August 13, 2019 | By Dr. John O'Brien
Genetic testing is
becoming more accessible and commonplace, with new genetic links to diseases
regularly being identified. However, the many constraints on the use of
predictive genetic tests in insurance means that the easy availability of
direct consumer testing is an issue that the industry must consider
very carefully.
Genetic science is
actually relatively young. Gregor Mendel (1865) is credited with
recognizing the transmission of dominant and recessive genes, and towards the
end of the 19th century chromosomes were identified in dividing cells
under light microscopy.
Messrs Watson and Crick
revealed the structure of DNA in 1953 and our understanding of human genetics
has progressed rapidly over the last 30 or 40 years. Genetic links to
diseases have been recognised for a long time. A good example is haemophilia,
which is carried by an X-linked recessive gene and therefore occurs almost
exclusively in men.
Genetic tests can be
used to give a risk assessment of the development of a disease in the future
(predictive tests) or can help confirm an existing condition (diagnostic
tests).
Genotyping looks at
segments of DNA known as single nucleotide polymorphisms (SNPs). These are
variations in sites of DNA identified as being associated with diseases. They are
not necessarily causative and are not reliably predictive of the development of
a condition.
With the development of
next-generation technology, gene sequencing has become quick and relatively
affordable. This technique allows the whole genome to be assessed - rather than
looking at specific sites associated with previously described diseases.
When assessing the risk
of manifestation of a genetic trait, the mode of inheritance is clearly
important. For a recessive condition to manifest, the individual must inherit
the causative gene from both mother and father. If the condition is dominant,
then one gene is sufficient. If the condition is a recessive condition, then
the person carrying the gene is very unlikely to manifest the condition.
Understanding these
concepts is important in interpreting information that may be provided
regarding insurance applicants. The insurance industry is particularly
concerned about predictive tests. Very few tests are 100% predictive since even
if they do predict the condition, they don’t necessarily predict the degree of
penetrance (the proportion of individuals carrying a particular genetic
abnormality that will express the clinical symptoms associated with it) or
expressivity (which measures the extent to which a given genetic trait
is expressed).
A significant
development for Life and Health insurers is that over-the-counter genetic tests
are becoming increasingly available, and the results go direct to the customer
as opposed to being recorded in any medical database. This not only creates the
potential for anti-selection, but it also raises a number of concerns regarding
the appropriate use of these tests.
From an insurance
perspective, the use of genetic information is often limited by legislation or
by agreement. In many if not most countries, the use of predictive genetic
information to adversely rate an insurance applicant is not permitted. In the
UK, there is a moratorium on the use of predictive genetic tests, apart from
Huntington’s Disease (for insured amounts over GBP500,000).
It’s important to
understand the different types of testing and their implications for
underwriters. There are single gene mutations associated with serious
illnesses, such as cystic fibrosis, but many conditions, such as ischaemic
heart disease, are polygenic in origin. This type of condition in particular is
often modified either positively or negatively by behavioural factors such as
smoking, diet and exercise. Equally, it is advisable not to ignore a positive
family history of disease because there is a negative genetic test.
Over a century ago Queen
Victoria was accused of waging biological warfare on the royal houses of Europe
after she passed on the haemophilia gene to two of her five daughters, Princess
Alice and Princess Beatrice. The mutation was subsequently passed on to the
royal families of Spain, Germany and Russia.
So genetics has long
been a contentious topic - and no doubt will continue to be so.
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