A few weeks ago I was contacted by a journalist who is writing a story about relationships between first cousins. She was curious to get a genetic counselor’s view on the issue. When two people have children together who are related, this is called consanguinity. This word comes from the Latin meaning from the same blood. In the Australian culture which heralds from the British Isles, marriage between first cousins is not common, is not encouraged and has a certain stigma surrounding it. However in other cultures, first cousin relationships are not only okay, but they are also actively encouraged. Having children with a relative like a cousin can even have advantages. “Keeping it in the family” so to speak. Families are already aware of what “they are getting into”. They understand each other’s background and financial backgrounds.
However, most people are cognizant of the fact that there can be a higher chance of having a child with an illness when one has children with a relative. This is due to what is known as recessive inheritance. Some conditions, such as Down syndrome, are linked to the mother’s age. The older the mother is at conception, the higher her chance of having a child with a chromosome problem. Dominant conditions can spontaneously occur, due to a fault or mutation in a gene in the egg or the sperm. The chance of this happening actually increases with the age of the father. However, when two people are related, they have a higher chance of both being carriers of the same recessive condition. All of our genes come in pairs; one from each parent. With recessive genetic conditions, an affected person has two copies of the same gene that is not working properly. Their parents who have one working and one non-working copy of the gene are known as carriers. Our relatives are more likely to be carriers of the same genetic conditions and this is why the rate of genetic conditions is higher in people who are born to first cousins.
What most people don’t realize though is that this risk still isn’t really high. The chance of any two unrelated people having a child with a medical problem is about 3%. When two people who are cousins have a child, their chance of having a child with a medical condition is doubled to 6%. So more than 90% of the time there are no problems. This is explained in more details in the fact sheet written by The Centre for Genetics Education, which I have shared the link below. Genetic counsellors are equipped with the knowledge and skills to help people who are seeking information regarding first cousin marriages. We provide this medical information in a non-judgmental way free from stigma. However, consanguinity is not to be confused with incest, which is sexual relations between close relatives such as siblings or parents and children. This is illegal. Consanguinity isn’t something that a lot of people this a lot about. But people in consanguineous relationships often think about it a lot. There can be guilt and shame associated with the stigma. I hope knowing a bit more about this topic can help diminish this.
Yesterday I went to see a movie called “Three Identical Strangers”. It’s the story of three identical male triplets separated at birth and reunited at the age of 19. As a genetic counsellor I often ponder the question of nature versus nurture and this movie investigates this theme superbly. Identical twins and triplets are born with the same genetic make-up. However when these type of siblings are reared apart, there is an argument that this informs or gives an indication to which traits or attributes have a strong genetic or hereditary component and which ones are more due to one’s environment.
Research tells us that the most rigorous experiments or studies are ones called “randomized control trials” where a group of participants are randomly assigned to being an active participant or being a control. In medicine we see this type of trial where a group of people with the same condition are randomly divided into receiving either a medication or treatment under investigation or they are given a placebo and are what are known as controls. However with adoption studies, because we have modern day ethic committees who oversee all research conducted, a researcher cannot randomly assign newborns to being either adopted or to stay with their birth parents so observational studies are performed. This is where people “assign” themselves and researchers observe differences.
In psychology, these types of studies were conducted to measure personality or behavioural traits such as extroversion and psychological disorders such as depression. I am often asked if conditions such as autism or depression are “genetic”. When people say “genetic” in this context, they mean is there a strong inherited link. Science is not at the stage where there is a simple genetic test for traits or conditions like depression or autism. In reality, like most things, there is a combination between genes and environment; we may be born with a predisposition however how we are brought up or what we are exposed to can greatly influence the development of these attributes.
People are amazed with how identical twins (either separated at birth or not) are similar. I feel that these similarities are encouraged and reinforced. Twins separated and reunited like seeing what they have in common. It reminds me of when people start a new romantic relationship, couples dwell in what they have in common. It is not usually until later do couples consider how they are different.
Isn’t it lovely that we as humans have influence on what we experience or how we are as people? Our personalities and our traits and what makes us, us are not set in stone. It can change. We can change. If we have three copies of chromosome 21 we will have Down syndrome or if we have two serious mutations in our CFTR gene we will have cystic fibrosis. However if both of our parents have schizophrenia, it does not mean that we will also have this illness. If many of our relatives are outgoing, it does not mean that our children will be too. Three Identical Strangers is a fantastic documentary combining the things that I love; genetics, psychology, the theme of nature versus nurture and ethics. If this sounds like your cup of tea, check it out!
What is Genetic Counselling?
As a genetic counsellor, “what is genetic counselling?” is the most common question I am asked. Most people are not aware of ever having met a genetic counsellor and do not know what genetic counselling is or what genetic counsellors do. Genetic counselling is a relatively new profession and there is quite a bit of controversy surrounding our professional name and whether it is the best description of what our role entails.
Genetic counselling is aimed at providing information and support to people who have or are at risk of genetic disorders. A genetic counsellor is a postgraduately trained health care professional who can identify your risk factors and provides clear information about the chances of being affected by a specific genetic condition. Usually when you have a health related question or concern you go and see a General Practitioner. If this issue is genetics related, you may be referred to see a genetic counsellor.
Genetic counsellors are health care professionals who integrate their knowledge on medical genetics, basic science and counselling theory with their skills in genetic risk assessment and communication to educate their clients on a diverse set of genomic or genetic indications. They help people to understand their genetic contributions to disease. These professionals are employed in diverse settings such as public hospitals, community health centres, IVF clinics, university research facilities and private medical centres. Genetic counsellor usually have an undergraduate degree in science, nursing, social work, teaching or psychology followed by a two years masters course in genetic counselling. Once qualified and practicing in the field, genetic counsellors usually undergo an accreditation process to become certified.
Genetic counsellors investigate the genetic history of your family, arrange for appropriate genetic testing, interpret the details about your disorder, evaluate the inheritance patterns and review the options available to treat your medical condition. They will also liaise with your general practitioner and other medical specialists in regards to your results.
Some common examples of when you may meet with a genetic counsellor include:
• You have undergone routine pregnancy screening tests and have received a high risk result
• You have a strong family history of a particular condition and would like information about your risks and about genetic testing
• You have just had a diagnosis of breast or ovarian cancer and your medical oncologist would like to know whether you have an inherited reason for your history of cancer
• You have a child with a recessive condition like cystic fibrosis and would like to discuss carrier testing and options for following pregnancies
It is a rewarding and fulfilling professional and I love doing my job. There is an international shortage of genetic counsellors so it might just be a great new vocation for you too.
Consultant Genetic Counsellor
Hello and Happy New Year! I am lucky enough to be writing this first blog post of the year from sunny Byron Bay in Northern New South Wales, Australia. I’m away on vacation with my partner for some summer fun in the sun and some much-needed relaxation time after a busy and happy 2017. As I sit here contemplating 2017 and envisioning 2018, like most of you, I think about the New Years resolutions that I have made.
Continue reading “New Year Resolutions”