The role genomics plays in relationships – 18 August 2021

According to National Today, the website dedicated to highlighting every day celebrations and holidays, August 18th is ‘National Couple’s Day’ – a day to celebrate the important relationships in life. Whilst not an official holiday or observance in any country, the clinical team at Yourgene Health wanted to use this opportunity to reflect upon the pivotal role that genomics plays in relationships across the world.

Earlier this year a study, published in Nature Human Behaviour, found evidence that a person’s health and lifestyle can be influenced by the genetic make up of their romantic partners (1). Using data from over 80,000 couples, the group found a number of at least partially causal relationships whereby one person’s genotype was having an observable impact on another person’s phenotype. Examples include mood swings and self-reported red meat intake. The research group believe this finding could have important implications for public health, but do recognise that this work is very much in its infancy at this time. For example, data was obtained only from heterosexual couples, and many of the characteristics considered were self-reported (such as nutritional behaviours). The group note the specific challenges faced in distinguishing true indirect genetic effect from assortative mating. For example, height is well known to correlate in couples due to assortative mating rather than indirect genetic causes.

The idea that people may tend to be more genetically similar to their spouses is not a new one, and neither is the idea of friends being more genetically alike than strangers. In 2018 the concept of a ‘social genome’ was reported, whereby genetic similarity across the genome was observed between friends relative to random pairs of individuals (2). The reasoning behind this has been attributed to both so called ‘social homophily’, the idea that people form bonds based on shared characteristics, many of which are genetic in origin. However, another explanation may be that that people are drawn to people who share a similar social environment, which may itself be underpinned by genetics (3).

The above works consider whether your genetic make-up may indirectly impact upon your partner, but there are examples of more direct and obvious influence to be seen. Dor Yeshorim,‎ also known as the Committee for Prevention of Jewish Genetic Diseases, is an organisation offering genetic screening to members of the Jewish community across the globe. The group offer testing to individuals for recessive genetic diseases prevalent in both the Ashkenazi and Sephardi Jewish populations. Couples are then offered what is termed a ‘compatibility check’ at the start of their relationship, whereby carrier status for each disorder is cross-checked. In this way, any couple whereby both individuals are carriers of the same condition can be informed of the result, and counselling can be offered as is appropriate. The Dor Yeshorim program is unique in many respects, not least because it is entirely confidential – even to the individual themselves. An individual cannot obtain information about their own carrier status; this remains strictly confidential throughput the process. Couples are treated as a single entity, with their risks only communicated relative to one another.

Genomics may play an important role in how individuals choose a partner or friendship, but so too can shared genetic history bring communities together. There are a myriad of patient-led and non-profit support groups for individuals with a personal experience of genetic disease. Some groups focus specifically on a given disorder, for example the Cystic Fibrosis Trust, whilst others look to support a broader range of individuals. These groups are important sources of both information and support for individuals, their families and those who care for them. Often these groups lead to the formation of lifelong friendships, many of which reach internationally.

From Yourgene Health we wish you a very happy ‘National Couple’s Day’; we look forward to continuing to support innovation within genomics to support healthy and happy relationships across the world.