Medical researchers have reported the largest ever series of 116 cases of Madras Motor Neuron Disease (MMND), a unique degenerative neurological disorder predominantly affecting young individuals of South Indian origin1.
The series, compiled over 36 years and reported by researchers at the National Institute of Mental Health and Neurosciences, Bangalore, reinforces the stereotype clinical symptoms earlier reported for the disease such as progressive hearing impairment leading to deafness, facial muscle weakness, difficulty in speaking with low volume speech and loss of hearing.
Described first in 1970, MMND is a rare disease with most reports from southern India and only a few sporadic cases reported from outside India. The series reports the mean age of onset of the disease as 15.8±7.9 years and a survival range between 12 months to 30 years. Majority of the patients studied had a slowly evolving disease with long stable periods.
"Many families have multiple members affected with the same illness suggesting it could be a possible genetic disorder," says Ananthanarayan Nalini, the lead researcher. Environmental factors might also play a role in view of its limited geographical distribution, she adds.
Genetic studies are presently being conducted to detect the gene abnormality and pin down the cause of the disease.