18 May Down Syndrome – Awareness
Down syndrome is a genetic disorder that is caused by improper cell division and results in a partial or complete copy of chromosome 21. The presence of this extra chromosome causes the physical features and developmental changes associated with Down syndrome.
The human body consists of 23 pairs of chromosomes, 22 pairs that are numbered and a pair of sex chromosomes. One half of the set comes from the mother and the other half from the father. As mentioned, a partial or full copy of chromosome 21 results in Down syndrome and there are three genetic variations, namely:
- Trisomy 21 – in 95 percent of cases, affected individuals have a complete extra copy of chromosome 21 making it three present instead of two. This occurs as a result of abnormal development of either the sperm cell from the male or egg cell from the female.
- Translocation Down syndrome – when a portion of chromosome 21 becomes attached to another chromosome then this condition occurs.
- Mosaic Down syndrome – this is an uncommon form of the condition where the individual has a small number of cells with an additional copy of chromosome 21. This is due to abnormal cell division occurring after the formation of an embryo.
Signs and Symptoms
The signs and symptoms of Down syndrome vary amongst individuals affected by the genetic disorder and they can range from mild to severe. Some of the more common features of these individuals include:
- A small head and short neck.
- Flattened face with upward slanting eyes and unusually shaped or small ears.
- A protruding tongue.
- Poor generalized muscle tone.
- Short and broad hands with a single palmar crease and relatively short fingers.
- Short stature.
Most people with Down syndrome have mild to moderate cognitive impairment. Their language skills are delayed and their short and long-term memory may both be affected.
There are parents who have an increased risk of having a baby with Down syndrome and factors that elevate this risk include:
- Carrying the genetic translocation for the disorder – both the father and mother can pass genetic translocation for Down syndrome down to their child.
- Advancing maternal age – the chances of a woman having a child with Down syndrome increases with age because there is a higher risk of abnormal cell division occurring when the eggs are older. The risk of having a child with Down syndrome is elevated after the age of 35.
- Having a child with Down syndrome – parents who already have a child diagnosed with Down syndrome have an elevated chance of having another child with this genetic disorder.
Pacific Reproductive Center
Pacific Reproductive Center is a specialized medical facility that performs preimplantation genetic testing through specific genetic analysis techniques such as polymerase chain reaction (PCR) and fluorescent in situ hybridization (FISH) tests.
These techniques are performed in order to identify any chromosomal abnormalities or defects within fertilized embryos, especially in those women and couples who present with the factors that can increase the risk of their child developing a genetic disorder such as Down syndrome. These embryos are then discarded and those without any issues are chosen for in vitro fertilization.