Down Syndrome

Also Know As Trisomy 21

Down Syndrome

Down syndrome is a genetic disease that causes intellectual and physical impairments with varying severity. Many other health conditions are associated with the disorder including heart defects, leukemia and gastro-intestinal diseases. ^[1] The disorder is the most frequent and best studied chromosomal disease in humans. It is also being ranked as the top cause of cognitive disability. ^[2]

Epidemiology

It is estimated that around 6000 children are born with the disorder annually. Generally, both genders are affected with equal incidence. It occurs in any race however patients with African American descent are reported to have shorter life span as compared to whites. ^[2]

Causes

The classic cause is called nondisjunction. It is an occurrence whereby a pair of chromosomes did not succeed to separate during egg (or sperm) formation ultimately leading to 3 copies of chromosome 21 instead of the normal 2.  Research shows that nondisjunction seems to take place more commonly in older women thus being pregnant at an age of 35 and greater is considered a risk factor to develop the syndrome. ^[3]

Other forms of the disease are called translocation Down syndrome and mosaic Down syndrome which involves other genetic processes. ^[4]

Signs and Symptoms

Patients characteristically possess distinctive facial features. Among these are flat face, small broad nose, short and broad neck, abnormally shaped and low set ears, white spots on the colored area of the eye (Brushfield spots), protruding tongue,  dental abnormalities and upward slanting eyes. Patients usually have shortened extremities, simian palmar creases, dry skin, low muscle tone and delayed development and growth. ^{[1] [2] [3]}

Diagnosis

When there is a high index of suspicion, prenatal screening tests are important which include expanded alpha-fetoprotein (AFP) screening test and the nuchal translucency test. Supplementary ultrasound screens may be helpful. To confirm the condition, cytogenetic studies are often done. Fluorescence in situ hybridization (FISH) may also be performed.  ^{[1] [2]}

Treatment

There is currently no cure however physical therapy and speech therapy are available to help patients cope better with the condition. Timely surgical procedures may be imperative to thwart serious complications especially with regards to heart abnormalities. Enriched environments and strong social support are extremely essential.  ^{[2] [3]}

References:

1.      http://www.onhealth.com/down_syndrome/article.htm

2.      http://emedicine.medscape.com/article/943216-overview#a0101

3.      http://learn.genetics.utah.edu/content/disorders/whataregd/down/

4.      http://ghr.nlm.nih.gov/condition/down-syndrome

Efficacy of Alternative and Other Treatments According to GRADE* Ranking:

Psychomotor Patterning:

Please note, this management does NOT treat the condition itself. It is proposed only as a weak supportive symptomatic support, and even then, has insufficient evidence to back up this claim at present. 

Recommendation: No recommendation (There is insufficient evidence to support claims that psychomotor patterning is able to help treat down syndrome)

Grade of Evidence: Very low quality of evidence

* www.gradeworkinggroup.org

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