Investigation of the second family also showed autosomal recessive transmission and demonstrated that the gonadotropin deficiency could be corrected by pulsatile GnRH administration, lending further weight to the concept originally proposed by Seminara et al [13], [16], namely that the gonadotropin deficiency in these patients is secondary to their GnRH deficiency as been demonstrated in several animal models [44]. This evidence concerns the gene GNRH1 and Gonadotropin deficiency.