The rank order of potentially causative genes in our cohort is comparable with other studies, because TSHR mutations commonly cause non-autoimune hyperthyrotropinemia, TPO mutations frequently underlie dyshormonogenesis, and DUOX2 mutations are a common cause of either mild/transient CH or TSH resistance (6, 25, 28, 31, 32). The gene discussed is DUOX2; the disease is cyclic hematopoiesis.