Gonadotrophin pulsatility in girls with the Turner syndrome: modulation by exogenous sex steroids

Hypogonadism in Pediatric Health: Adult Medicine Concepts Fail

The classical definition of hypogonadism, used in adult medicine, as gonadal failure resulting in deficient steroid and gamete production, and its classification into hypergonadotropic and hypogonadotropic refer to primary gonadal and hypothalamic-pituitary disorders respectively and may lead to under- or misdiagnosis in pediatrics. Indeed, in children with primary gonadal failure, gonadotropin levels may be within the reference range for age. Conversely, since gonadotropins and steroids are normally low during childhood, it may prove impossible to show the existence of a hypogonadotropic state before pubertal age. Anti-Müllerian hormone (AMH) and inhibin B arise as more adequate biomarkers to assess gonadal function and increase the possibility of making an earlier diagnosis of hypogonadism in children, which may positively impact on timely management.

Clinical Management of Congenital Hypogonadotropic Hypogonadism

The initiation and maintenance of reproductive capacity in humans is dependent on pulsatile secretion of the hypothalamic hormone GnRH. Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder that results from the failure of the normal episodic GnRH secretion, leading to delayed puberty and infertility. CHH can be associated with an absent sense of smell, also termed Kallmann syndrome, or with other anomalies. CHH is characterized by rich genetic heterogeneity, with mutations in >30 genes identified to date acting either alone or in combination. CHH can be challenging to diagnose, particularly in early adolescence where the clinical picture mirrors that of constitutional delay of growth and puberty. Timely diagnosis and treatment will induce puberty, leading to improved sexual, bone, metabolic, and psychological health. In most cases, patients require lifelong treatment, yet a notable portion of male patients (∼10% to 20%) exhibit a spontaneous recovery of their reproductive function. Finally, fertility can be induced with pulsatile GnRH treatment or gonadotropin regimens in most patients. In summary, this review is a comprehensive synthesis of the current literature available regarding the diagnosis, patient management, and genetic foundations of CHH relative to normal reproductive development.

Effect of oxandrolone therapy on adult height in Turner syndrome patients treated with growth hormone: a meta-analysis

Turner syndrome is a chromosomal abnormality in which there is complete or partial absence of the X chromosome. Turner syndrome effects 1 in every 2000 live births. Short stature is a cardinal feature of Turner Syndrome and the standard treatment is recombinant human growth hormone. When growth hormone is started at an early age a normal adult height can be achieved. With delayed diagnosis young women with Turner Syndrome may not reach a normal height. Adjuvant therapy with oxandrolone is used but there is no consensus on the optimal timing of treatment, the duration of treatment and the long term adverse effects of treatment. The objective of this review and meta-analysis is to examine the effect of oxandrolone on adult height in growth hormone treated Turner syndrome patients. Eligible trials were identified by a literature search using the terms: Turner syndrome, oxandrolone. The search was limited to English language randomized-controlled trials after 1980. Twenty-six articles were reviewed and four were included in the meta-analysis. A random effects model was used to calculate an effect size and confidence interval. The pooled effect size of 2.0759 (95 % CI 0.0988 to 4.0529) indicates that oxandrolone has a positive effect on adult height in Turner syndrome when combined with growth hormone therapy. In conclusion, the addition of oxandrolone to growth hormone therapy for treatment of short stature in Turner syndrome improves adult height. Further studies are warranted to investigate if there is a subset of Turner syndrome patients that would benefit most from growth hormone plus oxandrolone therapy, and to determine the optimal timing and duration of such therapy.

An isodicentric X chromosome with gonadal dysgenesis in a lady without prominent somatic features of Turner's syndrome. A case report

Isodicentric X chromosomes in general have phenotypes characteristic of the resultant X deletions. Gonadotropin levels in Turner's syndrome (TS) girls are high, but have a normal biphasic pattern. Here, we report a 21-year-old lady with primary amenorrhea. Clinical examination revealed a short neck but no other typical stigmata of Turner's syndrome. The levels of gonadotropin were not raised to post-menopausal levels. A chromosome study showed a 45,X/46,X,idic(X)(q22) karyotype. She was diagnosed as having Turner's syndrome.

