phenotype affects entity negative regulation of synapse assembly synaptogenesis variant neurite development variant inhibition of synaptogenesis defective WBPhenotype:0001798 C_elegans_phenotype_ontology The processes that inhibit the location or frequency of formation of synapses are downregulated resulting in the formation of synapses or synapse-like structures in areas of the neuron that are typically devoid of synapses in control animals.