Eight things you should know about genetic disorders before jeans for genes day
Jeans for genes is an initiative that raises funds to help UK children and families affected by genetic disorders. Lisa Salmon finds out more
YOU may have heard of a few genetic disorders, like cystic fibrosis, Down's syndrome and haemophilia – but it's unlikely you'll know of them all, as around 6,000 of these often devastating conditions affect more than half a million people in the UK.
It's estimated that one in 25 children has a genetic condition of some sort, varying in severity. To support children and families affected by these conditions, Genetic Disorders UK (geneticdisordersuk.org) runs the annual fundraising campaign Jeans for Genes Day (jeansforgenesday.org), which falls on September 21 this year. The day simply asks people to wear jeans or denim to school, work or at home, and make a donation to the charity at the same time.
Here, Anna Whaite, a Genetic Disorders UK genetic counsellor, outlines eight things everybody should know about genetic disorders....
1. Genes and genetic disorders vary wildly
Some genetic disorders are apparent at birth, while others are diagnosed at different stages throughout childhood, and even into adulthood sometimes. We all carry thousands of genes (made of DNA and carried on chromosomes inherited from our parents), which are instructions for how our bodies grow and function.
"The exact code of our genes varies from person to person, which is why we're all different," she says. "If someone has an alteration which disrupts a gene, that can cause a genetic disorder."
2. We can't change our genes
Once a genetic disorder has been diagnosed, there may be treatments and interventions available to help manage the symptoms, but sometimes there's no medication that can help.
"Living with the disorder can add a huge strain on an individual's and a family's day-to-day life," says Whaite. "
3. Chromosome changes can cause some genetic disorders
While many genetic disorders are caused by changes in single genes, others are due to changes to chromosomes, the structures that carry genes. For example, Down's syndrome is caused by having an extra copy of chromosome 21, instead of the usual two.
Other chromosome changes can mean parts of a chromosome are deleted or duplicated, or sometimes swapped around, affecting development.
4. Gender matters
Some genetic disorders affect males and females differently, particularly if they're X-linked (caused by a change in a gene found on the X chromosome). This is because females have two 'X' chromosomes and males have one 'X' and one 'Y' chromosome.
If there's a genetic change in a gene on the 'X' chromosome, for example with Duchenne muscular dystrophy – an X-linked condition – a male would show symptoms of this. "A female with the same gene change may have only mild symptoms or no problems at all," explains Whaite, "as she has another X which would be healthy and helps to compensate for the other X."
5. Some inherited disorders are still a mystery
While many genetic tests are available to make or confirm a diagnosis, there are some inherited disorders that can't yet be detected by a gene test.
Whaite says: "Huge scientific efforts, like The Human Genome Project and related schemes, have completed a map of the entire human genome (all of the genetic material on a living thing's chromosomes), but it will take many more years to find out what each gene does and how they interact with one another."
6. Genetic disorders aren't always inherited
Some genetic disorders run in families and have been around for generations, like Huntington's disease. But others happen when two healthy carriers have a child with a genetic disorder – cystic fibrosis, for example.
7. Chance has no memory
When someone with a genetic disorder has children, the chance the disorder will be passed on is the same for each pregnancy. If a recurrence risk of a genetic disorder is 50 per cent, this risk is the same each time a baby is conceived – it doesn't mean that if the first child is affected, the next will automatically be OK.
8. Help is available
Talk to your GP if you're worried about a genetic disorder in your family. They can refer patients to NHS genetics clinics, which provide testing and genetic counselling.
:: Support is also available for children and families through disease-specific support groups and charities such as Genetic Disorders UK, which runs a free helpline on 0800 987 8987. For more see geneticdisordersuk.org and belfasttrust.hscni.net/services/2687.htm