Patients are homozygous for a nonsense mutation in TRMT10A and lose TRMT10A expression.

(A) Sanger sequencing at the level of the mutation identified by whole exome sequencing in proband. The mutation c.379 G>A; p.Arg127Stop changes a CGA codon (Arginine) into a TGA codon (Stop), and is found homozygous in the proband (P), heterozygous in unaffected mother (M) and absent in an unrelated control subject (C). (B) TRMT10A protein and (C) mRNA expression was examined by Western blot and real-time PCR in lymphoblast from three controls (CT1-3), two patients homozygous for the nonsense mutation (P1 and P2) and one heterozygous carrier (HET). α-Tubulin was used as loading control and TRMT10A mRNA expression was normalized to the geometric mean of the reference genes GAPDH, actin and OAZ1 expression.