Etm. Hille et al., Two centuries of mortality in ten large families with Huntington disease: A rising impact of gene carriership, EPIDEMIOLOG, 10(6), 1999, pp. 706-710
Citations number
34
Categorie Soggetti
Envirnomentale Medicine & Public Health","Medical Research General Topics
To estimate the impact of the Huntington gene on mortality, we studied ten
families with Huntington disease, whose records started before 1800. We inv
estigated mortality from 1800 to 1997 in 257 carriers of the Huntington gen
e and 474 potential carriers. Follow-up extended from age 20 years to the d
ate of death or end-of-study date. The observed deaths were compared with t
hose expected on the basis of the general population, adjusted for sex, age
, and calendar time. To study the influence of the family and parental tran
smission, we calculated hazard ratios adjusted for sex, probability of carr
ying the gene, and year of birth. In 25,013 person-years, 420 deaths occurr
ed, whereas 278 deaths were expected [standardized mortality ratio = 1.5; 9
5% confidence interval (CI) = 1.4-1.7]. Excess mortality was confined to ag
es 40-70 years (standardized mortality ratio = 2.2; 95% CI = 1.9-2.4). To s
tudy the evolution of mortality over time in this age group, we calculated
absolute mortality rates per calendar period. From 1800 onward, mortality r
ates in the general population continuously declined, but among the familie
s with Huntington disease this decline was absent There were only small dif
ferences in risk between families, and:the relative risk for paternal over
maternal transmission was 1.2 (95% CI = 0.9-1.5). Our main finding is that
persons who carry the Huntington gene and reach middle age have not benefit
ed from advances in medical care and overall increase in life expectancy.