Studies of the pituitary-Leydig cell axis in young men with hypogonadotropic hypogonadism and hyposmia: comparison with normal men, prepuberal boys, and hypopituitary patients

Correlations Among Genotype and Outcome in Chinese Male Patients With Congenital Hypogonadotropic Hypogonadism Under HCG Treatment

BACKGROUND

Congenital hypogonadotropic hypogonadism (CHH) is a genetically heterogeneous disorder characterized by absent or incomplete puberty and infertility, and heterogeneous responses are often observed during treatment.

AIM

To investigate the role of CHH-associated variants in patients with CHH with poor responses to human chorionic gonadotropin (hCG).

METHODS

This retrospective study investigated 110 Chinese male patients with CHH undergoing genetic analysis and hCG treatment. CHH-associated rare sequence variants (RSVs) were identified by using a tailored next-generation sequencing panel and were interpreted in accordance with the American College of Medical Genetics and Genomics criteria. Clinical characteristics were recorded, and Kyoto Encyclopedia of Genes and Genomes analysis was conducted to assess pathways enriched in protein networks implicated in poor responses.

OUTCOMES

The outcomes include testicular volume, serum hormonal profiles, parameters of semen analysis, pathogenicity classification, and pathway enrichment.

RESULTS

Among the 110 patients, 94.55% achieved normal serum testosterone and 54.55% achieved seminal spermatozoa appearance (SSA). PLXNB1, ROBO3, LHB, NRP2, CHD7, and PLXNA1 RSVs were identified in patients who had an abnormal serum testosterone level during treatment. In spermatogenesis, the number of CHH-associated RSVs was not significantly strongly associated with delayed SSA. After pathogenicity classification, pathogenic/likely pathogenic (P/LP) RSVs were identified in 30% (33/110) of patients. Patients with P/LP RSVs showed delayed SSA compared with noncarriers, and P/LP PROKR2 RSVs showed the strongest association (48, 95% CI: 34.1-61.9 months, P = .043). Enriched pathways implicated in delayed SSA included neuroactive ligand-receptor interaction; Rap1, MAPK, PI3K-Akt signaling; and regulation of actin cytoskeleton.

CLINICAL IMPLICATIONS

Male patients with CHH harboring P/LP PROKR2 RSVs should be aware of a high probability of poor responses to hCG; If these patients desire fertility, it might be better to recommend hCG/human menopausal gonadotropin, hCG/recombinant follicle-stimulating hormone, or pulsatile GnRH administration before treatments start or as early as possible.

STRENGTHS & LIMITATIONS

Strengths are the standardized regimen and extensive follow-up (median time of 40 months). However, included patients in the study voluntarily chose hCG treatment because of the burden of drug cost and/or little fertility desire. Therefore, human menopausal gonadotropin or follicle-stimulating hormone was not added to this cohort. Our observed correlations should be further verified in patients with CHH undergoing other treatments.

CONCLUSION

Among all P/LP RSVs, P/LP PROKR2 RSVs might correlate with poor responses in CHH under hCG treatment; our study supports the pathogenicity assessment of American College of Medical Genetics and Genomics criteria in genetic counseling, to improve management of patients with CHH. Chen Y, Sun T, Niu Y, et al. Correlations AmongGenotype and Outcome in Chinese Male Patients WithCongenital Hypogonadotropic Hypogonadism Under HCG Treatment. J Sex Med 2020;17:645-657.

Treatment preferences and outcome in male hypogonadotropic hypogonadism: an Indian perspective

This retrospective study assessed treatment preferences and outcome with testosterone or HCG / HCG-FSH combination in Indian male idiopathic hypogonadotropic hypogonadism (IHH) subjects (n = 31) above 18 years of age. 38.7% of IHH study subjects had no fertility plans and chose 3 monthly intramuscular testosterone undecanoate. 73.7% of subjects with fertility plans chose human chorionic gonadotropin (HCG) alone due to cost considerations. Spermatogenesis occurred in 21.4% on HCG alone and 60% of subjects on HCG with follicle-stimulating hormone (FSH) combination. Treatment failure is higher than published Western rates. FSH and HCG combination regimen is costly but superior to HCG alone. However, treatment failure still persists, suggesting unknown testicular defect in IHH.

Clinical, endocrinological, and molecular characterization of Kallmann syndrome and normosmic idiopathic hypogonadotropic hypogonadism: a single center experience

PURPOSE

Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is classified as Kallmann syndrome (KS) with anosmia and normosmic idiopathic hypogonadotropic hypogonadism (nIHH). This study was undertaken to investigate the clinical, endocrinological, and molecular characteristics in Korean patients with KS and nIHH.

METHODS

Twenty-six patients from 25 unrelated families were included. Their clinical, endocrinological, and radiological findings were analyzed retrospectively. Mutation analysis of the GNRH1, GNRHR, KISS1, KISS1R, PROK2, PROKR2, TAC3, TACR3, FGF8, FGFR1, and KAL1 genes was performed in all patients. CHD7 and SOX10 were analyzed in patients with CHARGE (Coloboma, Heart defects, choanae Atresia, Growth retardation, Genitourinary abnormality, Ear abnormality) features or deafness.

