By Doris Obinna [email protected] 08027048858
Among groups at higher risk of dying from COVID-19, such as people with diabetes, people with Down syndrome (DS) stand out: If infected, they are five times more likely to be hospitalized and 10 times more likely to die than the general population, according to a large United Kingdom study published in October.
Explaining the likelihood of the study, a family health physician, Dr. Gabriel Omonaiye, said, “I will not be surprise because of their vulnerability. Before now, people with Down syndrome tend to have shorter lifespan than the general population.”
According to him, there are factors within which may make it difficult for people with Down syndrome to adhere to COVID-19 protocols than the general population.
He said: “A person with Down syndrome has decrease immunity. So generally, on their own even before the advent of COVID-19, they had higher rates of infections like urinary track and skin infection etc because of their low level of immunity.
“Again, because of their low level of cognitive function, they may not be able to practice the necessary COVID-19 preventive measures such as; regular hand washing, physical distance, use of sanitisers and facemasks. In other words, their level of intelligent is lower than for the average population.”
According to the Centers for Disease Control and Prevention (CDC), Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small “packages” of genes in the body. They determine how a baby’s body forms during pregnancy and how the baby’s body functions as it grows in the womb and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby’s body and brain develop, which can cause both mental and physical challenges for the baby.
Mr Segun Oyeniran, who works with people with disability, further explained that intellectual disability is one of the problems with people with Down syndrome. “So ordinarily, they would find it difficult to understand what COVID-19 is all about not to talk of abiding by the protocols. It is only few of them that can have that understanding but may not have an in depth understanding of COVID-19 and the need to abide by the preventive measures as to safe guard themselves. In other words, the protocol makes no meaning to a lot of them.
“We already know that they are vulnerable and so we have to go extra miles and do extra things to ensure that they are protected while also protecting ourselves. We ensure that they don’t sit too close to one another, carry out temperature check every morning, wash their hands, and make hand sanitisers acceptable to them by sanitising their hand periodically. We also have different visual pills made available.
“And again, naturally, people with Down syndrome like to cuddle, embrace and hug people, so we try to let them understand that this is not the best of time to get attached to people physically. Once we notice anyone of them running temperature or perhaps with catarrh then, by ensuring that everyone is safe, we may call the attention of their parents or probably put them on medication. So far so good, God has been so kind.”
The World Down Syndrome Day (WDSD) is observed on March 21 every year. The day is marked to raise awareness about Down syndrome. The day was first officially observed by the United Nations (UN) in 2012. The date March 21 was chosen to observe the day as it signifies the uniqueness of the triplication (trisomy) of the 21st chromosome, which causes Down syndrome.
This year’s theme: “We CONNECT so that we can” #CONNECTb was decided by the UN. The idea behind this theme, according to the UN, is to demonstrate that it only takes a human being to connect with another and it is the connection between people that helps in the worst situations.
“Ever since the coronavirus pandemic hit the world, people and businesses have been terribly affected. But in these trying times, what all of us must remember is to take care of those suffering from Down syndrome and also ensure that they are not left alone.
“Due to the different pandemic guidelines in different parts of the world, most of the events, workshops, and discussions are taking place online. On the brighter side, this is also an opportunity for people to connect with each other on a global level. This is beneficial as one can come to know about the different challenges that people with Down syndrome face.”
Researchers suspect background immune abnormalities, combined with extra copies of key genes in people with DS who have three copies of chromosome 21, rather than the usual two, make them more vulnerable to severe COVID-19.
“This is a vulnerable population that may need protective policies put in place,” said a clinical epidemiologist at the University of Oxford’s medical school and senior author on the UK study, Julia Hippisley-Cox.
On December 2, the UK’s Joint Committee on Vaccination and Immunisation recommended prioritizing people with DS for speedy vaccination. But the more than 200,000 Americans with DS so far are not slated for early vaccination nor has the U.S. CDC included DS in its list of conditions it says boost the risk for severe COVID-19.
Experts say the typical anatomy of people with trisomy 21, including large tongues, small jaws, and relatively large tonsils and adenoids, along with lax throat muscle tone, helps explain their higher rate of respiratory infections in general. But genetics may also make them particularly susceptible to SARS-CoV-2, the pandemic coronavirus.
