tRNA methyltransferase 10 homologue A (TRMT10A) mutation in a Chinese patient with diabetes, insulin resistance, intellectual deficiency and microcephaly

Introduction Loss-of-function mutations in tRNA methyltransferase 10 homologue A (TRMT10A), a tRNA methyltransferase, have recently been described as a monogenic cause of early-onset diabetes with microcephaly, epilepsy and intellectual disability. Research design and methods We report a Chinese young patient who was diagnosed with diabetes mellitus as a result of aTRMT10Amutation. Results A homozygous mutation c.496-1G>A inTRMT10Awas identified using targeted next-generation sequencing and confirmed by PCR/Sanger sequencing. In addition to being diagnosed with diabetes, the patient also has microcephaly and intellectual deficiency. The diabetes was due to marked insulin resistance and responded very well to metformin treatment. Conclusion Our case is the first report in the Asian population. It adds to current knowledge ofTRMT10Arelated with young-onset non-insulin-dependent diabetes and confirms the a single previous report of insulin resistance in this syndrome. Genomic testing should be considered in children with non-insulin-dependent diabetes with intellectual disability and microcephaly. A clear genetic diagnosis is helpful for early detection and treatment addressing insulin resistance.