Taken together these results suggest that SALL1 variants could cause TBS either by affecting the ability of SALL1 to interact with SALL proteins and DNA through a resistance to nonsense-mediated decay and a dominant negative effect (truncating variants located downstream of the glutamine-rich domain), or through a dosage effect (deletion or truncating variants located upstream of the glutamine-rich domain). Here, SALL1 is linked to Townes-Brocks syndrome.