Although there are strict limits on insurers using genetic testing, the health of an applicant's immediate family can provide valuable clues to their future well-being, writes Sandra Wood
Obtaining details of an individual's family history is a long-established method used to recognise possible future health problems that might otherwise be unsuspected.
Many disorders have been recognised as occurring more in some families than others.
In the UK, insurers are only allowed to ask about first-degree relatives (parents, siblings, children) but even this information provides clues to the genetic and environmental influences affecting an individual's health.
Our physical make-up and characteristics, although influenced by lifestyle and environmental factors, are fundamentally determined by the genetic material obtained from our parents at the time of conception.
Gene abnormality
Some of the conditions an underwriter asks about are caused by a single gene abnormality, such as Huntington's, but it is also recognised that interactions between several different genes can make a person susceptible to developing many common disorders including cardiovascular disease and cancer, particularly if environmental and lifestyle influences favour their development
The total genetic material which makes up our cells is called a genome and comprises two strands of DNA containing 100,000 genes. The genes, which have been inherited from our parents, are arranged in pairs, as 23 pairs of chromosomes. 22 of these pairs are autosomes and the remainder are sex chromosomes.
Genes can be classed as dominant or recessive. A dominant abnormal gene will cause the relevant disorder even if its partner on the paired chromosome is normal. If one parent has one of these abnormal genes there is a 50% chance that any children will inherit the abnormal gene and go on to develop the condition.
These rare conditions are known as autosomal dominant disorders and include polyposis of the colon (familial adenomatous polyposis), HNPCC (hereditary non-polyposis colorectal cancer or Lynch syndrome), Huntington's disease, polycystic kidney disease and familial hyperlipidaemia.
However, these conditions can also appear in a family without any previous history through genetic mutation.
Familial adenomatous polyposis has an incidence of one in 8,000 and is characterised by the early development of numerous polyps in the colon and rectum. By adolescence there could be as many as 1,000 polyps in the colon. So great is the chance of developing colon cancer before the age of 45 that individuals with the condition often undergo preventative surgery to remove the colon.
HNPCC is divided into Lynch I and Lynch II syndrome. It is not associated with polyps but individuals carrying the gene have a particularly high risk of developing colon cancer. It accounts for between 1% and 6% of all colorectal cancers. Lynch II can also involve other types of cancer including ovarian, breast, pancreas, bile duct, endometrium and stomach. A person with Lynch II runs seven times more risk of getting colorectal cancer.
Huntington's disease is a rare degenerative disorder of the central nervous system. A child who has inherited the gene will almost always show symptoms at some stage. The usual clinical signs are twitching and dementia starting in mid-life, mainly between the ages of 30 and 50, but there are forms which can start as early when the sufferer is 20, or not reveal themselves until they are 80. Following the onset of symptoms the disease follows a slow deteriorating course over 10 to 20 years ending in death.
Polycystic kidney disease (PKD) is characterised by multiple cysts in both kidneys which gradually increase in size and number until they replace all functioning kidney tissue. The most common form has a prevalence of about one in 1,000. There can also be associated cardiovascular abnormalities. Although relatively rare, it is one of the most common inherited diseases and has a strong hereditary tendency. Children of affected individuals are offered screening, meaning almost 70% of sufferers to be identified by the time they are 20. The disease is always progressive and renal dialysis or a transplant may be needed.
Familial hyperlipidaemia is caused by an abnormal gene and is one of many types of lipid disorder. The cholesterol level is very high and produces yellow deposits on the shin and in the tendons. In people with premature coronary heart disease, familial hyperlipidaemia accounts for 5% of cases. If one parent is affected cholesterol levels can be 9 mmol/l or higher and drug treatment is necessary to slow down the development of fatty deposits in the vessels. However, if both parents carried the abnormal gene, lipids deposit rapidly on arterial walls and death from heart disease is possible as early as late childhood.
Underwriters are also interested in strong family histories or early family histories of other diseases which are known to show hereditary tendencies. These include heart disease, diabetes and some cancers, but also multiple sclerosis, motor neurone disease, Parkinson's and Alzheimer's.
Studies have shown that individuals with a family history of immediate family developing coronary heart disease before the age of 55 generally have between two and six times the risk of developing heart disease of those without a family history. Similarly, a genetic disposition is well recognised in type I and type II diabetes with up to a 40% chance of developing the disease if an individual has a family history, depending on the type and the relationship to the family member who has the disease. For example, if both parents have type I diabetes there is a 20% chance their child will develop the disease.
About 5-10% of cancers are thought to be caused by inherited abnormal genes. Multiple cancers or family histories of cancers of the same type are indications that there may be some inherited disposition, particularly breast and ovarian cancers, and colorectal cancer.
First-degree relatives of people who develop colon cancer are themselves at a two to three-fold increased risk of colorectal cancer. When the family history includes two or more relatives with colon or other cancers, the possibility of an inherited syndrome is increased. Any family history of these cancers at a young age also raises the concern that there may be an inherited link.
Multiple sclerosis has an important genetic link involving multiple genes, with the lifetime risk of those with a first degree relative developing the condition ranging from 2% to 6% (excluding twins) depending on the relationship.
There are familial forms of Alzheimer's, Parkinson's and motor neurone disease which form a small percentage of cases of these conditions and early onset of any of theses conditions in a first-degree relative is something underwriters need to be aware of.
About eight in every 100,000 people in the UK have Huntington's disease - approximately 4,800 people.
The risk of someone in the general population developing MS is 1 in 1000 or 0.1%. The risk for individuals with one parent with MS developing the condition is 2%
Sandra Wood is a life and disability underwriter at Scottish Equitable Protect
Underwriting implications
When assessing family history an underwriter has to look not only at the hereditary risk, but also at the applicant having early signs of a condition or other risk factors which may encourage the condition to develop.
Applicants with a family history of heart disease or diabetes (two family members under 60) may find themselves being offered substandard rates for life and critical illness protection, even in the absence of any other risk factors. This is particularly relevant to men, as pre-menopausal females are partly protected from early heart disease by hormones. In the presence of other risk factors such as smoking, obesity, hypertension and raised cholesterol, any family history of early heart disease will be used as part of the risk assessment and may be the deciding factor for any extra mortality or morbidity rating. A combination of heart disease and diabetes in family members will be classed as a substandard risk as diabetes can accelerate the development of heart disease.
When assessing a family history of cancer, the type of cancer, the number of family members affected and their ages at diagnosis need to be taken into consideration. For some types of cancer this would attract an extra mortality rating. Some non-cancerous breast and colon conditions are known to present a higher risk of cancer. Therefore, if the applicant has a history of one of these non-cancerous conditions, plus a family history of a related cancer there may well be adverse terms.
Most inherited diseases are evident soon after birth and those at a high risk of developing a hereditary disorder which does not show until later in life are usually screened. Genetic testing is also available for some hereditary disorders. However, an insurance company will not ask an applicant to have a genetic test as part of the underwriting process.
The Association of British Insurers (ABI) has a strict code of practice surrounding genetic testing to which UK insurance companies must adhere.
Any proposals with genetic implications are dealt with by the life office's nominated genetic underwriter to ensure guidelines are strictly followed.
