PROK2 and Kallmann syndrome: Compared to subjects with other known genetic causes of nCHH KISS1R (mean (±SD) FSH/LH = 3.2±2.4), GNRHR (mean FSH/LH = 1.3±0.5) mutations or Kallmann syndrome (KAL1:mean FSH/LH = 1.2±0.6), FGFR1 (mean FSH/LH = 1.5±0.5) and PROK2 or PROKR2 mutations (mean FSH/LH = 1.7±1.4)(Information S1) and to 32 patients with nCHH (mean FSH/LH = 1.2±0.8) and no identified genetic anomalies, patients with TAC3/TACR3 mutations had very significantly (p<0.001 for each comparison, see Fig. 4A) higher FSH/LH ratios (mean FSH/LH =  23.6±22.4).