15 Jun 2019
Down syndrome is a genetic disorder which occurs when an abnormal cell division results into extra or partial copy of chromosome 21. Human cell contains 23 pairs of chromosomes but this condition results into an extra chromosome, which leads to delay in development and intellectual disability in a child however, it varies with the severity. It causes mental problems as well as medical abnormalities. It is a lifelong condition which cannot be cured. Life expectancy of these patients has increased to age of 60 years but it again depends upon severity of health problems.
- Trisomy 21 – Three copies of chromosome 21 instead of two copies are formed. It occurs due to abnormal division of cell in sperm or egg.
- Mosaic Down Syndrome – This occurs after fertilization, wherein only some cells of extra copy of chromosome 21 are present.
- Translocation Down Syndrome – Some portion of chromosome 21 gets attached to another chromosome.
SIGNS AND SYMPTOMS –
- Flattened face and nose
- Shape of eyes looks like almond with upward slanting eyelids
- Small ears
- Short height with relatively short fingers, small hands and feet
- Protruding tongue
- Blood in the stool
- Heart problems
- Gastrointestinal disorders
- Low immunity
- Sleep apnea
- Spinal problems
- Other complications like seizures, hearing or vision problems
- Screening test includes first trimester combined test and integrated screening test
- Diagnostic tests includes Chorionic Villus Sampling(CVS) and Amniocentesis
There is no specific treatment available but it varies with complication, stage of life and person to person. Such supportive factors include –
- Special developmental programs
- Special schools
- Participation in social activities
- Independency in daily activities
- Advance learning of particular hobby or skills
RISK FACTORS –
- Late pregnancy
- Carriers of translocation down syndrome (inherited)
- Have one child with down syndrome
- Estimation shows that 1 out of 1000 children are born with Down syndrome worldwide.
- 5% cases occur due to Trisomy 21, 4-5% cases due to Translocation and only 1% of cases are due to Mosaic Down Syndrome.