Mutation analyses in pedigrees and sporadic cases of ethnic Han Chinese Kallmann syndrome patients

Kallmann syndrome, a form of idiopathic hypogonadotropic hypogonadism, is characterized by developmental abnormalities of the reproductive system and abnormal olfaction. Despite association of certain genes with idiopathic hypogonadotropic hypogonadism, the genetic inheritance and expression are complex and incompletely known. In the present study, seven Kallmann syndrome pedigrees in an ethnic Han Chinese population were screened for genetic mutations. The exons and intron–exon boundaries of 19 idiopathic hypogonadotropic hypogonadism (idiopathic hypogonadotropic hypogonadism)-related genes in seven Chinese Kallmann syndrome pedigrees were sequenced. Detected mutations were also tested in 70 sporadic Kallmann syndrome cases and 200 Chinese healthy controls. In pedigrees 1, 2, and 7, the secondary sex characteristics were poorly developed and the patients’ sense of smell was severely or completely lost. We detected a genetic mutation in five of the seven pedigrees: homozygous KAL1 p.R191ter (pedigree 1); homozygous KAL1 p.C13ter (pedigree 2; a novel mutation); heterozygous FGFR1 p.R250W (pedigree 3); and homozygous PROKR2 p.Y113H (pedigrees 4 and 5). No genetic change of the assayed genes was detected in pedigrees 6 and 7. Among the 70 sporadic cases, we detected one homozygous and one heterozygous PROKR2 p.Y113H mutation. This mutation was also detected heterozygously in 2/200 normal controls and its pathogenicity is likely questionable. The genetics and genotype–phenotype relationships in Kallmann syndrome are complicated. Classical monogenic inheritance does not explain the full range of genetic inheritance of Kallmann syndrome patients. Because of stochastic nature of genetic mutations, exome analyses of Kallmann syndrome patients may provide novel insights.     

High frequency of association of rheumatic/autoimmune diseases and untreated male hypogonadism with severe testicular dysfunction

Our goal in the present work was to determine whether male patients with untreated hypogonadism have an increased risk of developing rheumatic/autoimmune disease (RAD), and, if so, whether there is a relation to the type of hypogonadism. We carried out neuroendocrine, genetic, and rheumatologic investigations in 13 such patients and 10 healthy male 46,XY normogonadic control subjects. Age and body mass index were similar in the two groups. Nine of the 13 patients had hypergonadotropic hypogonadism (five of whom had Klinefelter's syndrome [karyotype 47,XXY]) and 4 of the 13 had hypogonadotropic hypogonadism (46,XY). Of these last four, two had Kallmann's syndrome and two had idiopathic cryptorchidism.     

Acromegaly Presenting as Erectile Dysfunction: Case Reports and Review of the Literature

Erectile dysfunction (ED) is a common yet complex condition. The authors report two cases of acromegaly presenting with ED and hypogonadotropic hypogonadism. Surgical cure of the acromegaly was associated with either an improvement or resolution of hypogonadotropic hypogonadism-associated ED. Active acromegaly should be considered in the differential diagnosis of ED presenting with supporting clinical features, particularly hypogonadotropic hypogonadism.Key words: Erectile dysfunction, Endocrine dysfunction, Endocrinology, Acromegaly, Growth hormoneErectile dysfunction (ED), defined as an inability to obtain or maintain penile erection sufficient for sexual activity, is a common complaint with often complex etiology. Prevalence increases with age, ranging from 1% to 10% of men under age 40, 20% to 40% of men age 60 to 69 years, and 50% to 100% of men in their 70s and 80s.¹ ED can be a symptom of numerous underlying conditions, and guidelines on management of ED outline assessment for reversible hormonal causes such as hypogonadism, thyroid dysfunction, and hyperprolactinemia.^2,3 Although hypogonadism and hyperprolactinemia have been shown to be associated with acromegaly,⁴ the link between acromegaly and ED has not been widely reported.^5,6 We describe two cases of acromegaly with ED as the presenting feature and review the outpatient diagnosis of acromegaly.     