RESULTS

Of the 26 patients, 16 had KS and 10 had nIHH. At diagnosis, mean chronologic age was 18.1 years in males and 18.0 years in females; height SDS were -0.67±1.35 in males, -1.12±1.86 in females; testis volume was 2.0±1.3 mL; and Tanner stage was 1.5. There were associated anomalies in some of the KS patients: hearing loss (n=6) and congenital heart disease (n=4). Absence or hypoplasia of the olfactory bulb/sulci was found in 84.62% of patients with KS. Molecular defects in KAL1, SOX10, and CHD7 were identified in 5 patients from 4 families (16.0%, 4/25 pedigrees). After sex hormone replacement therapy, there were improvement in sexual characteristics and the sexual function.

CONCLUSION

This study described the clinical, endocrinological, and molecular genetic features in IGD patients in Korea. Although the mutation screening was performed in 10 genes that cause IGD, molecular defects were identified in relatively small proportions of the cohort.

Sex steroids, precursors, and metabolite deficiencies in men with isolated hypogonadotropic hypogonadism and panhypopituitarism: a GCMS-based comparative study

CONTEXT

Both testicular and adrenal steroid secretions are impaired in men with panhypopituitarism (Hypo-Pit), whereas only testicular steroid secretion is impaired in men with isolated gonadotropin deficiency (IHH) caused by normosmic congenital hypogonadotropic hypogonadism or Kallmann syndrome.

OBJECTIVE

The objective of the study was to compare the serum levels of sex steroids, precursors, and metabolites between men with complete IHH and those with Hypo-Pit.

PATIENTS

We studied 42 healthy men, 16 untreated men with IHH (normosmic congenital hypogonadotropic hypogonadism/Kallmann syndrome) and 23 men with Hypo-Pit (14 with craniopharyngioma, 9 with congenital hypopituitarism) receiving hydrocortisone, thyroxine, and GH replacement therapy but not T.

METHODS

Gas chromatography/mass spectrometry (GCMS) was used to measure the serum levels of sex steroids [T, dihydrotestosterone (DHT), and estradiol (E2)], their precursors (pregnenolone, 17-hydroxypregnenolone, dehydroepiandrosterone, androstenediol, progesterone, 17-hydroxyprogesterone, and androstenedione), and their metabolites (androsterone, estrone, and estrone sulfate) as well as pregnenolone and dehydroepiandrosterone sulfate esters.

RESULTS

All the above-mentioned steroids, and notably T, DHT, and E2, were significantly lower in IHH patients than in controls but remained well above the detection limit of the relevant assays. In Hypo-Pit men, all these steroids were dramatically and significantly lower than in IHH. Interestingly, T, DHT, and E2, as well as pregnenolone and dehydroepiandrosterone sulfate esters, were undetectable or barely detectable in the Hypo-Pit men.

CONCLUSIONS

Steroid deficiencies are marked but partial in men with complete IHH. In contrast, men with Hypo-Pit have a very severe overall steroid deficiency. These deficiencies could affect health and quality of life.

Predictors of pilosebaceous unit responsiveness to testosterone therapy in patients with hypogonadotrophic hypogonadism

Testosterone replacement therapy is the mainstay of treatment in male patients with isolated hypogonadotrophic hypogonadism (HH) to achieve virilisation. However, responsiveness of pilosebaceous unit (PSU) to testosterone replacement therapy in these patients is quite variable. Androgen action is inversely proportional to the number of CAG repeats in exon 1 of androgen receptor gene; therefore, we hypothesised that CAG repeat length contributes to testosterone responsiveness in patients with HH. The CAG repeat length in 21 well-virilised men (hair score > 30, responders) and 25 poorly virilised men (hair score ≤ 30, non-responders) with HH on optimal testosterone replacement therapy at least for a period of 1 year was analysed. Serum LH, FSH, testosterone and 17 β oestradiol were estimated. Polymerase chain reaction (PCR) amplification of exon 1 of androgen receptor gene was performed from genomic DNA, and these PCR-amplified products were sequenced for the number of CAG repeats. The difference between number of CAG repeats in responders and non-responders was statistically significant (19.19 ± 3.25 and 22.24 ± 2.65, P = 0.001) and showed a strong negative correlation with total body hair score (r = -0.538 and P = 0.0001). In conclusion, these results suggest that the number of CAG repeats influences the responsiveness of PSU to testosterone treatment in patients with HH.

Clues to an early diagnosis of Kallmann syndrome

Kallmann syndrome (KS) is defined by the association of idiopathic hypogonadotropic hypogonadism and anosmia/hyposmia. Diagnosis is frequently delayed, however, because hypogonadotropic hypogonadism is usually not apparent until puberty and individuals with anosmia/hyposmia are often unaware of this sensory deficit. Mutations in at least six genes have been associated with KS; however, the sensitivity of molecular testing is only about 30% and, therefore, the diagnosis is largely based on clinical findings. We describe the findings in six individuals with KS, which demonstrate the utility of associated anomalies in making this diagnosis. Analysis of our case series and literature review suggests the consideration of KS for males with microphallus and/or cryptorchidism and for any patient with hearing loss, renal agenesis, and/or synkinesis. Conversely, patients with features of KS should have an audiology evaluation and a renal ultrasound.

