Genetic disorders are something you may want to look into when you’re considering starting a family. These are caused by DNA abnormalities and can be inherited from one or both parents, or even grandparents. In this article, we discuss the risks and how to assess your own if you want to know more about them.

What is a genetic disorder?

A genetic disorder results from abnormalities in your DNA. They can be sporadic or be inherited from one or both parents. Some are even inherited from grandparents. There are many genetic disorders, ranging from relatively mild conditions to life-threatening diseases. We are all thought to be carriers of multiple genetic conditions. Completely healthy carriers may be unaware of their chances of passing a condition on, which increases if their partner is also a carrier.

How likely is my baby to have a genetic disorder?

The risks of having a child with a genetic disorder depend on several factors, including the type of disorder, the way it is inherited, and the genetic makeup of you and your partner. Some genetic disorders are more common in certain ethnic groups or as we age, while others occur more equally across all populations.

If you are concerned about your risk of having a child with a genetic disorder, there are several steps you can take to assess your risk, depending on your access to support and testing in your country. In the United Kingdom, the National Health Service will offer you a screening test for Down's syndrome, Edwards' syndrome, and Patau's syndrome between 10 and 14 weeks when you are pregnant, but the cost of preconception research will fall on you and your partner. Wherever you are, you may like to contact a genetic counsellor, who can review your family history, discuss your options for genetic testing, and provide personalised recommendations for your situation.

Before becoming pregnant, you might also consider genetic testing, which can help identify whether you are a carrier for certain genetic disorders.

What if we are both carriers for a genetic condition?

If both partners are carriers of the same genetic condition, you may be advised to have more genetic counselling to better understand the test results and the available reproductive options. These options may include conceiving naturally and having the developing baby’s health monitored through prenatal testing. You may choose to invest in in vitro fertilisation (IVF), which involves the fertilisation of an egg with sperm outside the body and then implanting the embryo into the uterus. Your IVF embryos can be pre-screened for genetic disorders before implantation if you’d like to rule out any chance of passing on a disorder you know you or your partner is carrying. You could also use donor sperm or eggs to conceive to reduce the chances of a condition being inherited.

What are some common genetic disorders?

There are many types of genetic disorders, some of which are more common than others.

You may be offered testing for autosomal recessive conditions such as spinal muscular atrophy (SMA) and cystic fibrosis (CF) and X-linked conditions such as Fragile X syndrome (FXS). Down syndrome is caused by an extra copy of chromosome 21 and is the most common chromosomal disorder. It becomes more likely with increased maternal age. In addition, a simple blood count can identify couples at risk of thalassaemia and related blood disorders and should be performed on all women considering a pregnancy.

Some conditions are more common in particular ethnicities. For example, sickle cell anaemi, a genetic disorder that affects the production of haemoglobin, causing red blood cells to become misshapen and break down more easily, is more common in people of African, Central American, or South American descent.

What is my risk of passing on a genetic disorder to my baby?

For Unii’s Preconception Journey, we look at understanding your risk of passing on a genetic disorder.