Neurobiology of Aging 30 (2009) 842–844 Negative results Is erythropoietin gene a modifier factor in amyotrophic lateral sclerosis? Serena Ghezzi a,1 , Roberto Del Bo a,∗,1 , Marina Scarlato a , Martina Nardini a , Cecilia Carlesi b , Alessandro Prelle a , Stefania Corti a , Michelangelo Mancuso b , Chiara Briani c , Gabriele Siciliano b , Luigi Murri b , Nereo Bresolin a,d , Giacomo Pietro Comi a a Dino Ferrari Centre, Department of Neurological Sciences, University of Milan, IRCCS Foundation Ospedale Maggiore Policlinico Mangiagalli and Regina Elena, Padiglione Ponti. Via F. Sforza 35, 20122 Milano, Italy b Department of Neuroscience, Neurological Institute, University of Pisa, Pisa, Italy c Department of Neurosciences, University of Padua, Padua, Italy d IRCCS E. Medea, Associazione La Nostra Famiglia, Bosisio Parini, Italy Received 24 May 2007; accepted 14 August 2007 Available online 20 September 2007 Abstract To investigate the role of erythropoietin (EPO) as genetic determinant in the susceptibility to sporadic amyotrophic lateral sclerosis (SALS). We sequenced a 259-bp region spanning the 3 ′ hypoxia-responsive element of the EPO gene in 222 Italian SALS patients and 204 healthy subjects, matched for age and ethnic origin. No potentially causative variation was detected in SALS subjects; in addition, two polymorphic variants (namely C3434T and G3544T) showed the same genotype and haplotype frequencies in patients and controls. Conversely, a weak but significant association between G3544T and age of disease onset was observed (p = 0.04). Overall, our data argue against the hypothesis of EPO as a genetic risk factor for motor neuron dysfunction, at least in Italian population. However, further studies on larger cohort of patients are needed to confirm the evidence of EPO gene as modifier factor. © 2007 Elsevier Inc. All rights reserved. Keywords: Amyotrophic lateral sclerosis; Erythropoietin; Genetic risk factor; Susceptibility; Motorneuron degeneration Amyotrophic lateral sclerosis (ALS) is an adult-onset neu- rodegenerative disease characterized by progressive loss of motor neurons. Approximately 10% of ALS cases are famil- iar, with the remaining being sporadic. Although a specific genetic alteration responsible for sporadic ALS cases is still lacking, a number of modifier loci and associated genes have been identified (Schymick et al., 2007). Recently, different hypoxia responsive genes as vascular endothelial growth fac- tor (VEGF) and angiogenin (ANG) have been linked to ALS. Both share a neuroprotective role and their involvement in ∗ Corresponding author. Tel.: +39 0255033843; fax: +39 0250320430. E-mail address: roberto.delbo@unimi.it (R. Del Bo). 1 These two authors equally contributed to the present work. ALS is not yet clear if is a consequence of the oxidative stress itself and or if they have an active role in establishing the neurodegenerative process. From a genetic point of view, controversial results about VEGF polymorphisms role have been observed in different populations (Chen et al., 2006; Lambrechts et al., 2003), whereas sequencing of ANG gene allowed to identify 7 missense mutations in 15 ALS patients (Greenway et al., 2006), not confirmed in two cohorts of Italian ALS patients (Corrado et al., 2007; Del Bo et al., 2006). In line with the other two hypoxia related genes, a role in motor neuron disease has been proposed also for the erythropoietin gene (EPO). In fact, a part from its role in erythropoiesis, EPO exerts neuroprotective effects follow- ing ischemic, hypoxic, metabolic neurotoxic or excitotoxic 0197-4580/$ – see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.neurobiolaging.2007.08.008