This study found a significantly high genetic correlation (rg = 0.637) between the two diseases, as well as causal variants for both ALS and FTD at 9p21.2 (MOB3B, IFNK, and C9orf72) and 19p13.11 (UNC13A), which had previously been identified as overlapping disease-associated regions31,32. Here, UNC13A is linked to amyotrophic lateral sclerosis.