ABSTRACT – Down syndrome is a genetic disorder which occurs when an abnormal cell division results into extra or...
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
Short height with relatively short fingers, small hands and feet
Blood in the stool
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
Participation in social activities
Independency in daily activities
Advance learning of particular hobby or skills
RISK FACTORS –
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.