The tRNA methyltransferase 10 homologue A (TRMT10A) gene encodes a tRNA methyl transferase, and biallelic loss of function mutations cause a recessive syndrome of intellectual disability, microcephaly, short stature and diabetes. A case with intellectual disability and distinctive features including microcephaly was admitted. She was diagnosed with epilepsy at 2.5 years old. At 3.6 years of age, severe short stature related to growth hormone deficiency was detected. She had an incidental diagnosis of diabetes at age 11.4 years that was negative for diabetes antibodies with persistent C-peptide level and treated with metformin. Spontaneous puberty did not begin until 15.7 years of age and she was found to have primary ovarian failure. A homozygous p.Arg127* mutation in TRMT10A was detected. In addition to the typical clinical features that characterize TRMT10A syndrome we observed in our patient an unusual form of impaired glucose
metabolism that was presented in early childhood with hypoglycemia followed by diabetes in late childhood. Growth hormone deficiency and primary ovarian failure may also be additional findings of this syndrome. Patients with slow onset diabetes that are negative for auto-antibodies and have extra-pancreatic features should be tested for all known subtypes monogenic diabetes.