High prevalence of primary ovarian insufficiency in girls and young women with Nijmegen breakage syndrome: evidence from a longitudinal study

CONTEXT

Nijmegen breakage syndrome (NBS) is a severe chromosomal instability disorder characterized by microcephaly, growth retardation, immune deficiency, and predisposition for malignancy. It is caused by hypomorphic mutations in the NBN gene, which product belongs to the protein complex critical for processing DNA double-strand breaks during mitotic and meiotic recombination. Data on gonadal function in patients with NBS are limited.

OBJECTIVE

Growth and sexual development, along with hormonal assays, were evaluated in girls and young women with NBS homozygous for c.657_661del5 mutation.

STUDY DESIGN AND PATIENTS

The group comprised 37 girls and young women with NBS (ages, 0.17-24.25 yr), followed between 1993 and 2008. Patients were divided into three age groups: 1) 1-3 yr; 2) 4-9 yr; and 3) 10 yr and older. Growth, puberty, concentrations of gonadotropins and 17-beta-estradiol, bone age, and pelvic ultrasound were assessed.

RESULTS

None of the patients presented a typical growth spurt; the adult height ranged between the 3rd and 25th centiles. Median bone age was delayed by 4.05 yr. Pubarche reached stadium P2 in eight patients and P3 in two patients. In all but one girl, thelarche did not exceed Th2, with low 17beta-estradiol levels. Gonadotropin levels showed a biphasic pattern, with median FSH values of 55.0, 10.9, and 81.9 IU/liter, and LH of 3.2, 0.8, and 21.0 IU/liter in consecutive age groups. Ultrasound visualized small ovaries or solid streaks and the hypoplastic uterus.

CONCLUSIONS

Primary ovarian insufficiency and the associated hypergonadotropic hypogonadism are hallmark manifestations in girls and young women with NBS. Our findings emphasize the need for long-term endocrinological and interdisciplinary supervision of these patients.

Psychological and behavioural aspects of patients with Turner syndrome from childhood to adulthood: a review of the clinical literature

Turner syndrome (TS) is a chromosomal abnormality, which occurs in approximately one of every 2500 female births. Short stature, infertility, additional physical abnormalities, skeletal and medical problems may be present. Genetic, hormonal, and medical problems associated with TS are likely to affect psychosexual development of female adolescent patients, and thus influence their psychological functioning, behavior patterns, social interactions and learning ability. Although TS constitutes a chronic medical condition, with possible physical, social and psychological complications in a woman's life, hormonal and estrogen replacement therapy and assisted reproduction, are treatments that can be helpful for TS patients and improve their quality of life. Authors report on a review of the research literature clinical aspects of the syndrome as well as the beneficial effect of hormonal therapy in such patients.

Gonadotropin secretion in girls with turner syndrome measured by an ultrasensitive immunochemiluminometric assay

BACKGROUND/AIM

Gonadotropin levels measured by radioimmunoassays are high in girls with Turner syndrome (TS), but overlap significantly with those of normal girls. We hypothesized that gonadotropin levels would be above the normal range in TS when measured by ultrasensitive assays.

METHODS

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured in 68 TS, and 133 control girls using ultrasensitive immunochemiluminometric assays (ICMA).

RESULTS

FSH levels in TS and normal girls were highest in early childhood (56.0 +/- 39.7 and 2.3 +/- 1.8 IU/l, respectively), declined at 6-10 years of age (11.3 +/- 13.1 and 1.8 +/- 0.9 IU/l, respectively), and then increased again (104.4 +/- 68.9 and 4.9 +/- 2.4 IU/l, respectively). FSH was in the normal range on 11 of 27 occasions in TS girls with ages 5-10 years, and on 3 of 44 occasions in >10 years. Although average LH values were higher than those of controls, they often overlapped the normal range.

CONCLUSION

A significant number of TS girls have normal gonadotropins by ICMA. Spontaneous gonadotropin levels are not an adequate screening test for the diagnosis of TS but may prove useful for predicting the gonadal function and determining the appropriate timing of estrogen replacement therapy.