GNRH1 and cartilage-hair hypoplasia: Supraphysiological FSH serum concentrations that are likely to occur with such a regimen are not likely to be detrimental, due to the localization of the FSHR only on Sertoli cells and due to observations for example in moderate preterm mini-puberty, when such enhanced stimulation occurs without side effects. While replacement of minipuberty can be performed using either pulsatile GnRH or gonadotropins male infants with isolated CHH, replacement of CHH in boys with combined pituitary hormone deficiencies (CPHD) will be successful only with the use of gonadotropins.