The intronic variant chr16-205386-G-A (located within LUC7L and within ~30KB of the alpha haemoglobin genes HBA1 and HBA2) was identified as a causal variant for a range of red cell traits in both SAS cohorts only, in keeping with its ultra-rare frequency in non-SAS populations—although the effect has been previously reported in UKB SAS individuals, we add confidence to this result by replicating in a far larger cohort of people of SAS ancestry11. Here, HBA2 is linked to SATB2 associated disorder.