A polymorphism in metallothionein 1A (MT1A) is associated with cadmium-related excretion of urinary beta 2‐microglobulin

► Cadmium is toxic to the kidney but the susceptibility differs between individuals. ► The toxic effect of cadmium is scavenged by metallothioneins. ► A common variant of metallothionein 1A was genotyped in 512 cadmium exposed humans. ► Variant carriers of this polymorphism showed more kidney damage from cadmium. ► The frequency of these variants needs to be taken into account in risk assessment.