Analysis of the vascular endothelial growth factor and angiogenin genes as risk factors for amyotrophic lateral sclerosis in the Turkish population; identification of a possible novel mutation

Abstract

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disorder, which is primarily characterized by the death of motor neurons in the cerebral cortex, spinal cord, and brainstem. Degeneration of motor neurons leads to progressive wasting and eventual paralysis of skeletal muscles. Only a small portion of all ALS cases show familial inheritance (FALS), and the remaining majority of patients are sporadic (SALS). Still, a genetic component is thought to contribute to SALS pathogenesis. Despite intensive research, the mechanisms leading to neurodegeneration in ALS have not been fully understood. Identification of genes, either underlying ALS or predisposing to ALS, has been an important part of ALS research. Among several etiologic gene candidates, thought to be associated with SALS, Vascular Endothelial Growth Factor (VEGF) and Angiogenin (ANG) aroused particular interest, because they are well-known factors for their angiogenic activities. In the framework of this thesis, we examined the link between ALS and the reported VEGF and ANG gene variations in the Turkish population, since it is very important to confirm the observed genetic association in various different populations. Screening of 101 ALS patients and 99 healthy controls with restriction enzyme analysis and DNA sequencing did not reveal any statistically significant association of these genes with ALS in our study population. But a possible novel mutation in the ANG gene was identified in a juvenile ALS patient. This is a preliminary result, which has to be verified by further analysis of the patient and his family.