Gene from Mom, gene from Dad…
Researchers of the Icelandic company Decode Genetics analyzed the previously unnoticed question of the connection of various diseases not just with certain gene variants, but with which of the two copies of the "disease gene" is active – paternal or maternal. To do this, the state of the DNA nucleotide sequence of 38,167 Icelanders and the morbidity of the examined and their parents were studied. The gene pool of Icelanders has changed little since the settlement of the island a thousand years ago, and the pedigree of almost every inhabitant of the island can be accurately traced back many generations.
As you know, people inherit one copy of each gene from each parent. In many cases, only one of the copies (the so-called genomic imprinting) is active (participating in protein synthesis). The regulation of gene activity in this case is due to the addition of certain chemical markers to the nitrogenous bases in the DNA, most often methyl groups. This attachment occurs in the early stages of intrauterine development and persists for life.
In the region of the genome selected for study, which is obviously susceptible to imprinting, there are seven genes, certain variants of the structure of which (alleles) are associated with various diseases. For genes associated with prostate cancer and heart artery disease, it was not possible to find a reliable relationship between the activity of paternal and maternal alleles. In the other five genes, scientists found mutations that exhibit opposite properties, depending on which parent the copy of the gene was obtained from.
One of the genes slightly increases the risk of developing breast cancer if inherited from the father, and has no effect on the likelihood of breast cancer or slightly lowers it if received from the mother. The other one contributes to the development of basal cell carcinoma, but only in the paternal version. But most of all, scientists were struck by one of the three genes associated with type 2 diabetes. A certain single nucleotide polymorphism in this gene has a huge and directly opposite effect, depending on which parent it is obtained from: people with this mutation inherited from their father have a 30% increased risk of diabetes compared to those who do not have this mutation. If the mother was the carrier of the same gene variant, the risk of diabetes is reduced by 10%.
The results of the work are published in Nature (Augustine Kong et al., Parental origin of sequence variants associated with complex diseases).
Portal "Eternal youth" http://vechnayamolodost.ru according to Reuters: Genetic gift from mom, genetic burden from dad17.12.2009