Fig. 1.

Clinical images from patients with the N567K mutation in the catalytic domain of OGT. (A) Picture of twin 1 showing dysmorphic features at age 4 y (Left) and 10 y (Right). (B) Picture of twin 2 showing dysmorphic features at age 4 y (Left) and 10 y (Right). (C) Schematic diagram of OGT highlighting the TPRs, TPR-like repeat, N-Cat, and C-Cat, and the site of N567K, as well as the previously identified XLID-associated mutations in OGT. The Inset shows the sequence alignment of the region encompassing the N567K mutation across the commonly used model organisms. N-Cat and C-Cat: N- and C-terminal lobes of OGT catalytic domain; TPR: tetratricopeptide repeat domain; TLR: tetratricopeptide repeat-like domain.