Researchers from the University of Cambridge and colleagues from Finland and Germany found that about one in five hundred men have an extra sex chromosome that increases their risk of type 2 diabetes and other diseases. They reported this in a journal article. Genetics in Medicine.
Researchers analyzed records from the UK Biobank repository of medical and genetic information from more than 200,000 British men aged 40-70. Of these, 356 had an extra X or Y sex chromosome. Because the UK Biobank has data on healthier people than the general population, researchers estimate that one in 500 men has an extra chromosome.
Sometimes, if a man is being examined for delayed puberty or infertility, an extra sex chromosome is detected by doctors, but in most cases, the men don’t know their characteristics, the authors of the study note.
Further analysis showed that men with the XXY genotype had a four-fold higher risk of infertility and a three-fold higher risk of delayed puberty. They also had significantly lower testosterone levels. Males with the XYY genotype did not have reproductive problems.
Men with an extra sex chromosome were three times more likely to suffer from type 2 diabetes, six times more likely to have thrombosis, three times more likely to experience a pulmonary embolism, and four times more likely to have chronic obstructive pulmonary disease.
“We will need more research to assess whether there is an additional benefit to broader screening for chromosomal abnormalities in the general population, but it has the potential to provide early intervention that could prevent the development of related diseases,” the authors wrote.