But that is a big assumption. Many people acquire Huntington’s before or during their reproductive years, says Jane Paulsen, director of the Huntington’s Disease Center at the University of Iowa. Although the average age of diagnosis is 39, it ranges from age two to 82, depending on mutation severity. “You’re talking about such a small subsample of the population that really would have their presymptomatic years be commensurate with their reproductive years,” Paulsen says.
And even if the disease does not fully develop until later in life, people with the gene often experience psychological changes such as depression and cognitive deficits many years before diagnosis, says David Rubinsztein, a molecular neurogeneticist at the University of Cambridge; these changes might influence their decision or ability to have children. “I’m not entirely convinced that patients who have Huntington’s disease are necessarily more fecund than those who don’t,” he says.
Starks points out that his model, published in the November 13, 2007, Medical Hypotheses, is indeed speculative. He hopes, however, his ideas linking increased p53 to reduced cancer risk and increased family size will spark further studies. Paulsen agrees that even if the model is wrong, it is certain to raise interest and is a good thing. “What does provocation do to science?” Paulsen asks. Ideally, “it makes it better. That’s what hypotheses are for.”
This article was originally published with the title Disease for Darwinism.