Pulsatile gonadotropin-releasing hormone treatment of men with idiopathic hypogonadotropic hypogonadism

OBJECTIVES/METHODS: To induce testicular growth and spermatogenesis, 11 patients with idiopathic hypogonadotropic hypogonadism were treated with long-term subcutaneous pulsatile gonadotropin-releasing hormone (GnRH) administration. Three patients had a history of undescended testes. Patients who did not respond to therapy with a sufficient increase in serum testosterone or spermatogenesis were offered additional injections with hCG or, after discontinuation of GnRH, either combined therapy with hCG and hMG or recombinant FSH. RESULTS: During treatment testicular volume and serum levels of FSH, LH and testosterone increased. Semen analysis revealed the presence of spermatogenesis in 9 of the 11 patients (8 on GnRH alone and in 1 when hCG/hMG was subsequently instituted), and 7 pregnancies have resulted thus far. CONCLUSION: Pulsatile GnRH therapy is a well-tolerated and effective therapy for the induction of spermatogenesis in some men with idiopathic hypogonadotropic hypogonadism. It appears that a significant fraction of them should be treated for a minimum of 1-2 years to maximize testicular growth and achieve spermatogenesis. Cryptorchidism was a negative prognostic factor.     

Molecular pathogenesis of lipoid adrenal hyperplasia and adrenal hypoplasia congenita

Congenital lipoid adrenal hyperplasia (lipoid CAH) is the most severe form of CAH in which the synthesis of all gonadal and adrenal cortical steroids is markedly impaired. Lipoid CAH may be caused by the defect in either the steroidogenic acute regulatory (StAR) protein or the P450scc. More than 34 different mutations in StAR gene have been identified. Clinically, most of the patients manifest adrenal insufficiency from 1 day to 2 months of age, but some patient show delayed onset of adrenal insufficiency. Affected 46, XY subjects do not show pubertal development, whereas affected 46, XX subjects undergo spontaneous feminization, breast development and cyclical vaginal bleeding at the usual age of puberty.

X-linked adrenal hypoplasia congenital (AHC) is a rare congenital adrenal disorder characterized by severe adrenal insufficiency and hypogonadotropic hypogonadism. More than 80 different several intragenic mutations of DAX-1 have been identified. The failure of pubertal development may be caused by either abnormal hypothalamic or pituitary regulation of gonadotropin secretion. In addition, although the testicular steroidogenesis is largely intact, the functional maturity of Sertoli cells and also spermatogenesis are impaired. The type of mutation does not predict clinical phenotype. Thus, unified mechanism how DAX-1 gene defect gives rise to adrenal insufficiency, hypothalamic/pituitary hypogonadism and impaired spermatogenesis remains established.     

A protein family immunorelated to a sperm-binding protein and its regulation in human semen

In human seminal plasma a family of proteins that is immunologically related to the RSV-IV protein secreted under androgen control from the epithelium of the rat seminal vesicles was detected by a radioimmunoassay. Evidence for the origin of these antigens from human seminal vesicle is presented. Quantitative measurements of this family of proteins were performed in men with low levels of serum testosterone (idiopathic hypogonadotropic hypogonadism) and in individuals having serum testosterone in the normal range of values but carrying sex chromosome aberrations (Klinefelter's syndrome). In the first case we have found a marked decrease in the total amount of the RSV-IV-related proteins. An increase of about 40% in the total amount of these antigens was obtained in these subjects by gonadotropin treatment. A decreased amount of these proteins was also detected in the subjects affected by Klinefelter's syndrome. The possibility that some factor(s) under genetic control is involved, in addition to testosterone, in the regulation of this family of proteins is discussed.     

Hypogonadotropic hypogonadism in women

This article presents the role of the hypothalamus in reproduction, the definition of hypogonadotropic hypogonadism (HH), and the causes of acquired and syndromic HH and idiopathic HH (IHH). The authors present a short review of major causes of acquired HH, but most of the causes of IHH will not be discussed because they do not fall within the scope of the article. More attention is devoted to idiopathic HH, especially the genetic basis of IHH. Also presented in the article are clinical criteria of CHARGE syndrome. Later, the article discusses the clinical presentation, establishing the diagnosis, and management of IHH. The article ends with a brief overview of nutritional hypothalamic dysfunction and athletic amenorrhea.     