Congenital idiopathic hypogonadotropic hypogonadism: evidence of defects in the hypothalamus, pituitary, and testes

CONTEXT

Idiopathic hypogonadotropic hypogonadism (IHH) with normal smell (normosmic IHH) or anosmia (Kallmann syndrome) is associated with defects in the production or action of GnRH. Accordingly, most IHH patients respond to physiological pulsatile GnRH replacement by normalizing serum LH, FSH, and testosterone (T) levels and achieving gametogenesis; some patients, however, show atypical responses. Interestingly, several IHH-associated genes are expressed in multiple compartments of the hypothalamic-pituitary-gonadal axis.

OBJECTIVE

The aim of the study was to investigate whether the clinical, biochemical, or genetic characteristics of IHH men with atypical responses to GnRH indicate alternative or additional defects in the hypothalamic-pituitary-gonadal axis.

SUBJECTS

We studied 90 IHH men undergoing long-term pulsatile GnRH treatment over 30 yr.

DESIGN AND SETTING

We conducted a retrospective study of response to GnRH at a Clinical Research Center.

INTERVENTIONS

Physiological regimens of pulsatile s.c. GnRH were administered for at least 12 months. Dose-response studies using i.v. GnRH pulses assessed the pituitary LH response.

MAIN OUTCOME MEASURES

We measured serum T, LH, FSH, and inhibin B levels, sperm in ejaculate, and determined the sequence of IHH-associated genes.

RESULTS

Twenty-six percent of subjects displayed atypical responses to GnRH: 1) 10 remained hypogonadotropic and hypogonadal, demonstrating pituitary and testicular defects; 2) eight achieved spermatogenesis and normal T but only with hypergonadotropism, indicating impaired testicular responsiveness to gonadotropins; and 3) five remained azoospermic despite achieving adult testicular volumes and normal hormonal profiles, suggesting primary defects in spermatogenesis. Mutations were identified only in KAL1 across groups.

CONCLUSION

In addition to hypothalamic GnRH deficiency, IHH men can have primary pituitary and/or testicular defects, which are unmasked by GnRH replacement.

Síndrome de Kallmann: uma revisão histórica, clínica e molecular

A síndrome de Kallmann (SK) é a associação de hipogonadismo hipogonadotrófico (HH) e anosmia descrita por Maestre de San Juan, em 1856, e caracterizada como condição hereditária por Franz Josef Kallmann, em 1944. Muitos aspectos de sua patogenia, variabilidade fenotípica e genotípica foram desvendados nos últimos 15 anos. Conseqüentemente, tem sido difícil manter-se atualizado frente à rapidez que o conhecimento dessa condição é gerado. Nesta revisão, resgatamos aspectos históricos pouco conhecidos sobre a síndrome e seus descobridores; incorporamos novas descobertas relacionadas à embriogênese dos neurônios olfatórios e produtores de GnRH. Esse processo é fundamental para compreender a associação de hipogonadismo e anosmia; descrevemos a heterogeneidade fenotípica e genotípica, incluindo mutações em cinco genes (KAL-1, FGFR1, PROKR2, PROK2 e NELF). Para cada gene, discutimos a função da proteína codificada na migração e maturação dos neurônios olfatórios e GnRH a partir de estudos in vitro e modelos experimentais e descrevemos características clínicas dos portadores dessas mutações.

Functional MRI of congenital hyposmia: brain activation to odors and imagination of odors and tastes

PURPOSE

Our goal was to use functional MRI (fMRI) to define brain activation in response to odors and imagination ("memory") of odors and tastes in patients who never recognized odors (congenital hyposmia).

METHOD

Functional MR brain scans were obtained in nine patients with congenital hyposmia using multislice echo planar imaging (EPI) in response to odors of amyl acetate, menthone, and pyridine and to imagination ("memory") of banana and peppermint odors and to salt and sweet tastes. Functional MR brain scans were compared with those in normal subjects and patients with acquired hyposmia. Activation images were derived using correlation analysis, and ratios of areas of brain activated to total and hemispheric brain areas were calculated. Total and hemispheric activated pixel counts were used to quantitate regional brain activation.

RESULTS

Brain activation in response to odors was present in patients with congenital hyposmia. Activation was significantly lower than in normal subjects and patients with acquired hyposmia and did not demonstrate differential vapor pressure-dependent detection responsiveness or odor response lateralization. Regional activation localization was in anterior frontal and temporal cortex similar to that in normal subjects and patients with acquired hyposmia. Activation in response to presented odors was diverse, with a larger group exhibiting little or no activation with localization only in anterior frontal and temporal cortex and a smaller group exhibiting greater activation with localization extending to more complex olfactory integration sites. "Memory" of odors and tastes elicited activation in the same central nervous system (CNS) regions in which activation in response to presented odors occurred, but responses were significantly lower than in normal subjects and patients with acquired hyposmia and did not lateralize.

CONCLUSION

Odors induced CNS activation in patients with congenital hyposmia, which distinguishes olfaction from vision and audition since neither light nor acoustic stimuli induce CNS activation. Odor activation localized to anterior frontal and temporal cortex, consistent with the hypothesis that olfactory pathways are hard-wired into the CNS and that further pathways are undeveloped with primary olfactory system CNS connections but lack of secondary connections. However, some patients exhibited greater odor activation with response localization extending to cingulate and opercular cortex, indicating some olfactory signals impinge on and maintain secondary connections consistent with similar functions in vision and audition. Activation localization of taste "memory" to anterior frontal and temporal cortex is consistent with CNS plasticity and cross-modal CNS reorganization as described for vision and audition. Thus, there are differences and similarities between olfaction, vision, and audition, the differences dependent on unique qualities of olfaction, perhaps due to its diffuse, primitive, fundamental role in survival. Response heterogeneity to odors may reflect heterogeneous genetic abnormalities, independent of anatomic or hormonal changes but dependent on molecular abnormalities in growth factor function interfering with growth factor/stem cell interactions. Patients with congenital hyposmia offer an unique model system not previously explored in which congenital smell lack as measured by fMRI is reflective of congenital dysfunction of a major sensory system.

