After reaching 30 years of age, some may lose their ability to speak.They typically do fairly well with social skills. Behavior problems are not generally as great an issue as in other syndromes associated with intellectual disability. In children with Down syndrome, mental illness occurs in nearly 30% with autism occurring in 5–10%. People with Down syndrome experience a wide range of emotions. While people with Down syndrome are generally happy, symptoms of depression and anxiety may develop in early adulthood.Children and adults with Down syndrome are at increased risk of epileptic seizures, which occur in 5–10% of children and up to 50% of adults. This includes an increased risk of a specific type of seizure called infantile spasms. Many (15%) who live 40 years or longer develop Alzheimers disease. In those who reach 60 years of age, 50–70% have the disease. Senses
Hearing and vision disorders occur in more than half of people with Down syndrome. Vision problems occur in 38 to 80%. Between 20 and 50% have strabismus, in which the two eyes do not move together. Cataracts (cloudiness of the lens of the eye) occur in 15%, and may be present at birth. Keratoconus (a thin, cone-shaped cornea) and glaucoma (increased eye pressure) are also more common, as are refractive errors requiring glasses or contacts. Brushfield spots (small white or grayish/brown spots on the outer part of the iris) are present in 38 to 85% of individuals.Hearing problems are found in 50–90% of children with Down syndrome.
Non-blood cancers
People with Down syndrome have a lower risk of all major solid cancers, including those of lung, breast, and cervix, with the lowest relative rates occurring in those aged 50 years or older. This low risk is thought due to an increase in the expression of tumor suppressor genes present on chromosome 21. One exception is testicular germ cell cancer which occurs at a higher rate in Down syndrome. Endocrine
Problems of the thyroid gland occur in 20–50% of individuals with Down syndrome. Low thyroid is the most common form, occurring in almost half of all individuals. Thyroid problems can be due to a poorly or nonfunctioning thyroid at birth (known as congenital hypothyroidism) which occurs in 1% or can develop later due to an attack on the thyroid by the immune system resulting in Graves disease or autoimmune hypothyroidism. Type 1 diabetes mellitus is also more common. Gastrointestinal
Constipation occurs in nearly half of people with Down syndrome and may result in changes in behavior. One potential cause is Hirschsprungs disease, occurring in 2–15%, which is due to a lack of nerve cells controlling the colon. Other frequent congenital problems include duodenal atresia, pyloric stenosis, Meckel diverticulum, and imperforate anus. Celiac disease affects about 7–20% and gastroesophageal reflux disease is also more common. Teeth
People with Down syndrome tend to be more susceptible to gingivitis as well as early, severe periodontal disease, necrotising ulcerative gingivitis, and early tooth loss, especially in the lower front teeth.