Comparison between the meiotic activities in the male with hypogonadotropic hypogonadism and in the human fetal ovocytes

In the testicles of males with postpuberal hypogonadotropic hypogonadism, we have detected a preleptotene phase similar to that described in the human ovary. The two characteristic stages of this phase, contraction and despiralization, were noted. In this paper the origin and the significance of preleptotene in relation to the hormonal levels are discussed.     

Prevalence of Hypogonadism in Patients with Type 2 Diabetes Mellitus in an Asian Indian Study Group

ObjectiveTo determine the prevalence of hypogonadism in Asian Indian patients with type 2 diabetes mellitus (T2DM) and to correlate it with components of the metabolic syndrome and microvascular complications of T2DM.MethodsOne hundred consecutive male patients with T2DM between 25 and 50 years of age and 50 age-matched healthy adults without diabetes underwent assessment. Calculated free testosterone was derived by using serum total testosterone and sex hormone-binding globulin. Those patients with 2 calculated free testosterone values less than 64.8 pg/mL were diagnosed as having hypogonadism.ResultsOf the 100 patients with T2DM, 15 (15%) were found to have hypogonadism—7 of 29 (24%) between 31 and 40 years of age and 8 of 67 (12%) between 41 and 50 years old. None of the 4 patients between 25 and 30 years old had hypogonadism. Eleven patients (73%) had hypogonadotropic hypogonadism, and 4 (27%) had hypergonadotropic hypogonadism. Among the control subjects, the prevalence of hypogonadism was 10%. In comparison with Western data, we found a higher prevalence of hypogonadism in patients with T2DM, especially in those in the 4th decade of life. The prevalence of hypogonadism was higher in obese patients, although it did not reach statistical significance. No statistically significant correlation was observed between hypogonadism and age, duration of diabetes, glycemic control, androgen deficiency symptoms, or microvascular complications.ConclusionThe prevalence of hypogonadism was higher in the patients with diabetes than in the control subjects, although the difference did not reach statistical significance. There was no correlation of hypogonadism with components of the metabolic syndrome or microvascular complications of diabetes mellitus. (Endocr Pract. 2009;15:513-520)     

Phenotype of patients with gynecomastia

INTRODUCTION: Gynecomastia, a benign enlargement of the breast glandular tissue in men. The aim of the study was to evaluate the phenotype of patients with gynecomastia, in particular antropometric assessment, breast ultrasound examination and hormonal testing, as well as to estimate possible causes of gynecomastia in studied population. MATERIAL AND METHODS: Two hundred-twenty men were enrolled in the study: 126 patients with gynecomastia and 94 healthy volunteers as a control group. Detailed medical examination, breast ultrasound and hormonal assays for T, E2, LH, FSH, SHBG, S-DHEA, PRL and TSH were performed. Calculation of free testosterone concentration was done. RESULTS: The results of clinical and hormonal evaluation enabled to divide the cases into three groups: patients with idiopathic gynecomastia (58 subjects, 46%), with hypogonadism (34 subjects, 27%) and drug-induced or associated with other disorders gynecomastia (34 subjects, 27%). We found that men with gynecomastia, particularly associated with hypogonadism, had significantly higher BMI compared with control group. Ultrasound examination revealed the positive correlation between breast tissue volume and BMI, duration of gynecomastia and estradiol level, while negative correlation with testosterone level. We demonstrated significant differences in LH, T, SHBG, fT and S-DHEA levels between cases and controls. There were no differences in PRL, FSH and TSH levels among groups. Significant elevation of SHBG concentration in all groups of patients, including idiopathic gynecomastia cases, compared with controls, was remarkable. CONCLUSION: Clinical evaluation and hormonal profile can help to classify patient with gynecomastia into one of three groups: idiopathic gynecomastia, associated with hypogonadism, and drug-induced or associated with other diseases. Idiopathic gynecomastia - of unknown etiology is diagnosed in almost half of all cases (46%). We showed that apart from well known hormonal disturbances leading to gynecomastia, like hypogonadism or hyperestrogenism, also subtle hormonal alterations, such as sex hormone binding globuline (SHBG) level elevation may contribute to breast enlargement.     

