Defective synaptic development and function underlies the aetiology of motor neuron disease (MND). We have functionally interrogated MND GWAS, exome, and synaptic candidates to identify genes that regulate MND and neuromuscular development in vivo.  This has been achieved through a phenotype screen in Drosophila, using the GMR-Gal4 driver for the eye-specific knockdown of candidate genes. We have thus far evaluated 210 of 500 candidate genes and found 51 (a hit rate of 25%) genes which affect the development, organisation, size or lead to necrosis of the ommatidia (optical units of compound eyes in Drosophila). In the future, we will continue this process and further characterize positive hits using morphological and electrophysiological assessment. We will also conduct a suppression study using TDP43 and c9orf72 disease models to identify potential MND drug targets.