Central Hypogonadism: Distinguishing Idiopathic Low Testosterone from Pituitary Tumors

OBJECTIVE

To attempt to determine clinical or hormonal characteristics that could help distinguish benign idiopathic low testosterone (ILT) from pituitary tumor.

METHODS

On retrospective review of medical records of patients encountered by Johns Hopkins endocrine staff between 1985 and July 1995, 64 patients who fulfilled our enrollment criteria--27 men with ILT and 37 patients with imaging-proven pituitary tumor--were identified. Men 21 years of age or older needed to have had serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin levels measured before hormonal replacement therapy or pituitary tumor extirpation (or both) and a high-quality imaging scan (computed tomography or magnetic resonance imaging) done and interpreted by the Johns Hopkins radiology staff.

RESULTS

In comparison with men who had ILT, men with pituitary tumors had similar serum testosterone levels and significantly higher serum levels of LH, FSH, and prolactin. In addition, significantly more men with pituitary tumors had visual field abnormalities, headaches, and symptoms of hypothyroidism in comparison with the men with ILT. In contrast, the group with ILT complained significantly more of impotence, erectile dysfunction, and depression than did the group with pituitary tumors. The age at initial assessment was comparable in both study groups.

CONCLUSION

Although age at initial manifestation did not predict the presence of pituitary tumor, the group of men with tumors were more likely than those with ILT to have serum testosterone levels <150 ng/dL, higher serum gonadotropin and prolactin levels, and visual field abnormalities and less likely to have sexual dysfunction. Therefore, on the basis of our data, we recommend that men with these findings should be referred for a magnetic resonance image to exclude the presence of a tumor.

Craniofacial morphology in patients with Kallmann's syndrome with and without cleft lip and palate

OBJECTIVE

Kallmann's syndrome is characterized by the association of hypogonadotropic hypogonadism and anosmia or hyposmia. The principal endocrine defect of hypogonadotropic hypogonadism is a failure to secrete luteinizing hormone-releasing hormone (LHRH), resulting in underdevelopment of the pituitary gonadotropes and an inability to synthesize and release luteinizing hormone and follicle-stimulating hormone. The purpose of the present investigation was to describe the dentition and the craniofacial morphology in patients diagnosed with Kallmann's syndrome.

DESIGN

The sample consisted of 11 patients, 2 of whom also had bilateral cleft lip and palate. Radiographic investigations, including cephalometry, were performed. Comparisons were made to normal individuals and to cleft lip individuals without Kallmann's syndrome.

RESULTS

Dentition: tooth agenesis occurred more frequently in patients with Kallmann's syndrome. Craniofacial morphology: Increased mandibular inclination and mandibular angulation were seen in Kallmann patients. When clefting also occurred, extreme retrognathism of both maxilla and mandible was seen, a deviation which seemingly worsened during growth. The anterior cranial base and the sphenoid bone showed an altered morphology in one of the patients with Kallman's syndrome.

CONCLUSIONS

An early diagnosis of Kallmann's syndrome is very important because the prognosis for endocrine treatment thereby improves, and therefore, it is recommended that the sense of smell be evaluated in patients with the craniofacial morphology described.

Current concepts in the pathophysiology of testicular undescent

At present, we believe that descent of the testes within the human is a complex event mediated by both hormonal and mechanical factors. We hypothesize that descent of the testes occurs as a result of the secretion of an androgen-independent factor from a normal testis (descendin). This paracrine factor is responsible for the rapid proliferation (outgrowth) of the ipsilateral gubernaculum. The development of the gubernaculum results in creating a dilated inguinal canal, the width of which matches the testicular width. Descent of the testes through the inguinal canal is an interplay between abdominal pressure, a patent processus vaginalis, and androgen-induced gubernacular regression. We hypothesize that androgens (under control of an intact hypothalamic pituitary axis) alter the viscoelastic properties of the gubernaculum, reducing the turgidity of the gubernaculum and allowing intra-abdominal pressure to push the testis into the scrotum. Cryptorchidism can therefore result when any one or more of the involved factors malfunction.

