We found genome-wide significant association of two loci, both involved in apoptosis, with thyroid volume of HT patients: rs7212416 inside apoptosis-antagonizing transcription factor AATF (P = 8.95 × 10−9) and rs10738556 near chromatin-remodeling SMARCA2 (P = 2.83 × 10−8). The gene discussed is SMARCA2; the disease is hematocrit.