Paternal age and risk of genetic disease: a growing link
Important correlation between paternal age and the likelihood of passing on rare genetic diseases to offspring revealed
A recent study, the result of collaboration between the Bambino Gesù Pediatric Hospital in Rome and the University of Oxford, has revealed an important correlation between the paternal age and the likelihood of passing on some rare genetic diseases to the child. This discovery, published in the prestigious scientific journal The American Journal of Human Genetics, has aroused great interest in the world of medical research and has important implications for genetic counselling and family planning.
The study
Our genetic heritage, DNA, contains all the information necessary for the development and functioning of our organism. Genetic diseases are caused by alterations (mutations) of this genetic code. These mutations may be present at birth or occur during life. The study focused on mutations occurring in cells that give rise to sperm. As we age, these cells divide more frequently and, in the event of these divisions, DNA copying errors may occur, giving rise to new mutations.
The benefit of mutated cells
One of the most significant findings of the study was the identification of a mechanism that promotes the transmission of certain genetic mutations to the child. The researchers observed that some mutations give the cells which carry them a selective advantage, allowing them to multiply more rapidly than others. This phenomenon, known as “clonal expansion”, is similar to what happens in cancer cells and increases the likelihood that a harmful mutation will be passed on to offspring.
The transmission of genetic disease
These mutated cells lead to the transmission of genetic diseases in offspring. The study deepened this discovery, in particular by focusing on Myhre syndrome, a rare genetic disease caused by mutations in a specific gene called SMAD4. Researchers have shown that mutations in this gene activate a cellular signaling pathway which promotes cell proliferation, thus promoting clonal expansion.
The health implications
This discovery has important implications for public health and clinical practice. Firstly, it stresses the importance of considering paternal age as a risk factor for certain genetic diseases. Secondly, it provides new information on the molecular mechanisms underlying the transmission of genetic diseases, paving the way for the development of new diagnostic and therapeutic tools.
What does it mean for couples?
For couples who want to have a child, this discovery can be a source of concern but also an opportunity to make informed decisions. Genetic counselling can help couples to assess their personal risk and choose the options that are best suited to their situation.
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