The role of TRH-stimulated prolactin responses in distinguishing gonadotropin deficiency from constitutional delayed puberty

LHRH and TRH tests were performed in 16 boys age 14.5-18.5 years with constitutional delayed puberty (CDP); 9 idiopathic hypogonadotropic hypogonadism (IHH) males, age 15.0-22.0 years; and 7 control subjects age 14.5-19.5 years. The responses of FSH and LH to LHRH stimulation overlapped so that it was difficult to differentiate IHH from CDP. Some patients with IHH had normal gonadotropin responses. Basal PRL levels were in the normal range in control, IHH, and CDP patients. We found a 6 to 25 times increment or a response of more than 22 ng/ml (normal response) with respect to basal levels in the control group. In the CDP group, we found 2 to 19 fold increments in basal PRL levels after TRH stimulation and the maximum response was more than 22 ng/ml in all the patients. In the IHH group, the increment in basal PRL levels was 2-9 times more after the TRH test and the maximum PRL response was more than 22 ng/ml in 6 of the 9 patients. Although the mean peak responses of PRL to TRH were significantly lower in the IHH group compared to CDP and controls (p < 0.001), the mean peak individual responses in all groups were in the normal range (minimum 2-fold increment) and the responses were more than 22 ng/ml in all cases except 3 of 9 patients in the IHH group. We conclude that PRL response to TRH may help in differentiating CDP from IHH if a "cut off" response level of 22 ng/ml is used.

Fertility after cryptorchidism: a comparative analysis of early orchidopexy with and without concomitant hormonal therapy in the young male rat

Infertility is common in patients with a history of bilateral cryptorchidism, even after successful prepubertal orchidopexy. Recent data suggest that this defect may be partially due to the existence of hormonal abnormalities in some forms of cryptorchidism. To analyze any potential benefit of hormonal therapy, we have evaluated the immediate and long-term effects of chronic hormonal therapy administered following surgical correction of cryptorchidism. First, using young male rats, we examined the effects of chronic human chorionic gonadotropin (HCG) and a luteinizing hormone-releasing hormone agonist (LHRH-A), alone or combined, on acute pituitary-gonadal axis responsiveness to LHRH administration. High doses of HCG and/or LHRH-A induced deleterious effects on the pituitary-testicular axis in terms of suppression of response to LHRH. Therefore, treatment with a low dose of HCG (50 U/kg/day) for 14 days was used, since it produced a significant increase in intratesticular testosterone (ITT). Second, we tested this hormonal regimen in a cryptorchid rat model. Bilateral cryptorchidism was produced by gubernaculum resection at 14 days of age. Early orchidopexy was performed at age 30 days, and HCG therapy was given from 31 to 44 days of age. Follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) levels were determined before and immediately after hormonal therapy, and at sacrifice. Animals were sacrificed at 61 days of age for determination of serum and testicular hormone levels, accessory sex organ weights and testis histology. Five or six animals from each group were retained for breeding studies at the age of 90 days. Hormonal alterations noted immediately following treatment of cryptorchid animals with HCG are not lasting. The data reveal that the fertility defect in bilateral cryptorchidism is partially prevented by early orchidopexy and that adjunctive hormonal therapy is probably of little additional benefit.

The fetal rat gubernaculum contains higher levels of androgen receptor than does the postnatal gubernaculum

The androgen receptor of the rat gubernaculum was measured by a sensitive immunoblotting technique from day 19 of fetal development to day 20 of postnatal development. In relative terms (densitometric units/microgram. protein), it was found that the amount of the gubernacular androgen receptor decreased dramatically from fetal to postnatal development, coincident with the transition of the gubernaculum from a tissue primarily composed of undifferentiated mesenchymal cells in the fetus to a tissue that is primarily made up of muscle during postnatal development. We conclude that the undifferentiated mesenchyme of the fetal gubernaculum is a primary target of androgen action.

Audiological, vestibular and radiological abnormalities in Kallman's syndrome

Kallman's syndrome is a multifaceted congenital disorder with predominantly endocrine abnormalities. We have characterized the associated mixed hearing loss and identified consistent radiological evidence of abnormal temporal bone anatomy. Abnormal labyrinthine morphology is accompanied by a complete absence of response to vestibular stimulation with caloric or rotational chair testing. The endocrine abnormalities are correctable and Kallman's syndrome is a diagnosis worthy of consideration when assessing children with congenital hearing loss.

Subcutaneous gonadotropin therapy in male patients with hypogonadotropic hypogonadism

OBJECTIVE

The response to subcutaneous (SC) gonadotropin replacement therapy, using human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) or hCG alone, was evaluated in male hypothalamic hypogonadism.

DESIGN

Sixteen patients with hypothalamic hypogonadism were treated with gonadotropins for induction of puberty and normalization of spermatogenesis. The results were analyzed retrospectively.

SETTING

The study was carried out in a clinical endocrinology department providing tertiary care and in private practices of endocrinology.

PATIENTS

Eight patients with idiopathic hypogonadotropic hypogonadism and eight patients with Kallmann's syndrome in prepubertal or early pubertal stages.

INTERVENTIONS

Human chorionic gonadotropin and hMG were administered SC in individual dosages.

MAIN OUTCOME MEASURES

Increase of serum testosterone (T), testicular volume, semen volume, and sperm count were evaluated.

RESULTS

Normalization of serum T and complete sexual maturation was achieved in all patients. Spermatogenesis was induced in all but two patients. Seven patients showed normal findings in semen volume and sperm count, and two patients had semen quality close to normal. In five patients sperm count remained less than 10 x 10(6)/mL.

CONCLUSIONS

The results obtained by SC gonadotropin replacement prove this mode of administration to be effective in stimulating steroidogenesis and spermatogenesis in hypogonadotropic males.

