Tufts OpenCourseware
Authors: John Morgan, Bonnie F. Zimble

Down Syndrome:

Physical Characteristics and Health Manifestations

Special Care in Dentistry
John Morgan, DDS
Tufts University School of Dental Medicine, 2008

Study Questions

  1. Describe the physical characteristics of persons with Down syndrome.

  2. List some of the specific physical health manifestations of this syndrome.

  3. Briefly describe each of the seven systemic health manifestations of Down syndrome.

Physical Characteristics of Down syndrome 

Patients with Down syndrome present with a characteristic physical appearance that includes the following features: 

  • Flattened facial profile, with low nasal bridge and small nose

  • Upward slant to the eyes

  • Small mouth

  • Abnormal ear shape

  • Relatively short stature with a stocky build, short neck and decreased growth potential

    - Men’s average height is 5 feet

    - Women’s average height is 4 ½ feet

Health Manifestations of Down syndrome  

Some common distinctive physical health manifestations among patients with Down syndrome include: 

  • Hypermobility, or laxity, of body joints

  • Nasal air passage that is narrow and partially obstructed due to septal deviation and thick mucosa

  • Cardiac defects found in 50% of patients; mitral valve prolapse often goes undiagnosed

  • Defective neutrophils, impaired cell mediated immunity, disturbed serum immunoglobulin

  • Prone to dermal, mucosal, gastrointestinal, and upper respiratory tract infections

  • Risk of leukemia is 10-15 times more likely than in the general pediatric population

  • Motor function is delayed, with restricted function; this improves with age

  • Neurologic considerations:

-         The overall rate of dementia approaches 30%
-         After age 35, many patients undergo neurological change analogous to Alzheimer’s disease
-         Range of intellectual impairment ranges from near-normal intelligence to severe intellectual disability

 Systemic health manifestations include: 

Heart disease*

  • “Approximately half of children with Down syndrome have congenital heart disease and associated early onset of pulmonary hypertension, or high blood pressure in the lungs.”

  • Surgery has been effective “if the defects have been identified before the onset of pulmonary hypertension.”

Seizure disorders*

  • They “affect between 5% and 13% if individuals with Down syndrome, a 10-fold greater incidence than in the general population.”

  • “Seizures can be treated with anti-epileptic drugs.”

Hearing problems*

  • Studies have shown that “66% to 89% of children have a hearing loss greater than 15-20 decibels in one ear.”

  • Many hearing problems are correctable, but assessment should be undertaken early

Vision problems*

  • “Cataracts occur in approximately 3% of children with Down syndrome…but can be surgically removed”

  • Many persons with Down syndrome are myopic, and may have astigmatisms and/or strabismus

Gastrointestinal problems

  • Approximately 4% of infants with Down syndrome are born with a blockage of the small intestine (duodenal atresia)…

  • Which must be corrected surgically

Thyroid Dysfunction

  • Ten percent of individuals with Down syndrome have hypothyroidism…

  • And the incidence increases with age

Musculoskeletal problems

  • Low muscle tone puts patients with Down syndrome at risk for orthopedic problems, as well as neck injuries

  • This a consideration for participation in sports

* Information was obtained from the National Institute of Child Health and Human Development (NICHD), “Facts about Down Syndrome” 

Click here to access the NICHD site on Down Syndrome