Down Syndrome and Other Diseases

By Dr. Ananya Mandal, MDReviewed by Sally Robertson, B.Sc.

Individuals with Down syndrome suffer from several health problems as a result of their condition. While these problems may only be mild in some individuals, others experience more severe health conditions and require special medical care and support. Some of the health problems often faced by individuals with Down syndrome are described below.

Heart disorders

Around half of all babies with Down syndrome are born with a congenital heart defect and around 60% of those require treatment in hospital. In almost all (90%) cases, the defect is a ventricular septal defect or a hole in the septum that lies between the two ventricles of the heart.

The condition is commonly referred to as a “hole in the heart.” This leads to a build up of blood in at least one of the heart chambers, which means the heart has to pump harder to move blood through the organ.

Tetralogy of Fallot – This condition affects about 6% of people with Down syndrome and leads to poor oxygenation of the blood and breathlessness.

Patent ductus arteriosus – This is seen in around 4% of cases and refers to an abnormality of the ductus arteriosus. In healthy babies, the ductus arteriosus usually closes shortly after the child is born, but in this condition, the duct does not fully close and oxygenated blood seeps back through to the lungs rather than being pumped away from them. This places strain on the heart and lungs which then need to work harder to compensate.

Intestinal problems
Many individuals with Down syndrome experience intestinal problems. Examples include constipation, indigestion, diarrhea and obstruction of the bowel. Around 5% to 15% of people with the condition also develop coeliac disease. Some children may be born with a condition called imperforate anus (the absence of an anal opening) or Hirschsprung’s disease, which affects the large bowel’s ability to move feces along towards the anus.

Hearing problems
Hearing problems are seen in about half of all people with Down syndrome. Glue ear is one common condition, which refers to the accumulation of fluid in the middle ear that can muffle and distort the perception of sound.

Vision problems
About 50% of Down syndrome sufferers find they have visual disturbances such as a squint, lazy eye, short or long sightedness, cataract, keratoconus (thin and bulging cornea) and nystagmus (uncontrolled eye movements).

Increased risk of infections
Individuals with Down syndrome have underdeveloped immune systems and are more susceptible to infections, particularly pneumonia.

Thyroid problems
Thyroid problems occur in around 10% of those with Down syndrome, usually in the form of hypothyroidism. The underactive thyroid can cause problems such as lethargy, weight gain and delayed mental and physical responses. More rarely, individuals develop hyperthyroidism. Symptoms of an overactive thyroid include breathing difficulty, sleeping difficulty and hyperactivity.

Leukemia
Around 1% of those with Down syndrome develop acute leukemias.

Further Reading

• All Down Syndrome Content
• Down Syndrome - What is Down Syndrome?
• Down Syndrome Symptoms
• Down Syndrome Complications
• Down Syndrome Screening