Recessive Genetic Diseases Account for About 20% of Infant Mortality

One of the main concerns of anyone who wants to start a family is that their children are born healthy. In this sense, many serious diseases have a known genetic basis and are often inherited disorders that come from totally asymptomatic couples.

“In this context, genetic screening of women and couples who want to become parents brings a new entity to the concept of family planning. ‘Prevention’ when addressing the desire to become pregnant is a key tool that makes preventive medicine a standard of guarantee and safety, with a clear goal: a healthy baby at home”, commented Dr. Josep Pla, head of IVI’s Reproductive Genetics Unit.

In figures, in developed countries, recessive disorders together account for about 20% of infant mortality and 10% of paediatric hospitalisations. Although individually rare, according to the World Health Organisation (WHO), at least 1 in 100 couples in the general population is at high risk of having a child with a severe genetic disorder.

“Thus, preconception genetic testing as a preventive tool aims to inform people about the risk of having children with autosomal recessive and X-linked recessive disorders, enabling informed decision-making about their reproductive choices. Preconception genetic testing as a widespread practice among women or couples considering starting a family would drastically reduce the prevalence of this type of hereditary disease”, added Dr. Pla.

In the last two decades, in the context of unprecedented advances in genomic technologies, more than 1,300 recessive inherited disorders with mild to severe impact on health and life expectancy have been identified. Among the most frequent diseases in the population – high frequency of carriers – we could highlight the following:

• Cystic fibrosis (1 in 25-30 people are carriers)
• Alpha and beta thalassaemia (1 in 25-30 people are carriers)
• Non-syndromic hearing loss (1 in 30-40 people are carriers)
• Spinal muscular atrophy (1 in 45 people are carriers)
• Congenital adrenal hyperplasia (1 in 50 people are carriers)

“Our goal is to achieve healthy babies, either among women and couples who need reproductive treatments to achieve their pregnancy or those who want to take advantage of the possibilities offered by science with genetic studies to ensure their reproductive results. Under this premise, at IVI we advocate offering genetic screening tests in assisted reproduction centres in a systemic way. In fact, in some countries preconception carrier screening is indicated to any couple wishing to become pregnant, through family medicine, as is the case in Israel, for example”, said Dr. Pla.

Everyone is a carrier of between 3 and 5 recessive genetic mutations, which does not mean they suffer from the disease, but if they get pregnant with another person with the same altered gene, there is a 25% risk that the children will suffer from this disease.

“In our awareness of this, we made the so-called genetic compatibility test available to our patients many years ago, thanks to which we can discover which mutations each individual has and whether there is a risk of transmission to offspring. Whatever the result, the genetic counselling service will explain to our patients the reproductive options available to them in order to achieve their objective with the highest guarantees. Furthermore, this test is compulsory for all our donors, in order to offer patients who make use of these donated gametes the greatest security in their processes”, explained Dr. Pla.

New horizons in Genetics

Genetics is here to stay. This is demonstrated by the ‘genetic revolution’ we have experienced in recent years, making the genetic counsellor a key figure in enabling the patient to make autonomous decisions.

“This revolution will not stop. The growth seen in genetic testing, coupled with the significant reduction in the price of these tests will make this possible. We cannot imagine a future of assisted reproduction without a strong influence from genetics. There is an increasing tendency to include genetic counsellors, as has been the case at IVI for years, to accompany and bring this type of information closer to the patient”, concluded Dr. Pla.

According to Dr. Pla, the future of genetics in reproductive medicine can be outlined along these 3 lines:

• It will continue to focus on the study of each case through genetic testing to find out the exact problem that stands between the patient and paternity/maternity, in order to be able to offer personalised treatment.
• The number of studies available before pregnancy will also increase, allowing for a robust model of preventive medicine. In this way, some diseases that until now had no known cause will begin to have an identified cause that helps to make reproductive choices.
• And finally, gene editing, which makes it possible to correct or alter an individual’s genetic information. This is a field that has shown promise for years, but has been held back, in part, by the legal and ethical considerations that have arisen around it.