In keeping with previous findings, we have found genotype-phenotype correlations in risk genes for ALS, the most striking of which is the finding of insertion in the ERBB4 gene in 71.4% of people with respiratory onset ALS compared with 46.4% of those with non-respiratory onset, and just 25.3% of the general population. Here, ERBB4 is linked to amyotrophic lateral sclerosis.