“Down syndrome individuals might be more susceptible to infection due to triplication of TMPRSS2,” Dierssen says.
“Immune system abnormalities likely add additional risk. In people with DS, T cells don’t develop properly, and levels of circulating B cells are low. So are levels of a key protein that prevents immune cells from attacking the body’s own tissues. In contrast, levels of potent, inflammation-inducing signalling proteins are high, contributing to a state of chronic inflammation even in the absence of infection, experts say.
“The cells of people with Down syndrome are constantly fighting a viral infection that does not exist,” says a genomicist at the University of Colorado’s Linda Crnic Institute for Down Syndrome, Joaquin Espinosa. That reflects a revved-up immune system that may tip people with trisomy 21 into the hyperinflammatory state that typifies severe and fatal COVID-19, he suggests.
Causes
The National Down Syndrome Society (NDSS), disclosed that regardless of the type of Down syndrome a person may have, all people with Down syndrome have an extra, critical portion of chromosome 21 present in all or some of their cells.
“This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome.
“The cause of the extra full or partial chromosome is still unknown. Maternal age is the only factor that has been linked to an increased chance of having a baby with Down syndrome resulting from nondisjunction or mosaicism. However, due to higher birth rates in younger women, 80 per cent of children with Down syndrome are born to women under 35 years of age.
“There is no definitive scientific research that indicates that Down syndrome is caused by environmental factors or the parents’ activities before or during pregnancy. The additional partial or full copy of the 21st chromosome, which causes Down syndrome, can originate from either the father or the mother. Approximately 5 per cent of the cases have been traced to the father.”
Types
The society for Down syndrome said there are three types of Down syndrome. People often can’t tell the difference between each type without looking at the chromosomes because the physical features and behaviours are similar. These include:
“Trisomy 21: About 95 per cent of people with Down syndrome have Trisomy 21. With this type of DS, each cell in the body has three separate copies of chromosome 21, instead of the usual two copies;
“Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3 per cent). This occurs when an extra part or a whole extra chromosome 21 is present, but it is attached or “trans-located” to a different chromosome rather than being a separate chromosome 21;
“Mosaic Down syndrome: This type affects about 2 per cent of the people with Down syndrome. Mosaic means mixture or combination. For children with mosaic Down syndrome, some of their cells have 3 copies of chromosome 21, but other cells have the typical two copies of chromosome 21. Children with mosaic Down syndrome may have the same features as other children with Down syndrome. However, they may have fewer features of the condition due to the presence of some (or many) cells with a typical number of chromosomes.”
How common is Down syndrome
According to CDC, approximately one in every 700 babies in the U.S. is born with Down syndrome, making it the most common chromosomal condition. About 6,000 babies with Down syndrome are born in the U.S. each year.
“In recent history, advances in medicine and science have enabled researchers to investigate the characteristics of people with Down syndrome. In 1959, the French physician Jérôme Lejeune identified Down syndrome as a chromosomal condition. Instead of the usual 46 chromosomes present in each cell, Lejeune observed 47 in the cells of individuals with Down syndrome. It was later determined that an extra partial or whole copy of chromosome 21 results in the characteristics associated with Down syndrome.
“In the year 2000, an international team of scientists successfully identified and catalogued each of the approximately 329 genes on chromosome 21. This accomplishment opened the door to great advances in Down syndrome research.”
Likelihood of child having Down
syndrome
Down syndrome, according to NDSS, occurs in people of all races and economic levels, though older women have an increased chance of having a child with Down syndrome. A 35 years old woman has about a one in 350 chance of conceiving a child with Down syndrome, and this chance increases gradually to one in 100 by age 40. At age 45, the incidence becomes approximately one in 30. The age of the mother does not seem to be linked to the risk of translocation.
“Since many couples are postponing parenting until later in life, the incidence of Down syndrome conceptions is expected to increase. Therefore, genetic counselling for parents is becoming increasingly important. Still, many physicians are not fully informed about advising their patients about the incidences of Down syndrome, advancements in diagnosis, and the protocols for care and treatment of babies born with Down syndrome,” NDSS further disclosed