Down’s Syndrome

Down syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or a portion of the third copy of chromosome 21. Physical growth delays, distinctive facial features, and mild to moderate intellectual disability are typical. A young adult with Down syndrome has an average IQ of 50, which is equivalent to the mental age of an 8- or 9-year-old child, but this varies greatly.

Causes:

The presence of an extra copy of chromosome 21 is caused by a random error in cell division.

Signs and symptoms:

Physical and intellectual disabilities are almost always present in people with Down syndrome. Their mental abilities as adults are typically comparable to those of an 8- or 9-year-old. They also tend to have a poor function and reach developmental milestones at a later age. They are more likely to develop a variety of other health issues, such as congenital heart defects, epilepsy, leukemia, thyroid diseases, and mental disorders.

Diagnosis:

Before birth

When screening tests indicate a high likelihood of Down syndrome, a more invasive diagnostic test (amniocentesis or chorionic villus sampling) is required to confirm the diagnosis. If Down syndrome occurs in one out of every 500 pregnancies and the test used has a 5% false-positive rate, this means that only one of the 26 women who test positive on screening will have Down syndrome confirmed. If the screening test has a 2% false-positive rate, this means that one in every eleven fetuses who test positive on screening has DS. Although amniocentesis and chorionic villus sampling are more reliable tests, they increase the risk of miscarriage by 0.5 to 1%. Because the procedure carries a higher risk the earlier it is performed, amniocentesis is not recommended before 15 weeks gestational age, and chorionic villus sampling is not recommended before 10 weeks gestational age.

Abortion rates

In Europe, approximately 92 percent of pregnancies with a Down syndrome diagnosis are terminated. Termination rates in the United States are around 67 percent, but this rate varies greatly depending on the population studied. When asked if they would have a termination if their fetus tested positive, 23–33 percent of non-pregnant people said yes, 46–86 percent of high-risk pregnant women said yes, and 89–97 percent of women who screened positive said yes.

After birth

Based on the child's physical appearance at birth, the diagnosis is often suspected. An analysis of the child's chromosomes is required to confirm the diagnosis and to determine the presence of a translocation, which may help determine the risk of the child's parents having additional children with Down syndrome. When a possible diagnosis is suspected, parents generally want to know and do not want to be pitied. The National Down Syndrome Society has created information about the benefits of having Down Syndrome.

Management:

Early childhood intervention, screening for common problems, medical treatment when indicated, a good family environment, and work-related training can all help children with Down syndrome develop better. Education and proper care can help to improve one's quality of life. Raising a child with Down syndrome requires more effort from parents than raising a child who is not affected. Typical childhood vaccinations are advised.