. Krieger.
“For example, darker skin is associated to higher levels in a gene called TGF-beta, which is associated in part with a variety of health conditions such as diabetes, high blood pressure and cardiovascular disease.”
In the study, Kriege and her colleagues analyzed the genetics of more than 17,000 individuals from different parts of the world.
They then created a database of genes that appeared to be linked to the genetic makeup of individuals who had darker skin.
In particular, they focused on a gene known as SLC26A2, which encodes a protein known as TGFbeta.
The study found that darker people with SLC25A2 mutations had more of the protein in their blood.
“This is a gene with a major role in regulating the function of TGFβ,” said Krieged.
“It’s also known to have a role in the regulation of the immune system, and we wanted to understand whether SLC23A2 also had an effect on that function.
We found that there was a significant association between SLC24A2 mutation and increased risk of asthma and asthma-related asthma symptoms.”
A study published last year found that more than half of African Americans and Asian Americans had the gene mutation.
But the genetic difference in those two groups is largely genetic, and so the new study is the first to look at how it impacts a specific gene.
The researchers say the new research supports a recent study that found that white children with recessive mutations of SLC27A2 had a higher rate of asthma symptoms than their white counterparts.
“Our findings indicate that darker-skinned individuals are at increased risk for certain types of asthma, such the exacerbation of asthma-like symptoms, and for asthma-associated conditions such sleep apnea, asthma-promoting medications and increased rates of asthma in later life,” said lead author Drs.
Jessica Kriegel and Jennifer M. Schulz.
“Additionally, there are associations between SLL (small LDL particle size) and asthma and allergic diseases.”
This is the second study to link the genes SLC28A1 and SLC22A2.
The first study, published in December of 2015, found that the genes were linked to an increased risk in children with ADHD.
The new study looked at more than 13,000 people from the same population who had been followed since 2003.
The investigators found that SLC29A2 is a risk factor for asthma in children.
“In this study, we focused on SLC21A1 mutation, which appears to be associated with an increased susceptibility to asthma,” said Dr. Kriek.
“While we know that SLDL (small dense lipoprotein) is a major component of the inflammatory response, this study provides the first evidence that SLS (small-diameter lipoproteins) and SLSB (small scleractin) are also important components of the response to asthma.”
The authors say that these findings have implications for understanding how the genes are involved in inflammatory responses in the immune response.
“These findings have important implications for the understanding of the molecular mechanisms underlying asthma and the development and clinical treatment of asthma,” the researchers wrote.
“The results also suggest that there may be multiple pathways by which SLC18A1 mutations may contribute in exacerbating asthma-induced inflammatory reactions, which could be important in the prevention and treatment of this condition,” they added.
“Further studies will be needed to elucidate the mechanisms by which the SLC17A2/SLC27/SLSB/SLDL pathway may contribute and whether or not these pathways are associated with other conditions, such asthma or cardiovascular disease, as well as asthma itself,” said Schulz, lead author of the study.