Although TG p.L1791Cfs*12 and p.R296* are pathogenic, both were inherited in double heterozygosity with the novel TPO variant p.E799Q and the likely benign TSHR variant c.692 + 1_692 + 4delGTGA, respectively; therefore, the relative contributions of the two mutations are not clear, and it is also possible that an undetected, non-exonic TG mutation on the other allele is contributing to CH. The gene discussed is TPO; the disease is cyclic hematopoiesis.