1. Genetics Department, National Institute of Rehabilitation (INR), Mexico City, México.
2. Clinical Laboratory Department, INR, Mexico City, México.
3. National School of Biological Science, IPN, Mexico City, México.
4. Neurochemical Department, INNN, Mexico City, México.
5. Rehabilitation Board, Sistema Nacional, DIF, Mexico City, México.
6. Gastroenterology Department, INNSZ, Mexico City, México.