Health issues associated with Down’s syndrome

Down’s Syndrome, sometimes referred to as Trisomy 21, is one of the most common chromosomal conditions. In this article we take a look at the health issues and conditions that are commonly associated with Down’s syndrome for both children and adults.

What is Down’s syndrome?

Down’s syndrome is often characterised as having a full or partial extra copy of chromosome 21 and is sometimes referred to as Trisomy 21. It is one of the most common chromosomal conditions at birth and affects approximately 1 in 1,000 births worldwide. This means that each year in the UK, around 700 babies are born with Down’s syndrome.

(Source:  National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention)

The presentations of Down’s syndrome can vary drastically. Individuals with Down’s syndrome have mild to moderate intellectual disability, characteristic facial features, and may have treatable medical conditions, such as congenital heart defects, low muscle tone, and low thyroid levels.

Nevertheless, many individuals with Down’s syndrome lead healthy and active lives. As our understanding of Down’s syndrome continues to grow, the clinical and social management of the condition improves – allowing many individuals to have jobs, relationships and even live independently.

What are the health issues associated with Down’s syndrome for children?

The severity of Down’s syndrome can vary drastically, but all people with Down’s syndrome have some degree of learning disability.

There are also several medical conditions that are more common in people with Down’s syndrome, including problems with their heart, hearing, vision, bowel problems and an increased likelihood of infections. Some of these problems can be life-threatening and may require surgery.

Medical complications of Down’s syndrome in children can include:

• Heart problems – around half of children born with Down’s syndrome are affected by a heart condition
• Vision problems – more than half of children born with Down’s syndrome have impaired vision
• Hearing problems – up to three quarters of children with Down’s syndrome have some degree of hearing loss
• Gastrointestinal (GI) problems – GI defects are more common in children with Down’s syndrome and often present as digestive problems or coeliac disease
• Sleep disorders – children with Down’s syndrome are at an increased risk of sleep disorders such as obstructive sleep apnea
• Autism – children born with Down’s syndrome are more susceptible to Autism
• Immune disorders – children with Down’s syndrome may have an impaired immune system, making them more likely to catch infections and more prone to autoimmune disorders and some cancers
• Obesity – when compared to the general population, children with Down’s syndrome are more likely to be obese
• Spinal problems – due to differences in bone structure, some children with Down’s syndrome are at an increased risk of injury to the spinal cord
• Hypothyroidism – children with Down’s syndrome are more likely to have an underactive thyroid. This may present as weight changes, lethargy, and irritability
• Other problems – Down’s syndrome has also been associated with other disorders such as hypotonia (low muscle tone), dental problems, seizures, and disorders of the blood

What are the health issues associated with Down’s syndrome for adults?

Adults with Down’s syndrome are also at an increased risk of all of the health complications that are common in childhood. In addition, adults with Down’s syndrome are susceptible to other adult-onset health issues. These include:

• Dementia and memory loss – adults with Down’s syndrome may develop dementia at a younger age
• Premature aging – adults with Down’s syndrome tend to show signs of aging much earlier than expected. This includes premature difficulties with vision, hearing, as well as physical and cognitive signs of aging
• Mental health disorders – individuals with Down’s syndrome have an increased prevalence of mental health conditions such as ADHD, depression, anxiety, and obsessive-compulsive disorder
• High cholesterol, metabolic syndrome, and obesity – insulin resistance, issues with metabolism and obesity are common amongst individuals with Down’s syndrome
• Diabetes – people with Down’s syndrome are at an increased risk of type 1 diabetes mellitus

What is the life expectancy for people with Down’s syndrome?

The life expectancy for people with Down’s syndrome has increased dramatically as our knowledge and understanding of the condition has grown.

In 1960 the life expectancy of a person with Down’s syndrome was only 10.

Today, the life average expectancy of an individual with Down’s syndrome is almost 60 years, and this figure is continuing to climb.

Source: Down Syndrome Life Expectancy Is Higher, But Not For Everyone (nationwidechildrens.org)

How can I get Down’s syndrome screening during pregnancy?

A screening test for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome is available at 10-14 weeks of pregnancy.

The screening test that is most widely available is known as a combined test. The combined test comprises of a blood test and an ultrasound scan. The blood test looks at markers found in the blood that can indicate an increased chance of carrying a baby with a chromosomal disorder. The ultrasound scan is used to determine something known as the “nuchal translucency.” The results of both of these tests are used along with the age of the pregnant woman to determine the risk of carrying a foetus with Down’s syndrome, Edwards’ syndrome or Patau’s syndrome.

In the case of a high-risk result from the combined test, the pregnant woman will be offered another screening test or diagnostic testing, which may be an amniocentesis or chorionic villus sampling (CVS). Amniocentesis and CVS will provide a definitive answer as to whether or not the baby has Down’s syndrome, Patau’s syndrome or Edwards’ syndrome but, in rare cases, amniocentesis and CVS can cause a miscarriage.

To perform NIPT, CVS or amniocentesis, foetal DNA must be obtained for analysis. Foetal DNA is traditionally acquired through invasive sampling methods such as amniocentesis or CVS.

Amniocentesis involves a long, thin needle that is inserted through the abdomen (stomach) to obtain a sample for testing. For CVS, a needle is inserted into the womb to obtain a sample of cells. Both procedures are invasive and increase the risk of pregnancy loss. This increased risk of miscarriage is often a dilemma and is why many pregnant women choose to take a NIPT screening test privately, as it is available to all expectant mothers, irrespective of whether they were classified as high risk by the combined test.

The AlphaBiolabs IONA® NIPT test only requires a simple blood sample. This can be provided by any expectant mother in the first trimester, from 10+ weeks gestation, and isn’t restricted to those who received a high-risk result from the combined test.

The AlphaBiolabs NIPT test is a laboratory test that detects 97.2%-100% of trisomies in singleton and twin pregnancies. The AlphaBiolabs IONA® NIPT test can also provide foetal sex determination, which is not offered by the NHS. With results available in in 5-7 working days, you can get results much faster than the traditional testing pathway.

Traditional screening consists of multiple tests across the first and second trimesters, which can detect around 85% of babies with Down’s syndrome, and 80% of babies with Edwards’ or Patau’s syndrome.