National Institute of Mental Health and Neuro Sciences (NIMHANS) and Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) have identified a spot in the brain where a gene is responsible for causing hot water epilepsy. This is an unusual form of reflex epilepsy where seizures are suddenly caused when taking bath in hot water over the head. The condition is known to have a genetic basis.
A team of scientists from both NIMHANS and JNCASR have been involved in the study which spanned for the last four years. The study which commenced in 2004, was funded by the Indian Council of Medical Research (ICMR), Department of Atomic Energy (DAE), and the Department of Biotechnology (DBT).
This is the first identification of a locus for an unusual neuro-behavioural clinical phenotype. Research has indicated that there is a genetic location for the disorder at the 10th chromosome which is known as 10q21.3q22.3.
The team of researchers was led by Prof P Satishchandra, professor neurology, NIMHANS along with Dilip Kumar and Girish Gadre also from the same Institute supported by Anuranjan Anand, Rinki Ratnapriya and Ramesh Reddy from JNCASR. They assessed the gene samples of 304 epilepsy patients which included 70 families reporting the condition of hot water epilepsy. In fact one family had four generations of patients with 10 affected members. Maximum number of cases of the reflex epilepsy are prevalent in south India which mainly included states of Karnataka and Tamil Nadu although there were cases being reported of the same disorder in other parts of the country. It manifested mostly in patients aged five to 35 years.
The finding will help scientists understand reflex epilepsy and science behind it. It will also provide extensive information about the seizure disorder in general. Further, it will help to carry out further analysis of the candidate genes to identify the exact gene responsible for hot water epilepsy. Hasty hot water poured on the head and body during bathing leads to a gaping expression, stiffened body muscles and impaired consciousness for those patients suffering from hot water epilepsy.
The interpretations made during the analysis have brought about the researchers to conclude that hot water epilepsy could be because of an abnormal thermo-regulatory system, which is sensitive to sudden spurt in regional temperature following hot water bath.
The study was also published in the Human Genetics, an international journal for genetics. While the Magnetic Resonance Imaging (MRI) scans failed to show the structural lesions in the brain, it was the Single Photon Emission Computerized Tomography (SPECT) scan of the brain which highlighted the hypermetabolic state in medial temporal lobe and hypothalamic areas of the brain during the seizure.
Hot water bath taken at temperatures 35 degree to 40 degrees Celsius was sufficient to trigger the seizure in patients. Globally such a type of epilepsy is reported in countries like Canada, UK, Japan and Turkey. "Familial clustering in hot water epilepsy has suggested a genetic component as the probable cause of the disorder, according to the team of researches."