Achievement of spermatogenesis and genital tract maturation in hypogonadotropic hypogonadic subjects during long term treatment with gonadotropins or LHRH

15 subjects with Hypogonadotropic Hypogonadism (HH) were treated with either gonadotropins (13 cases) or pulsatile subcutaneous Luteinizing Hormone Releasing Hormone (LHRH) (2 cases) for up to 42 months, to study the effects of therapy step by step. The following results were obtained: (A) In postpubertal HH (5 cases = Group A), therapy brought about onset of spermatogenesis within 3 months and its normalization within 6 months. In HH of prepubertal onset (10 cases = Group B), spermatogenesis started within 9 to 21 months and became normal in only 3 cases after at least 18 months. The best sperm counts were obtained in Group A in the third month of treatment (41.75 +/- 43.68 mil./ml) and in Group B in the 36th month (14.87 +/- 17.06 mil./ml). Sperm motility was normal in the majority of the cases in Group A from the beginning but did not become normal in Group B. (B) Seminal fructose and zinc were normal from the beginning of therapy in 66% of the cases in both groups. Zinc became normal in 100% within 3 months in Group A, in Group B within 18. Carnitine was normal in 50% of cases in both groups, contemporaneous with sperm appearance. Transferrin was normal in Group A after appearance of spermatozoa, but in Group B never became normal. (C) We hypothesize that the recovery of fertility passes through the following stages: (1) Functional recovery of Leydig cells, followed by seminal vesicles and prostate. (2) Recovery of epididymal function, which probably implies beginning of the tubular function. Recovery of Sertoli cell function occurs with more difficulty.

Hormonal responses in pubertal males to pulsatile gonadotropin releasing hormone (GnRH) administration

Twenty-two boys (9 with delayed puberty and 13 with short stature) ages 12.3 - 17.8 yr, and 10 adult males with idiopathic hypogonadotropic hypogonadism (ages 17.3 - 41.1 yr) have been studied following pulsatile, sc GnRH therapy (240 ng/kg/pulse) over 6 days. Mean pre- and post-therapy LH and FSH concentrations were estimated by 15 min blood sampling over 3-h periods immediately before and at the end of the treatment period. There were significant correlations between the mean pre- and posttreatment LH and FSH concentrations (r = 0.82, p less than 0.001 and r = 0.51, p less than 0.02, respectively) for the 2 groups of peripubertal boys when assessed together. Nine of the 10 adults with hypogonadism showed proportionately greater gonadotropin increments following pulsatile therapy when compared with the peripubertal boys. Standard bolus GnRH tests (100 micrograms iv) did not differentiate between the three groups of patients before pulsatile GnRH therapy. Bolus GnRH tests could predict the subsequent response to pulsatile therapy in the peripubertal boys only. There was no significant change in LH increments following the GnRH bolus tests in either group, after pulsatile GnRH administration (p greater than 0.1). Early response to pulsatile GnRH administration is dependent upon the maturity of the hypothalamic-pituitary-testicular axis in males with delayed puberty or short stature. Patients with hypogonadotropic hypogonadism do not show this relationship.

Isolated gonadotropin deficiency in boys: clinical characteristics and growth

Analysis of the clinical findings and growth in 20 boys with isolated gonadotropin deficiency revealed a heterogeneous group of physical abnormalities. Ten of these patients were hyposmic or anosmic (Kallmann syndrome). Abnormalities found in our patients included undescended testes, gynecomastia, and ocular or skeletal anomalies. Regardless of the presence of hyposmia, patients without testicular enlargement (less than 2 cm3), had serum luteinizing hormone (LH) responses to luteinizing hormone-releasing factor (LRF) that were the same as in prepubertal boys. By contrast, five boys with testicular enlargement (greater than 2 cm3), some of whom had hyposmia, had a greater serum LH response to LRF than did prepubertal boys. Adrenarche was moderately delayed; although all boys initially had normal serum levels of dehydroepiandrosterone-sulfate, four boys eventually developed elevated serum levels. Bone ages were delayed compared with chronologic age in boys who had the condition after 15 years of age. The rate of linear growth was normal, and final adult heights were normal with testosterone therapy, although linear growth continued longer in these boys than in boys with normal pubertal progression. Although none of the patients was obese at the time of diagnosis, three patients developed obesity after initiation of testosterone therapy.

Estimating frequency of Kallmann syndrome among hypogonadic and among anosmic patients

The frequency of Kallmann syndrome (hypogonadotropic hypogonadism and anosmia, HHA) was estimated in patients presenting with hypogonadism and patients with anosmia. Of 791 hypogonadal males 19 had HHA. The frequency of HHA was about 1:25 (n = 8/189) in outpatients questioned about their sense of smell, about 1:50 (n = 11/579) in patients whose blood samples were sent to us for chromosome analysis, and about 1:30 (n = 19/605) in males with hypogonadism and 46,XY chromosomes. The relation of patients with HHA to those with Klinefelter syndrome was 1:10 (n = 19/186). From 24 patients presenting with anosmia we found 1 hitherto undiagnosed case of HHA. The mean age at diagnosis was 24.8 and 24.9 years in our cases and cases from literature, respectively. These data provide evidence that Kallmann syndrome is not infrequent and that most patients remain undiagnosed until the third decade of life. Earlier diagnosis is emphasized by questioning each hypogonadal patient about his sense of smell because therapeutic success seems to be age dependent.

Hormonal regulation of testicular descent

The involvement of testosterone in testicular descent and the mechanism of testicular descent were analyzed and discussed.

