Long ring finger linked to Lou Gehrig’s disease

By Dr. Ananya Mandal, MDMay 11 2011

In some of the latest studies it has been found that finger length could be linked to various traits in people with amyotrophic lateral sclerosis, better known as ALS or Lou Gehrig’s disease. These people tend to have longer ring fingers, compared with their index fingers, than do people without the disease.

For the study the British researchers measured the length of the index and ring fingers of 110 people with and without ALS. Dividing the index-finger length by the ring-finger length gives a ratio that is linked to testosterone levels in the womb, which is related, unsurprisingly, to whether the hand belongs to a male.

More men get ALS than women, but researchers wanted to test whether high levels of testosterone, not simply being male, might be associated with the disease. After controlling for gender, researchers found the index-to-ring finger ratio was lower among the patients with ALS, they reported online last week in the Journal of Neurology, Neurosurgery and Psychiatry. However experts say it doesn’t mean people with longer ring fingers are necessarily at greater risk for the rare disease.

Previous studies have connected index- and ring-finger length to SAT performance, index-finger length to prostate cancer risk, likelihood of homosexuality and likelihood of financial success. Experts believe a longer fourth finger relative to the index finger could be partly determined by how much exposure a baby has to the male hormone testosterone before birth.

Dr Brian Dickie of the Motor Neurone Disease Association, said, “This simple, but carefully conducted study raises some interesting questions about how events occurring before birth may increase the risk of developing motor neuron disease later in life. But it's important to remember that exposure to higher testosterone in the womb does not directly cause motor neuron disease. Many people with long ring fingers will never develop motor neuron disease as we believe there are numerous genetic and environmental factors that need to coincide in order to trigger the disease.”