Screening

Diagnostic testing is an important line of defense against sexually transmitted infections (STIs), blood-borne diseases and infectious diseases. The wealth of information we can gather from a small sample is truly astonishing. It can lead to behaviour change, which can keep a person healthy and out of hospital, and it can help determine the course of medicine that would best reveal an imminent threat and lead to a life-saving decision.

Every parent-to-be hopes for a healthy baby. Whether trying to get pregnant or pregnant already, there are likely to be some concerns such as infertility, preeclampsia and Down syndrome.

The good news is that genetic tests are available that can equip couples and their doctors with the information required to help predict and manage many of these conditions.

Carrier screening is a type of genetic test to help determine whether an individual is a carrier of a harmful variant of a gene. This type of testing is generally for recessive disorders, in which both copies of a gene (one inherited from the mother, and the other from the father) are harmful. These disorders are usually passed on by two carriers, whose health is rarely affected as they each have one good gene copy.1 These women and men are likely asymptomatic and may not even know they are carriers.

Some examples of recessive disorders include sickle cell anaemia, cystic fibrosis, and Tay Sach’s disease.If you have a family history of a genetic disorder or you're in an ethnic group with a high risk of a specific genetic disorder, carrier screening before having children or during pregnancy can help determine the chances of having a child with a genetic disorder.

There are more than 200 million pregnancies annually worldwide.2 The mean age of childbearing varies greatly around the world.3 However, the average age at which women give birth has increased in most OECD countries and now stands at 30 or above.4

The risk of trisomy 21 (Down syndrome) is directly related to maternal age.5  Pregnant women are routinely encouraged to be screened for Down syndrome, as well as Edward’s Syndrome and Patau syndrome. One in 20 women receive a false positive result with a traditional screening test.6 However, a simple, non-invasive cell-free DNA-based blood test that can be administered as early as 10 weeks in pregnancy has been shown to identify greater than 99% of cases. Its false-positive rate is less than 0.1%.7 This test limits the number of unnecessary invasive procedures such as amniocentesis, which is associated with a risk of miscarriage.

This simple maternal blood test can provide information to healthcare providers and expecting parents about their pregnancy. It examines the developing baby’s DNA in the pregnant woman’s blood to provide accurate information about the likelihood for the most common chromosomal conditions and the foetal sex.  Results and counselling resources can help expectant parents plan and prepare next steps.

Every year, millions of newborn babies around the world have a few drops of blood taken from their heel to screen for a number of rare conditions. Carried out within a few days of birth, the screening is designed to identify conditions for which a clinical diagnosis may not be possible at such an early stage, but where early detection and treatment can save lives and potentially prevent symptoms of disease from developing.

Spinal muscular atrophy (SMA) is a genetic disease affecting the central nervous system, peripheral nervous system, and voluntary muscle movement (skeletal muscle). Nerve cells that control muscles are located in the spinal cord, which accounts for the word spinal involvement. SMA impacts the muscles, which don’t receive signals from nerve cells. Atrophy means getting smaller, which is what happens to muscles when they’re not stimulated by nerve cells.

Despite SMA meeting the World Health Organization's criteria for inclusion in newborn screening programmes, many babies in some countries across Europe are not screened.  Without screening for SMA at birth, the chance of early diagnosis is missed and the potential to introduce the best possible medical care with the aim of preventing the disease is lost.

Now, the European Alliance for Newborn Screening for Spinal Muscular Atrophy, founded by SMA Europe in August 2020, is calling for change. The Alliance recently published a new whitepaper Spinal Muscular Atrophy: screen at birth, save lives, outlining the need for the inclusion of SMA in newborn screening programmes in all European countries by 2025.

In the US, around 70% of newborns are already screened for SMA and progress is also being made in Europe with some European countries adopting screening. SMA has been approved for the national newborn screening programmes in the Netherlands, Germany, Norway, Serbia, Poland and Slovenia, and is currently awaiting implementation in all six countries.

A pilot trial in Germany, which started in 2018, is showing the benefits of newborn screening for babies with SMA and their families. About 180,000 babies were screened in the first 14 months of the trial, with 25 identified as having SMA. Early results show that all the children who went on to receive SMA-targeting treatment before clinical symptoms became apparent are showing near-normal development.8

As well as advocating at the European level, Alliance members are organising activities in their respective countries to request that health regulators evaluate adding SMA to newborn screening programmes. Applications have now been submitted to regulators in Austria, Denmark, Finland and Sweden and further pilot studies are either underway or being planned in a number of other countries. You can use this interactive map to find out the status of newborn screening for SMA in your country. 

As a founding member of the Alliance, which also includes European patient organisations, academics and other members of the pharmaceutical industry, Roche is proud to be part of this committed group helping to advocate for the needs of the SMA community. The publication of the Alliance’s whitepaper is an important step in working towards all European states introducing routine screening for SMA in newborns.

References

6. ACOG Committee on Practice Bulletin No. 163. Obstet Gynecol. 2016 May;127(5):e123-37

7. Norton ME et al. N Engl J Med. 2015;372(17):1589-1597.