Abnormal prolactin secretion in prepubertal boys with hypogonadotrophic hypogonadism--possible involvement in regulation of testicular steroidogenesis

The interrelationships of prolactin (Prl), gonadotrophins and testicular steroids were studied in prepuberty in 6 boys with isolated hypogonadotrophic hypogonadism (HH) and 7 boys with incomplete testicular descent (who served as controls). The boys with HH had higher basal serum levels of Prl (P less than 0.001) and LH (P less than 0.05) than the controls, but lower Prl (P less than 0.001) and LH (P less than 0.05) responses after metoclopramide + LHRH and lower testosterone responses after hCG. The peak responses of Prl after metoclopramide + LHRH and of testosterone after hCG correlated strongly in the patients as a whole (r = 0.87, P less than 0.001). These observations indicate that, as well as in the gonadotrophins, changes occur in HH in prepuberty in the synthesis and/or release of Prl. The findings also raise the possibility that Prl may play a role in the regulation of testosterone synthesis by the prepubertal testis.

Gonadotropin-releasing hormone test and human chorionic gonadotropin test in the diagnosis of gonadotropin deficiency in prepubertal boys

The discriminatory power of a gonadotropin-releasing hormone test and a human chorionic gonadotropin test in diagnosing gonadotropin deficiency was studied in 23 prepubertal boys with hypogonadotropic hypogonadism (HH). The boys were originally referred because of genital hypoplasia, delayed sexual maturation, or suspicion of HH. The diagnosis of HH was established clinically, in most cases after follow-up of several years. The results were compared with those of a reference group consisting of 44 prepubertal boys with incomplete testicular descent. Post-hCG serum testosterone level was the most sensitive discriminating variable, and was subnormal in 11 of 12 boys with HH (in one of 16 in the reference group). Post-GnRH serum LH concentration was the second most sensitive, and was subnormal in 15 of 23 boys with HH (two of the reference group). Our data indicate that post-hCG testosterone levels are of greater value than post-GnRH gonadotropin levels in the diagnosis of HH in prepubertal boys.

Testicular steroidogenic response to human chorionic gonadotropin of fifteen male transsexuals on chronic estrogen treatment

Fifteen transsexuals were prepared for surgery with estrogen treatment. The response to human chorionic gonadotropin (hCG) in the untreated state was similar to that of normal subjects when testosterone (T), estradiol-17 beta (E2), 17 alpha-hydroxyprogesterone (17 alpha-OHP), progesterone (P), 4-androstenedione (delta 4A), and dehydroepiandrosterone (DHA) were used as indices. Following estrogen therapy, plasma T, 17 alpha-OHP, and DHA levels were markedly reduced whereas delta 4A and P were not. In spite of the suppressive effects of estrogen, a good response to hCG was noted in such subjects in plasma levels of T, 17 alpha-OHP, and, to a lesser extent, delta 4A even after estrogen administration for 24 months. The high rates of 17 alpha-OHP to T induced by estrogen treatment is restored to normal by the administration of hCG.

Familial spastic paraplegia with Kallmann's syndrome

A sibship is reported in which two males have spastic paraparesis and Kallmann's syndrome (hypogonadotrophic hypogonadism and anosmia). One of the brothers also is color blind. The association of familial spastic paraplegia and Kallmann's syndrome has not been described previously.

Familial idiopathic gonadotropin deficiency: a hypothalamic form of hypogonadism

To date, familial idiopathic gonadotropin deficiency (FIGD) has not been delineated as either a hypothalamic or a pituitary form of hypogonadism. Leydig cell sensitivity to human chorionic gonadotropin (HCG) has also been suggested as subnormal in FIGD. Also, in a few previously reported families the Kallmann syndrome was not clearly ruled out. Data herewith reported on three sibs with FIGD supported the following conclusions: 1) FIGD is due to insufficient hypothalamic luteinizing hormone-releasing hormone (LRH) secretion, 2) the sensitivity of Leydig cells to HCG is normal, 3) LRH treatment may be helpful in these patients, 4) an associated hypothalamic-pituitary-prolactin (PRL) dysfunction may also be present, and 5) FIGD and the Kallmann syndrome are different entities having a similar pathophysiology but different cause and overall clinical picture.

The role of thyrotrophin releasing hormone in the diagnosis of isolated gonadotrophin deficiency

We studied the response of PRL and TSH to thyrotrophin-releasing hormone (TRH) in 15 boys with delayed adolescence and 6 male subjects with isolated gonadotrophin deficiency (IGD). TRH tests were repeated in the IGD subjects during and 1 month following hCG treatment. Male IGD subjects showed a significantly decreased basal and TRH induced PRL response compared to male controls and subjects with delayed adolescence. Human chorionic gonadotrophin (HCG) treatment of male IGD subjects restored basal and stimulated PRL levels to the range of normal controls. This was, presumably, an estrogenic effect since non aromatizable androgens did not increase the PRL response; moreover, the antioestrogen, clomiphene, decreased the PRL response when given with HCG. The TSH response to TRH in delayed adolescents was increased as compared to adult male controls and IGD subjects and was similar to adult female controls. HCG treatment of IGD subjects had no effect on basal nor peak TSH levels, although ethinyl oestradiol did increase the TSH response in two IGD subjects. These studies show that the PRL and TSH responses to TRH may differentiate delayed adolescence from IGD. The increased TSH response to TRH in delayed adolescence as compared to adult males, is a manifestation of an enhanced oestrogen effect in these patients. The abnormal PRL dynamics in IGD is a consequence of estrogen deficiency.

