Huntington's cases underestimated

“There are far more people with Huntington's disease in the UK than has been assumed,” The Guardian has reported. However, stigma and fear of insurance companies leads many to keep their condition a secret, it added.

The news is based on two articles about Huntington’s disease - a progressive, inherited disorder that affects the nervous system, for which there is presently no cure. The disease typically appears in middle age, affecting muscle co-ordination and leading to cognitive decline. One article discusses the negative medical and scientific attitudes towards Huntington’s, which, in the past, had supported the sterilisation of families who carry the gene. The other is a commentary that argues that the estimated prevalence of Huntington’s may be double the standard estimates of about six to seven in 100,000, but that stigmatisation and financial penalties in insurance policies may lead people to conceal the condition.

The articles are timed to coincide with the launch of an all-party parliamentary group to promote greater understanding and awareness of Huntington’s. While both are based to some extent on personal opinion, they highlight a serious issue for sufferers of the disease and their families and will perhaps lead to advances in both treatment and perceptions of this devastating illness.

Where did the story come from?

The narrative review was written by Alice Wexler, an historian from the UCLA Center for the Study of Women in Los Angeles, whose sister led the discovery of the underlying genetic abnormality that causes Huntington’s disease. The accompanying commentary is written by Sir Michael Rawlins, honorary professor at the London School of Hygiene and Tropical Medicine and chairman of the National Institute for Health and Clinical Excellence, who has helped establish the new all-party group on Huntington’s disease. Both articles were published in the peer-reviewed medical journal, The Lancet.

The articles were covered accurately in the media, with the BBC saying that this ‘devastating brain condition’ is ‘at least twice as common as previously thought’. The Guardian focused in particular on the insurance penalties faced by families who carry the gene. People who have tested positive for the Huntington’s gene are required to declare their status when applying for life insurance policies over £500,000.

What kind of research was this?

Both these articles present evidence to support their views that Huntington’s is and has been stigmatised by scientists and clinicians and that its prevalence has been underestimated. The commentary, on which most news stories are based, looks at the evidence on the numbers of people with Huntington’s in the UK and argues on the basis of this evidence that prevalence is far higher than has so far been estimated. The other article is a narrative review of both social and scientific attitudes towards Huntington’s that assesses a range of historical evidence from over the last century.

What did the articles say?

Alice Wexler’s article begins on a personal note, explaining that although the disease had killed several members of her mother’s family, it was never mentioned until her mother herself was diagnosed. This missing family history she says, may explain why she became a historian, to understand her ‘mother’s shame’ and ‘the origins of her devastating silence’.

She describes how the discovery that Huntington’s was an autosomal dominant disease (one in which the gene only needs to be passed to a child from one parent in order for it to be inherited) at the beginning of the century, coincided with emergence of the eugenics movement, which supported selective breeding as a way ‘to improve the species’. As a result, there were calls for immigration restrictions, surveillance and compulsory sterilisation of families with a history of the condition. She cites evidence to show that scientists and physicians have historically linked the disease with ‘feeblemindedness, insanity, suicide, criminality and drug addiction’. One much-admired paper by a US psychiatrist, published in 1932, linked sufferers to ancestors accused of witchcraft.

Wexler says that such stereotyping gave a rationale for doctors to endorse celibacy or even sterilisation for people at risk, and it was only with the advent of civil rights in the 1960’s and 70’s that research priorities and representations of people with Huntington’s began to change. It was only at this point that the witchcraft link was discredited.

The accompanying commentary points out that each child of a parent with Huntington’s has a 50% chance of developing the disease, so the stigma attaches to those who are at risk as well as those with symptoms. It says that local UK studies have found the prevalence of Huntington’s to be on average six to seven per 100,000 of the population, but it argues the true prevalence is unquestionably far greater.

About 6,700 people diagnosed with the disease are currently being cared for by the Huntington’s Disease Association, meaning the minimum prevalence is at least 12.4 per 100,000. It argues that since an unknown number of patients with the disease have never been referred to the association, this is ‘unquestionably an underestimate’.

The most important reason for this underestimate, says the commentary, is the stigma associated with the condition. Huntington’s disease is the only genetic condition for which the insurance industry financially penalises those at risk.

How did the researchers interpret the results?

The narrative review concludes that ‘medical histories matter’ and scientists and clinicians have created ‘historical narratives’ that have deepened the stigmatisation of people with Huntington’s and lead to harmful psychological and social legacies. The accompanying commentary concludes that this stigmatisation means its prevalence has been underestimated and families with a member who have this distressing disease often try to conceal its ‘true nature’, even from their own doctors.

Reliable estimates of prevalence are needed for two reasons, the commentary argues. Firstly, so that appropriate health services can be provided, both now and in the future, for both sufferers and their families and secondly, so that any possible future treatments can be started in those at risk, before neuropsychiatric changes have occurred and symptoms of this deadly condition develop.

Conclusion

Huntington’s disease is a distressing disorder for which at present there is no cure. Therefore any articles that can promote awareness of the disease or shed light on its prevalence and historical attitudes, are to be welcomed.

Although both these articles present personal opinions, based on an assessment of the evidence, it seems possible, as the commentary points out, that the prevalence of Huntington’s has been underestimated and that more research into this area is needed. This is an important issue, in terms of the provision of services and also of research into treatments, especially treatments for those who might be at risk.