Abstract:
There are 3 physiological waves of central hypothalamic-pituitary-gonadal (HPG) axis activity over the lifetime. The first occurs during fetal life, the second-termed \"mini-puberty\"-in the first months after birth, and the third at puberty. After adolescence, the axis remains active all through adulthood. Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by a deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) secretion or action. In cases of severe CHH, all 3 waves of GnRH pulsatility are absent. The absence of fetal HPG axis activation manifests in around 50% of male newborns with micropenis and/or undescended testes (cryptorchidism). In these boys, the lack of the mini-puberty phase accentuates testicular immaturity. This is characterized by a low number of Sertoli cells, which are important for future reproductive capacity. Thus, absent mini-puberty will have detrimental effects on later fertility in these males. The diagnosis of CHH is often missed in infants, and even if recognized, there is no consensus on optimal therapeutic management. Here we review physiological mini-puberty and consequences of central HPG axis disorders; provide a diagnostic approach to allow for early identification of these conditions; and review current treatment options for replacement of mini-puberty in male infants with CHH. There is evidence from small case series that replacement with gonadotropins to mimic \"mini-puberty\" in males could have beneficial outcomes not only regarding testis descent, but also normalization of testis and penile sizes. Moreover, such therapeutic replacement regimens in disordered mini-puberty could address both reproductive and nonreproductive implications.
摘要:
一生中,下丘脑-垂体-性腺(HPG)轴活动有3个生理波。第一次发生在胎儿时期,第二个被称为“迷你青春期”-在出生后的头几个月,第三个在青春期。青春期之后,轴在整个成年期间保持活跃。先天性低促性腺激素性腺功能减退(CHH)是一种罕见的遗传性疾病,其特征是下丘脑促性腺激素释放激素(GnRH)分泌或作用不足。在严重CHH的情况下,所有3波GnRH搏动都不存在。胎儿HPG轴激活的缺失在约50%的男性新生儿中表现出微阴茎和/或睾丸未降(隐睾)。在这些男孩中,迷你青春期阶段的缺乏加剧了睾丸的不成熟。其特点是支持细胞数量少,这对未来的生殖能力很重要。因此,缺乏青春期会对这些男性的后期生育能力产生不利影响。婴儿常漏诊CHH,即使被认可,关于最佳治疗管理尚无共识.在这里,我们回顾了生理性小青春期和中枢HPG轴疾病的后果;提供一种诊断方法,以允许早期识别这些疾病;并回顾了CHH男性婴儿替代小青春期的当前治疗方案。小病例系列有证据表明,用促性腺激素替代男性的“小青春期”不仅对睾丸下降有好处,而且睾丸和阴茎大小也正常化。此外,这样的治疗性替代方案在小青春期失调可以解决生殖和非生殖的影响。