Why Iceland has almost no genetic diseases

Iceland, an island nation with a population of only 350,000 people, has transformed into a real treasure trove for geneticists. Its geographical isolation, genetic homogeneity of the population, and carefully preserved genealogical records open unique opportunities for scientific discoveries. "Rambler" tells about the genetic characteristics of this northern country.

Genetic homogeneity and low prevalence of diseases

Iceland's population formed from a limited number of settlers, which led to a high degree of genetic homogeneity. This simplifies the identification of genetic factors associated with diseases. For example, thanks to this feature, researchers have been able to identify rare variants associated with the risk of various diseases, including cancer and osteoporosis.​

Additionally, Down syndrome has virtually disappeared among newborns in Iceland, which is associated with the widespread use of prenatal screening and subsequent parental choice. Parents are provided with information about the probability of chromosomal abnormalities in the fetus, including Down syndrome. If the diagnosis is confirmed, most parents decide to terminate the pregnancy.

This is a medical practice that exists in a number of countries, but in Iceland, the level of refusal to give birth to children with Down syndrome is particularly high. According to CBS News, almost 100% of such pregnancies end in abortion.

Increased risk of rare mutations

Despite the low prevalence of many genetic diseases, the Icelandic population is at risk for rare mutations. For example, a mutation in the TM2D3 gene was discovered, which increases the risk of developing Alzheimer's disease and is found in Iceland approximately ten times more often than in other European populations. This was reported in ScienceDaily.

A mutation in the LGR4 gene has also been identified, associated with an increased risk of osteoporosis and certain types of cancer. It turned out to be relatively common among Icelanders compared to other populations, which allows researchers to study its impact on health under the conditions of a "genetic magnifying glass".

In summary: Icelandic studies help identify both protective and harmful mutations, which can contribute to the development of new methods for diagnosing and treating diseases. Although this leads to a low prevalence of many diseases, there is an increased risk of rare mutations, which proves the need for continued research in this area.​