Almost all newborns have jaundice within the first few days of life. This yellowish tint becomes visible both on the skin and on the whites of their eyes. The cause is bilirubin, a product of the breakdown of the baby’s excess red blood cells.
In most cases, jaundice goes away on its own, within a week, but some babies need medical treatment. In some babies, jaundice can affect energy and appetite. And if the illness continues, high bilirubin levels can cause brain damage.
The variant that provides almost total protection
The study is based on the analysis of blood samples from nearly 30,000 newborns and their parents. About 2,000 babies developed jaundice.
- 1 variant, out of millions of genetic variants analyzed, appears to almost completely protect infants against jaundice;
- The genetic variant also appears to be linked to an increase in another enzyme, UGT1A1, which is important for the metabolism of bilirubin in the body;
- This enzyme, UGT1A1, converts bilirubin into a water-soluble variant, allowing the body to get rid of bilirubin;
- This effect on bilirubin metabolism is only observed in the intestines of babies, but not in the liver, yet it is the liver that is responsible for bilirubin metabolism in adults;
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This genetic variant is present in about 12% of babies born in Europe and the United States.
Lead author Dr Pol Solé Navais, a researcher at Sahlgrenska Academy explains: “The genetic variant encodes an enzyme that had not previously been linked to bilirubin metabolism. Although the enzyme itself does not protect against jaundice, this discovery has led us down an exciting avenue of research, opening new avenues for personalized medicine.”
The study thus designates a new therapeutic target et encourages us to decipher in more detail the activity of the UGT1A1 enzyme in the intestines of newborns.
