Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease with a largely unknown pathogenesis. The most common gene mutation in both familial and sporadic ALS is the C9orf72 repeat expansion. Investigating asymptomatic carriers of this mutation might give more insight into possible preclinical brain alterations. Using whole brain 31P MRSI at 7T, glycerophosphoethanolamine-to-phosphocreatine ratio (GPE/PCr) and uridine diphosphoglucose-to-phosphocreatine ratio (UDPG/PCr) were found to be higher in a number of brain regions in asymptomatic carriers compared with asymptomatic non-carriers. The increased GPE/PCr and UDPG/PCR might respectively indicate an increased catabolism of the cell membranes and an imbalance of energy metabolism.