Medical Concerns Associated with Down Syndrome

This material adapted from: Patterson, Bonnie (2003). "Down Syndrome Medical Issues Research." PowerPoint Presentation given at Healthcare Symposium. Shriner's Hospital, Lexington, Kentucky, June 21, 2003.

Persons with Down syndrome are at an increased risk for a number of associated medical concerns, the most significant of which are outlined below.

Behavioral Concerns
Children with Down syndrome all have their own unique personalities. Historically persons with Down syndrome have been stereotyped as having placid, amiable, dispositions. Recent studies reflect much more variety in temperament. An easy temperament alone, however, does not preclude development of conduct disorders. Any child or person may develop negative behaviors in certain situations/environments. No area of problem behavior seems to be specific to Down syndrome. Conduct disorders are the most frequently reported, with an incidence of between 11 and 12 percent. Difficult behavior may be precipitated and/or exacerbated by communication difficulties. It is important for clinicians to remember that although certain behaviors may appear immature for chronological age, they may not be immature for developmental age. It is best to consult a professional/therapist experienced in developmental disabilities when evaluating behavioral issues.

Cardiac Conditions
Forty-six to sixty-two percent of persons with Down syndrome are born with some form of cardiac defect. The most common is Atrioventricular Septal Defect (59%), followed by Ventricular Septal Defect (19%), Atrial Septal Defect (9%), Tetralogy of Fallot (6%), Patent Ductus Arteriosis (4%), and other cardiac abnormalities (3%). Significant defects are typically discovered and repaired during the first year of life. Despite this early intervention, some children with such history may require continuing cardiac care throughout their lives. Additionally, recent studies have suggested that children and adolescents with Down syndrome frequently demonstrate mitral valve prolapse or insufficiency, and/or atrial regurgitation. Antibiotic prophylaxis is recommended for these individuals prior to any surgical or dental intervention.

Depression
Persons with Down syndrome are just as susceptible to depression as the general population. Specifically, the incidence of depression in persons with intellectual disability in particular has been estimated at 6 to 7%.
Depression can occur as a result of current stress (acute), such as the death of a family member, leaving school, loss of siblings for college or home, or illness. Depression may also develop as a more chronic condition. A recent history of the person's life is necessary to define the problem, if possible, and identify available support systems. Mental health assessment must accommodate the individual's specific cognitive/developmental level.

It is important that any of the signs and/or symptoms of depression be closely assessed to determine if they are symptoms of a biological/medical condition (e.g., seizures, hypothyroidism ) or a condition in itself (i.e., depression). Possible signs and/or symptoms of depression include withdrawal, sadness, sleep disturbances, behavioral changes (either quieting or aggressive), weight loss or gain, recurrent thoughts of death, lack of energy and/or feelings of worthlessness. Often the diagnosis of depression is missed because the family is told that the particular signs/symptoms are just "Down syndrome." Signs and/or symptoms also might be misinterpreted as dementia or Alzheimer's disease. It is important when symptoms are present to consult a therapist experienced in the treatment of individuals with developmental disabilities. Timely treatment may prevent or diminish the need for inpatient service.

Many physicians, psychologists and other mental health professionals currently have had little training in the relationship of psychiatric conditions to intellectual disability, leaving room for missed or misdiagnosis. The clinical presentation of depression in persons with Down syndrome may be quite different from someone without a cognitive deficit.

As the person with Down syndrome ages, mental function and social support may decrease, creating an opportunity for depression to occur. Adults with Down syndrome may experience isolation, changes in residence, and a lack of social opportunities and adaptive skills. All of these factors contribute to decreased self-esteem, an inability to care for themselves, and depression. It is often the case that adults with Down syndrome lack the opportunities to make their own decisions in areas where they are capable (e.g., social activities, hair style, clothing choice, etc.). They are often treated as children and thus feel they have little, if any, control over their lives. Additionally, individuals who care for adults with Down syndrome may overlook support systems, over-protect the person, and/or inappropriately take punitive actions toward the person with Down syndrome.

Dental Defects
Dental abnormalities are common in persons with Down syndrome as well. Common problems include delayed eruption of primary teeth, misshapen or missing teeth, delayed loss of primary teeth, narrow palate, bruxism (grinding one's teeth), and periodontal disease. In addition, a small oral cavity is often seen in young persons with Down syndrome, potentially resulting in overcrowding of teeth and possible malocclusion. Orthodontic consultation may be required.

Dermatological Disorders
Skin problems are common in young people with Down syndrome. These may in part be related to immunologic factors (as in alopecia). Skin texture may be dry and rough. Up to 70% of individuals with Down syndrome are affected by xerosis (abnormally dry skin) by the teenage years. Hyperkeratotic lesions, elastic tissue defect, and alopecia areata are not uncommon. Localized hyperkeratotic lesions frequently occur on the anterior thighs, ankles, and wrists. Follicular skin infections of the buttocks, thighs, and perigenital area are more likely to occur in adolescents with Down syndrome. These infections may progress to abscess if left untreated. Fungal infections of the feet are frequently seen in patients with Down syndrome as well. Healthcare counseling should address preventative measures such as good hygiene, weight control, use of antibiotic ointments and emollients.

