Two teams of scientists have found that genetic variations on a particular chromosome appear to play a role in a fatal motor neuron condition called amyotrophic lateral sclerosis.

In one of the studies, Bryan Traynor of the US National Institutes of Health along with an international group of colleagues examined the genomes of 405 amyotrophic lateral sclerosis (ALS) patients in Finland and 497 people without this disease.

The investigators threw light on the genetic variations on chromosome 9 which are linked to increased risk for ALS.

In the second study Ammar Al-Chalabi, Kings College London, led an international team to analyze DNA samples from 599 ALS patients and 4,144 controls in the United Kingdom, and observed evidence of a relation between two genetic variations on chromosome 9 and ALS.

The findings were published online Aug. 30 in The Lancet Neurology and these add to the already existing evidence that a region of chromosome 9 is linked to increased risk of ALS across multiple populations.

As per the report, the DNA samples were collected from patients who attended an ALS specialty clinic which receives referrals from neurologists across Finland.