Small supernumerary marker chromosome (sSMC) derived from chromosome 22 in an infertile man with hypogonadotropic hypogonadism

We describe the first case of a supernumerary inv dup(22)(q11.1) in an infertile male with hypogonadotropic hypogonadism. This case supports the opinion that supernumerary inv dup(22)(q11.1) could play a role in male infertility. We suggest that the breakpoint in the region 22q11.1 and/or fourfold dosage of centromeric/pericentromeric sequences of the chromosome 22 may be the cause of hypogonadotropic hypogonadism resulting in impaired spermatogenesis and infertility in our patient.     

Induction of puberty in a patient with hypogonadotropic hypogonadism: effect of sequentially applied hCG and pulsatile GnRH administration

Pulsatile substitution with GnRH appears to be the therapy of choice in patients with Kallmann's syndrome, a well defined type of hypogonadotropic hypogonadism. We tried to simplify the treatment and to limit the subcutaneous GnRH therapy to the period absolutely necessary to induce spermatogenesis. Therefore we applied in sequence first hCG to stimulate testicular growth and second pulsatile GnRH application to induce spermatogenesis. We herein report that with this mode of therapy testicular growth from infantile to adult size and normal spermatogenesis could be achieved. We conclude that pulsatile GnRH application is a new effective therapy of hypogonadotropic hypogonadism which can be simplified considerably by pretreatment with hCG.     

Les hypogonadismes hypogonadotrophiques congénitaux masculins, quelles données récentes ?

Congenital hypogonadotropic hypogonadism (CHH) is a very heterogeneous group of disorders resulting from a deficiency of pituitary gonadotropin secretion that is related to defective migration of GnRH neurons or dysfunction of pituitary or hypothalamic system. Gonadotropin deficiency remains a rare cause of hypogonadism; its prevalence is not definitely established and is thought to be about 1/5,000. It is responsible for clinical symptoms that are related to low testosterone levels. The classification of CHH which was previously based on presence of or lack of anosmia has been enriched in the last two decades by the discovery of many genes involved. This allowed a better understanding of CHH and led to new approaches regarding genetic counselling.     

Deletion of Otx2 in GnRH neurons results in a mouse model of hypogonadotropic hypogonadism

GnRH is the central regulator of reproductive function responding to central nervous system cues to control gonadotropin synthesis and secretion. GnRH neurons originate in the olfactory placode and migrate to the forebrain, in which they are found in a scattered distribution. Congenital idiopathic hypogonadotropic hypogonadism (CIHH) has been associated with mutations or deletions in a number of genes that participate in the development of GnRH neurons and expression of GnRH. Despite the critical role of GnRH in mammalian reproduction, a comprehensive understanding of the developmental factors that are responsible for regulating the establishment of mature GnRH neurons and the expression of GnRH is lacking. orthodenticle homeobox 2 (OTX2), a homeodomain protein required for the formation of the forebrain, has been shown to be expressed in GnRH neurons, up-regulated during GnRH neuronal development, and responsible for increased GnRH promoter activity in GnRH neuronal cell lines. Interestingly, mutations in Otx2 have been associated with human hypogonadotropic hypogonadism, but the mechanism by which Otx2 mutations cause CIHH is unknown. Here we show that deletion of Otx2 in GnRH neurons results in a significant decrease in GnRH neurons in the hypothalamus, a delay in pubertal onset, abnormal estrous cyclicity, and infertility. Taken together, these data provide in vivo evidence that Otx2 is critical for GnRH expression and reproductive competence.     

Erythrocyte ferritin content in idiopathic haemochromatosis and alcoholic liver disease with iron overload.