Gastrointestinal Disorders
Five percent of persons with Down syndrome experience gastrointestinal abnormalities. Included in this five percent are Duodenal Stenosis/Atresia (50%), Imperforate Anus (20%), Hirschsprung Disease (10%), Tracheoesophageal Fistula (9%), Pyloric Stenosis (6%), Malrotation (4%) and other gastrointestinal abnormalities (1%).

Immunological Disorders
Persons with Down syndrome are at an increased risk for several immune / infectious disorders, including juvenile rheumatoid arthritis, alopecia areata, celiac disease, deficiencies of cellular and humoral immunity, immunoglobulin deficiencies (such as low IgG Subclasses 2 & 4 , with elevated 1 & 3, found in individuals with serious pyogenic infections), and frequent ENT infections such as nasopharyngitis/sinusitis/otitis media. Thyroid dysfunction in Down syndrome may be related to autoimmune factors as well.

Musculoskeletal Conditions
Persons with Down syndrome are at high risk for musculoskeletal abnormalities, including ligamentous laxity and atlantoaxial instability. In the latter, excess mobility of the articulation of C1 (atlas) and C2 (axis) occurs. Fifteen percent of individuals with DS develop atlantoaxial instability. Of these 1-2% will develop subluxation and cord compression in this area. Clinicians should note that there is a higher incidence of individuals developing atlantoaxial instability during the rapid growth of adolescence. Cervical evaluation via x-ray is thus in order. Patients (and parents of children) exhibiting clinical atlantoaxial instability should be counseled to avoid contact sports, diving, trampoline exercises and/or other activities which may place undue stress on the neck area. Occasionally surgical stabilization of the atlas and axis may be required to prevent neurological compromise from spinal cord compression.

Ophthalmologic Disorders
Ophthalmologic disorders are very prevalent among individuals with Down syndrome. Of these the most common is strabismus, affecting 23 - 44 percent of individuals with Down syndrome. Amblyopia (decreased vision in one eye) is also common, but less frequent, occurring approximately 12% of the time. Cataracts also occur more frequently in individuals with Down syndrome. Although usually considered an issue affecting mature adults, cataract formation typically begins in adolescence, possibly as a result of the early aging process typically seen. Additionally, 5 to 8 percent of individuals are affected by keratoconus, or an anterior bulging of the cornea. Keratoconus is the second most common cause of blindness in individuals with Down syndrome. Blepharitis (inflammation of the eyelids) is also relatively common among adolescents, as are nasolacrimal duct stenosis and nystagmus. Refractive errors are also often present which may be easily corrected by optical lenses. Due to the increased incidence of these disorders in persons with Down syndrome, a thorough ophthalmologic exam is recommended with each check up.

Thyroid Dysfunction
Thyroid disorders are prevalent in persons with Down syndrome, with hypothyroidism occurring much more frequently than hyperthyroidism. Autoimmune factors may play a role in the etiology of hypothyroidism in Down syndrome, although the exact relationship is not completely understood. Studies have demonstrated that thyroid hormone levels may gradually decrease during the adolescent years. Symptoms of thyroid dysfunction may thus become more evident during this time. Thyroid dysfunction may have implications for multiple systems; cardiovascular, immune, and central nervous system effects are frequently seen. Undetected hypothyroidism may contribute to the decline in mental function over time frequently seen in individuals with Down syndrome, as well as to depression. Thyroid hormone levels should thus be monitored at least annually in affected individuals.

Sensory/Other
Other congenital malformations commonly associated with Down syndrome include:

• sensorineural hearing loss;
• ENT / Audiologic disorders such as hearing loss (either sensorineural, conductive, or mixed);
• midfacial hypoplasia; frequent purulent nasopharyngitis/sinusitis;
• tracheomalacia; tracheal stenosis; and
• frequent croup and obstruction of airways from tonsillar and adenoidal tissue

Sleep apnea is a concern for persons with Down syndrome. Symptoms of sleep apnea include snoring, sleeping in unusual positions, and restless sleep. Being overweight may exacerbate symptoms of sleep apnea due to increased fatty deposits within the pharynx. Midfacial hypoplasia typically seen in individuals with Down syndrome also contributes to pharyngeal obstruction. If untreated, sleep apnea can lead to right sided heart failure and pulmonary hypertension - and may also cause behavior and learning problems. A sleep study should be used to confirm sleep apnea when suspected. Treatment includes radio ablative tongue surgery and C-pap.

Pueschel, S.M., and Sustrova, M. (1997). Selected medical conditions. In S.M. Pueschel & M. Sustrova (Eds.), Adolescents with Down syndrome: Toward a more fulfilling life (pp. 47-55). Baltimore, MD: Brookes Publishing

Protective Genes on The 21st Chromosome
Trisomy 21 is protective in two ways; first, a gene present related to homocystine protects against atherosclerotic heart disease. Therefore, it is rare for a person with Down syndrome to have a heart attack or stroke; second, the 21st chromosome houses a tumor suppression gene. Except for testicular cancer, people with Down syndrome do not develop solid tumors.