Chromosomal Disorders, Down Syndrome & Genetic Testing
At Genetics.ie, we offer a range of testing services that give patients the important information they need about themselves and their family's health. One area in which we have much experience is in the testing of chromosomal disorders.
In this article, we look at chromosomal disorders, down syndrome in particular and the genetic testing that’s able to determine if a person is affected by the condition.
What Are Chromosomal Disorders?
The term chromosome disorder is a general one that describes individuals who deviate from the typical 23 XX pairs for women and XY pairs for men. Those who have a chromosome disorder may only be aware of the problem once they have a child.
It's important to note that these kinds of structural chromosomal rearrangements are often associated with stillbirth, recurrent miscarriages, developmental disorders and birth defects such as Down Syndrome. As such, prospective parents need to know if they’re affected.
What is Down Syndrome?
Down syndrome is something that affects roughly 1 in 700 people and there are three main types of the disorder:
Trisomy 21 - the most common type (around 95% of cases) that occurs when a fetus has three copies of chromosome 21 in every cell, rather than the usual two.
Translocation - the second most common (around 4% of cases) in which there’s an extra partial or full amount of chromosome 21 attached to another chromosome.
Mosaicism - this is the rarest type (just 1% of cases) of Down syndrome where some cells contain 47 chromosomes.
Every healthy human cell contains 23 pairs of chromosomes and Down syndrome occurs because of changes in how chromosome 21 divides. Trisomy occurs randomly and isn’t inherited, however, for translocation and mosaicism, hereditary causes should be examined.
When prenatal screenings, blood tests and ultrasounds are conducted, it’s to check for markers that Down syndrome might be present. Other ways to diagnose the disorder include chorionic villus sampling (CVS) and amniocentesis.
Helping You Get the Information You Need
We understand how important this information is to those looking to start a family, so you can always trust our team to act with the utmost care and meet the highest clinical standards. All testing at our Blackrock clinic is carried out under the watchful eye of founder Dr Willie Reardon - someone with decades of expertise and experience - so you’re in very good hands.
To find out more about the full range of testing services we offer, visit us today at www.genetics.ie. Alternatively, call us on 01 206 4329 where a friendly member of our team is waiting to help you in any way they can.