For release: Wednesday, May 15, 1991
Officials at the National Institute of Neurological Disorders and Stroke (NINDS) hailed as a major research advance the mapping of a gene that causes familial amyotrophic lateral sclerosis (ALS) to chromosome 21. "This is an important first step in our attempt to better understand the basic, molecular mechanisms of this widely studied but poorly understood neurological disorder," said Dr. Roger J. Porter, deputy director of the NINDS.
Porter congratulated the international team of investigators, led by neurologist Dr. Teepu Siddique at Northwestern University Medical School in Chicago. Siddique and his colleagues reported the discovery in the May 16 issue of the New England Journal of Medicine *.
The project, supported in part by the NINDS, took 7 years and the combined efforts of 36 investigators at 21 scientific institutions in the United States, Canada, Europe and Australia. "This extraordinary scientific collaboration is in the best interests of the patients," Porter said. "More collaborative efforts of this type will be needed before we finally untangle the mysteries of this terrible disease."
Siddique and his colleagues studied 23 families with familial ALS. Using sophisticated statistical analysis, the investigators showed a gene responsible for the disease lies on chromosome 21 in a large group of the families. In a smaller group, a familial ALS gene appears to be located on a different, but undetermined, chromosome. This suggests, according to the investigators, that familial ALS may result from more than one molecular mechanism or more than one genetic defect.
As many as 20,000 Americans suffer from ALS. Most cases of the disease occur sporadically and usually result in death within 5 years. Familial ALS represents about 5 to 10 percent of the approximately 5,000 new cases of ALS in the United States each year. ALS strikes in midlife and causes degeneration of the nerve cells in the brain and spinal cord that control voluntary muscle movements. The muscles of ALS patients weaken and waste away. Eventually patients become disabled, have difficulty speaking and swallowing, and may succumb to infections, particularly pneumonia. Patients do not lose sensation or mental alertness. Currently there is no cure or preventive measure. Despite decades of research, scientists have been unable to unearth a cause for the disorder, also called Lou Gehrig's disease after the famous New York Yankee slugger whose death in 1941 was caused by the disease.
The NINDS-supported investigators also found evidence that mutations on more than one chromosome may lead to familial ALS. "Further work is needed to identify the gene or genes responsible for familial ALS, determine their faulty output, and design therapeutic interventions based on this knowledge," Porter said. "However, for the first time we have a structured, rational approach to the study of this devastating disease. Since familial ALS is clinically indistinguishable from sporadic ALS, the insights to be gained from this line of investigation may apply to both forms and possibly to other neurodegenerative disorders, as well."
The NINDS, a part of the National Institutes of Health, is the focal point within the Federal Government for research on the brain and nervous system. The NINDS supports a broad range of basic and clinical neurological investigations into ALS at leading biomedical research institutions. The goals of the program are to improve understanding of ALS, find methods of treatment, and eventually cure and prevent the disorder.
# # # #
* Siddique, T.; Figlewicz, D.A.; Pericak-Vance, M.A.; Haines, J.L.; Rouleau, G.; Jeffers, A.J.; Sapp, P.; Hung, W.Y.; Bebout, J.; McKenna-Yasek, D.; Deng, G.; Horvitz, H.R.; Gusella, J.F.; Brown, R.H.; Roses, A.D; and collaborators. Linkage of a gene causing familial amyotrophic lateral sclerosis to chromosome 21 and evidence of genetic-locus heterogeneity. The New England Journal of Medicine, 324(20), 1381-4, May 16, 1991.