The syndrome of anosmia with hypogonadotropic hypogonadism: a genetic study of 18 new families and a review

Among 18 NIH probands with anosmia and hypogonadotropic hypogonadism (AHH), seven had affected relatives and three had consanguineous parents. Both sexes were equally affected and parents were phenotypically normal. Parental age was not increased. Cleft lip and palate occurred in both eugonadal and hypogonadal persons, a previously reported association that may represent variable expression of AHH. Diabetes mellitus, usually insulin-dependent, was frequent in probands and their families. Other common traits included obesity, cryptorchidism, and hearing loss. All probands were chromosomally normal. The frequency of some dermatoglyphic traits of probands differed from normal, but no trait was unique to AHH. Segregation analysis of our proband sibships was consistent with a hypothesis of autosomal-recessive inheritance with variable expression. However, genetic heterogeneity was apparent when previous reports of familial AHH were surveyed. An X-linked or male sex-limited autosomal-dominant form with unilateral renal agenesis, mental retardation, and hypotelorism has been observed. The infrequent reports of direct male-to-male transmission limit characterization of an autosomal-dominant form of AHH. Our phenotypic analysis suggests that the traits of mental retardation, renal anomalies, hypotelorism, diabetes, and hearing loss may help to distinguish various forms of AHH, whereas cryptorchidism, clefts, and obesity appear in several types of families. At present, genetic counseling is dependent upon establishing inheritance pattern after examination for the known associated anomalies.

Hypogonadotrophic hypogonadism resistant to hCG and responsive to LHRH: report of a case

The treatment of hypogonadotrophic hypogonadism with gonadotrophin releasing hormone (LHRH) has proved difficult in the past because of a progressive decline in the pituitary gonadotrophin response. These early studies generally used large relatively infrequent doses of natural LHRH (Davies et al., 1977) or analogues with a prolonged action (Smith et al., 1979). Recently, several reports have indicated that the lack of gonadotrophin response to LHRH can be overcome by frequent administration of low doses of natural LHRH in a pulsatile fashion (Belchetz et al., 1978; Crowley et al., 1980; Jacobson et al., 1979; Schoemaker et al., 1981; Valk et al., 1980). However, it is not known whether those patients with hypogonadotrophic hypogonadism who fail to respond to human chorionic gonadotrophin (hCG) (Bardin et al., 1969) are capable of responding to LHRH. In this case report of a patient with hypogonadotrophic hypogonadism who was resistant to prolonged hCG therapy, normal pituitary gonadotrophin and testosterone responses were obtained following pulsatile LHRH administration. The sperm count rose to 11 X 10(6)/ml. His wife became pregnant and was delivered of a normal healthy female infant after an uneventful pregnancy.

The effect of growth hormone on the Leydig cell response to chorionic gonadotrophin in boys with hypopituitarism

Eleven boys with growth hormone (hGH) deficiency received human chorionic gonadotrophin (hCG) stimulation tests for the assessment of Leydig cell function before, during, and after 1 year of treatment with somatotrophin. Two patients entered puberty during the course of the study protocol. Analysis of the data in nine prepubertal boys revealed an augmentation of testosterone (T) responses to hCG in the presence of hGH. In six of these individuals in whom dihydrotestosterone (DHT) was determined, a similar augmentation in responsiveness of this steroid was found in the presence of hGH. Three prepubertal boys exhibited poor T responses to the basal hCG test with only partial improvement following hGH. In man growth hormone may be an important permissive factor in Leydig cell activity during periods of changing testicular function such as occur in utero or during puberty.

Effect of D-leucine-6-luteinizing hormone-releasing hormone ethylamide in patients with hypogonadotropic hypogonadism with anosmia

Four men with hypogonadotropic hypogonadism and anosmia were tested with acute intravenous injections of luteinizing hormone-releasing hormone (LH-RH) and D-leucine-6-LH-RH-ethylamide (D-L eu-6-LH-RH-EA) with a 1-week interval. Each patient was then treated with this drug for 60 days and tested again after this period with an intravenous injection of D-L eu-6-LH-RH-EA. The administration of LH-RH resulted in a significant increase in the LH level in only one patient and in follicle-stimulating hormone (FSH) and testosterone increases in none. The analog D-Leu-6-LH-RH-EA resulted in significant increases in LH levels in two patients, in FSH levels in three, and in testosterone levels in one. Results obtained after treatment were closely similar to those observed before treatment. Clinical improvement in terms of increased libido, erection, pubic hair growth, and testicular size was observed. D-Leu-6-LH-RH-EA could be useful in the treatment of patients with hypogonadotropic hypogonadism, a possibility deserving further studies.

Electron microscopic studies of testes in Kallman syndrome

A patient with Kallman syndrome is presented emphasizing the urologic aspects of this unusual disorder. Testes biopsy at the time of orchiopexy demonstrated infantile testes with interstitial fibrosis and a diminished Leydig and Sertoli cell population. The electron micrograph confirmed type B Sertoli cells. The implications of these findings are discussed and details of treatment given.