The erythrocyte ferritin content was measured in patients with either idiopathic haemochromatosis or alcoholic liver disease and iron overload to define its value as a marker for an excess of tissue iron. The mean erythrocyte ferritin content in patients with untreated idiopathic haemochromatosis was increased 60-fold and fell with phlebotomy. After phlebotomy many patients had an increased red cell ferritin content despite normal serum ferritin concentrations. That this reflected persistent iron overload with inadequate phlebotomy was suggested by the higher serum iron concentrations, percentage transferrin saturation, and urinary excretion of iron after administration of desferrioxamine, together with a lower annual iron loss by phlebotomy in this group compared with patients with treated disease and normal red cell ferritin content. The mean erythrocyte ferritin content in patients with alcoholic liver disease and iron overload was increased only sevenfold, and the ratio of erythrocyte to serum ferritin clearly discriminated these patients from those with idiopathic haemochromatosis. The determination of erythrocyte ferritin content is a useful non-invasive test for diagnosing idiopathic haemochromatosis, monitoring the effect of phlebotomy in this disorder, and distinguishing patients with this disorder from those with alcoholic liver disease with iron overload.     

Normal sequence of the gonadotropin-releasing hormone gene in patients with idiopathic hypogonadotropic hypogonadism.

Idiopathic hypogonadotropic hypogonadism (IHH) results from absent or greatly diminished secretion of GnRH. Defects in the GnRH gene have been identified in an animal model of IHH and have been hypothesized as a possible basis for GnRH deficiency in humans. In this study, we used the polymerase chain reaction to clone and sequence the coding regions, promoter, and 3' untranslated tract of the GnRH genes from both alleles of four unrelated patients with IHH. One of the patients studied is a member of a kindred in which X-linked inheritance has been excluded by father-to-son transmission of the disease. No DNA sequence mutations were found. We conclude that most cases of IHH in humans do not involve mutations in the GnRH gene and are presumably caused by mutations at one or more other genetic loci that are required for normal function of GnRH-producing neurons.     

Lack of nocturnal prolactin increase in patients with hypogonadotropic hypogonadism

The circadian prolactin rhythm was studied in a group of 16 male adult volunteers: 10 healthy subjects and 6 patients affected by isolated hypogonadotropic hypogonadism (IHH). A significant nycto-hemeral prolactin rhythm (p = 0.0003, according to cosinor method) is detected in healthy subjects, but not in patients with IHH. In view of these results we may deem that the absence of nycto-hemeral variations of serum prolactin in subjects with IHH could be caused by failure of LH and FSH release.     

A novel heterozygous SOX2 mutation causing congenital bilateral anophthalmia,hypogonadotropic hypogonadism and growth hormone deficiency

Heterozygous de novo mutations in SOX2 have been reported in approximately 10–20% of patients with unilateral or bilateral anophthalmia or microphthalmia. An additional phenotype of hypopituitarism, with anterior pituitary hypoplasia and hypogonadotropic hypogonadism, has been reported in patients carrying SOX2 alterations. We report a novel heterozygous mutation in the SOX2 gene in a male affected with congenital bilateral anophthalmia, hypogonadotrophic hypogonadism and growth hormone deficiency. The mutation we describe is a cytosine deletion in position 905 (c905delC) which causes frameshift and an aberrant C-terminal domain. Our report highlights the fact that subjects affected with eye anomalies and harboring SOX2 mutations are at high risk for gonadotropin deficiency, which has important implications for their clinical management.     

Hypothalamic hypogonadism in congenital adrenal hypoplasia

Congenital adrenal hypoplasia (CAHP) in its X-linked form is associated with hypogonadotropic hypogonadism (HH). A 23 year old man with this disorder received substitution therapy with gluco- and mineralocorticoids starting one week after birth and, recently, pulsatile subcutaneous GnRH treatment via a miniature infusion pump with stepwise increasing doses from 50 to 200 ng/kg body weight/2 hours for a total of 394 days. Testosterone levels increased from prepubertal levels to 409 ng/dl after 2 weeks and to 626 ng/dl after 3 months of treatment. The results of pulsatile GnRH therapy in our patient prove the hypogonadotropic hypogonadism to be of hypothalamic origin. Pulsatile GnRH substitution is a successful therapeutic regimen in patients with CAHP leading to pituitary and gonadal maturation.