June 7, 2011
Amyotrophic lateral sclerosis (abbreviated ALS) is a form of motor neuron disease caused by the degeneration of neurons in the brain. The condition is often called Lou Gehrig’s disease in North America, after the famous New York Yankees baseball player who was diagnosed with the disease in 1939. The disorder is characterized by rapidly progressive weakness, muscle atrophy and fasciculations, spasticity, dysarthria, dysphagia, and respiratory compromise. ALS is a fatal disease with most affected patients dying of respiratory compromise and pneumonia after 2 to 3 years; although occasional individuals have a more indolent course and survive for many years. The cause is usually unknown, but a new Canadian finger length study suggests that the onset of ALS may even be determined before birth!
For patients without a family history of the disease, which includes ~95% of cases, there is no known cause for ALS – though environmental causative factors have been indentified.
Interestingly, earlier this year a new Canadian finger length study suggests that the onset of ALS may partly be established even before birth!
The Canadian researchers report:
“A biomarker that has generated considerable interest is digit ratio, the ratio of the second (index) finger to the fourth (ring) finger, 2D:4D. Men have a longer fourth digit relative to the second digit than do women, and the ratio is lower in boys and men than in girls and women. 1 A reduced 2D:4D ratio is assumed to indicate reduced prenatal androgen exposure or sensitivity and high prenatal testosterone levels.”
PEOPLE WITH A LONGER RING FINGER ARE NOT ‘AT RISK’!
The researchers hasten to explain, however, that this does not mean people with long ring fingers will develop the disease — or even that they are at higher risk for it.
“We have not done a study that shows the risk of subsequently getting ALS in people with long ring fingers,” cautioned lead researcher Ammar Al-Chalabi, a professor of neurology and complex disease genetics and director of King’s MND Care and Research Center at King’s College London.
What the study does find, Al-Chalabi said, is that “people with ALS tend to have more ‘male’ hands in that the ring finger is relatively longer than the index finger – something that is a tendency in men.”
“We already know that ALS is commoner in men, but this might suggest that the reason is something to do with the balance of hormones we are exposed to in the womb, because finger length seems to be determined in part by the amount of male hormone a developing baby is exposed to,” he added.