SLC30A5 and Failure to thrive: Altogether, we demonstrate that a bi‐allelic in‐frame deletion missense variant in the zinc carrier SLC305A (ZnT5) results in lower cytosolic Zn2+ concentrations, causing a severe syndrome of neonatal non‐progressive mostly axial yet also limb hypotonia with failure to thrive, and respiratory failure culminating in early death within the first year of life.