DPH2

The DPH2 protein is required for diphthamide biosynthesis, a post-translational modification of histidine in elongation factor 2, where it facilitates reduction of the iron-sulfur cluster in the DPH1 subunit. Mutations cause autosomal recessive developmental delay with short stature, dysmorphic facial features, and sparse hair. The gene shows low constraint against loss-of-function variants (pLI 0.00001), consistent with its recessive inheritance pattern.