phenylephrine-hydrochloride and Hypogonadism

The reproductive axis is controlled by a network of gonadotropin-releasing hormone (GnRH) neurons born in the primitive nose that migrate to the hypothalamus alongside axons of the olfactory system. The observation that congenital anosmia (inability to smell) is often associated with GnRH deficiency in humans led to the prevailing view that GnRH neurons depend on olfactory structures to reach the brain, but this hypothesis has not been confirmed.. The objective of this work is to determine the potential for normal reproductive function in the setting of completely absent internal and external olfactory structures.. We conducted comprehensive phenotyping studies in 11 patients with congenital arhinia. These studies were augmented by review of medical records and study questionnaires in another 40 international patients.. All male patients demonstrated clinical and/or biochemical signs of GnRH deficiency, and the 5 men studied in person had no luteinizing hormone (LH) pulses, suggesting absent GnRH activity. The 6 women studied in person also had apulsatile LH profiles, yet 3 had spontaneous breast development and 2 women (studied from afar) had normal breast development and menstrual cycles, suggesting a fully intact reproductive axis. Administration of pulsatile GnRH to 2 GnRH-deficient patients revealed normal pituitary responsiveness but gonadal failure in the male patient.. Patients with arhinia teach us that the GnRH neuron, a key gatekeeper of the reproductive axis, is associated with but may not depend on olfactory structures for normal migration and function, and more broadly, illustrate the power of extreme human phenotypes in answering fundamental questions about human embryology.

Topics: Abnormalities, Multiple; Adolescent; Adult; Aged; Child; Child, Preschool; Cohort Studies; Female; Follicle Stimulating Hormone; Gonadotropin-Releasing Hormone; Gonads; Humans; Hypogonadism; Infant; Luteinizing Hormone; Male; Middle Aged; Neurogenesis; Neurons; Nose; Olfaction Disorders; Olfactory Pathways; Organ Size; Young Adult

Topics: Adolescent; Diagnosis, Differential; Estrogen Replacement Therapy; Female; Humans; Hypogonadism; Kallmann Syndrome; Nose; Olfaction Disorders

The association of anosmia and congenital hypogonadotropic hypogonadism (CHH) is well described; however, congenital arhinia is a malformation associated with CHH that occurs much more rarely. There have been three reports of male patients with hypogonadism and congenital arhinia in the literature to date. We present the first case of arhinia associated with CHH in a female patient. A 14 years and 8 months female with congenital arhinia presented with delayed puberty. Physical examination and laboratory evaluation were consistent with hypogonadotropic hypogonadism. She had no other hormone deficiencies and brain magnetic resonance imaging demonstrated a normal pituitary gland. Abdominal ultrasound showed a prepubertal uterus and ovaries. She was subsequently started on sex steroid treatment to induce secondary sexual characteristics. This case demonstrates that abnormalities of nasal development may provide an early diagnostic clue to hypogonadotropic hypogonadism, particularly in female patients who would not manifest classic signs of CHH in infancy (micropenis and cryptorchidism). Early diagnosis of CHH and timely initiation of sex steroid therapy is important to prevent comorbidities related to pubertal delay.

Topics: Adolescent; Congenital Abnormalities; Female; Humans; Hypogonadism; Male; Nose; Prognosis; Sexual Maturation; Testosterone

Olf/Ebf transcription factors have been implicated in numerous developmental processes, ranging from B-cell development to neuronal differentiation. We describe mice that carry a targeted deletion within the Ebf2 (O/E3) gene. In Ebf2-null mutants, because of defective migration of gonadotropin releasing hormone-synthesizing neurons, formation of the neuroendocrine axis (which is essential for pubertal development) is impaired, leading to secondary hypogonadism. In addition, Ebf2(-/-) peripheral nerves feature defective axon sorting, hypomyelination, segmental dysmyelination and axonal damage, accompanied by a sharp decrease in motor nerve conduction velocity. Ebf2-null mice reveal a novel genetic cause of hypogonadotropic hypogonadism and peripheral neuropathy in the mouse, disclosing an important role for Ebf2 in neuronal migration and nerve development.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Movement; DNA-Binding Proteins; Female; Gene Targeting; Gonadotropin-Releasing Hormone; Hypogonadism; Hypothalamus; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nasal Mucosa; Neural Conduction; Neurons; Nose; Sciatic Nerve; Seminiferous Tubules; Transcription Factors

Two males, 9-11 and 29-31 years of age, with severe hypoplasia of the nose, hypoplasia of the eyes, sensory abnormalities of taste and smell, and hypogonadism were studied. The nasal septum, cribriform plates and foramina of the vomeronasal (vn) nerves were demonstrated in both; the capsule of the vn organ was shown in one. Their nasal skeleton, demonstrated by tomoradiography, had grown in early embryological form. The nose was not patent in either patient. In both, the cranial vaults, orbits, epipharynges, and oral cavities were indented toward the hypoplastic nasal composite and the peripheral dimensions of their faces were normal for their respective ages. Each patient had impaired visual function with cataracts and colobomata. Each was unable to recognize the smell of any vapor (Type I hyposmia), and had severe impairment of recognition of any tastant (recognition hypogeusia); detection of vapors and of tastants were in appropriate anatomical areas. Each was unable orally to recognize standard plastic forms (astereognosis) though each could recognize the forms manually. Each patient had bilateral inguinal hernias, one or two undescended testes, and hypogonadotrophic hypogonadism. These patients do not fall within the spectrum of arrhinencephaly because of the presence of medial structure of attachment of the falx cerebri and because of their normal intelligence. Distinction of patients with this pattern of abnormalities from arrhinencephaly is important by reason of their potentiality of normal mental development. We hypothesize that their abnormalities resulted from an embryological disruption that occurred in the first trimester of pregnancy. The embryogenesis of the nasal composite is presumed to have been adequate for reciprocal induction of the anlagen of the forebrain. Development of their faces to normal peripheral dimensions indicates that the nasal composite is not essential for gross facial enlargement.

Topics: Adult; Child; Eye Abnormalities; Facial Bones; Gonadotropins; Humans; Hypogonadism; Male; Nose; Olfaction Disorders; Skull; Stereognosis; Taste Disorders; Tomography, X-Ray; Vision Disorders