Serum Anti-Müllerian Hormone in the Prediction of Response to hCG Stimulation in Children With DSD

PROKR2 mutations and SPRY4 variants with uncertain significance in a Kallmann syndrome family: Incomplete penetrance

Kallmann syndrome is a rare genetic disease characterized by the idiopathic hypogonadotropic hypogonadism with hyposmia or anosmia, which exhibits considerable heterogeneity in genotype and phenotype. Herein, we reported a 32-year-old male patient with Kallmann syndrome in a family associated with heterozygous mutations in PROKR2 and SPRY4 genes. The genotyping results indicated PROKR2 mutations and SPRY4 variants of uncertain significance, which might be incompletely penetrant in this family.

Is it possible to separate the testicular and ovarian components of an ovotestis?

The presence of an ovotestis is a rare etiology of differences of sex development. Histologically, ovotestis come in two forms: 1) Mixed or 2) Bipolar.

OBJECTIVE

We hypothesize that it is surgically impossible to cleanly separate and preserve either the testicular or ovarian component of an ovotestis.

STUDY DESIGN

Twenty human gonads with a previous diagnosis of ovotestis were re-sectioned in entirety and re-stained with markers for testicular (SOX9, TSPY, SALL4, DDX4, cP450, AR, α-actin) and ovarian tissue (FOXL2, SALL4, DDX4). Histologic sections were photographed at low power to confirm the presence of the entire cross section of the ovotestis. High power was used to confirm an ovotestis based on the presence of both seminiferous cords (testis) and follicles (ovary).

RESULTS

Six of twenty ovotestis did not meet our criterion for the diagnosis of ovotestis lacking the histologic evidence of both testicular and ovarian tissue (lacking ovarian follicles). The remaining 13 patients in which 14 separate specimens were evaluated, contained ovotestis defined by the presence of both seminiferous cords and ovarian follicles. Seven of these specimens had low power confirmational histologic images that included the entire ovotestis and could be completely evaluated for a potential surgical plane of separation. The other seven specimens were consistent with an ovotestis biopsy without complete borders. For the seven specimens that included the entire ovotestis, 6 of the 7 had ovotesticular cords and 3 had the presence of ovotesticular follicles.

DISCUSSION

None of the seven complete specimens had a clear surgical plane where testicular or ovarian components could be isolated cleanly. Often the ovarian component was composed of a thin layer of follicles, surrounded the testicular component with an in-between, mixed layer of both seminiferous cords and follicles. The remaining seven ovotestis biopsy specimens also did not have a clear plane for surgically isolating either the testicular or ovarian compartment.

CONCLUSION

Based on the histologic evaluation of the entire ovotestis as well as ovotestis biopsy specimens it does not appear possible to surgically separate the testicular and ovarian component. We have reservations with the concept in both mixed and bipolar ovotestis that it is possible to surgically preserve either the ovarian or testicular component without leaving incongruent tissue. The clinical implications of leaving gonadal tissue inconsistent with the patient's gender identity remains unknown.

Frequency of Delayed Puberty in Boys with Contemporary Management of Duchenne Muscular Dystrophy

Objective

Delayed puberty is thought to be common in boys with Duchenne muscular dystrophy (DMD) treated with long term oral glucocorticoid. The aim of this study was to report the frequency of delayed puberty in DMD from examination by a paediatric endocrinologist alongside detailed endocrine investigations.

Methods

All boys with DMD aged at least 14 years in January 2022 known to the paediatric neuromuscular service (2016-2022) were included. Delayed puberty was defined based on testicular volume and genital staging in comparison to a published puberty nomogram.

Results

Twenty-four out of 37 boys (65%) had evidence of delayed puberty and 23/24 (96%) were on glucocorticoid therapy, all of whom were on daily glucocorticoid. However, 7/13 (54%) with normal timing of puberty were on glucocorticoid; 2/7 (29%) were on the intermittent regimen. Of those who were on daily glucocorticoid therapy at the time of assessment of puberty, 23/28 (82%) had evidence of delayed puberty. In boys with delayed puberty, endocrine investigations showed low luteinizing hormone with undetectable testosterone levels, a pre-pubertal response with lutenizing hormone releasing hormone test and sub-optimal testosterone levels with prolonged human chorionic gonadotropin stimulation.

Conclusion

The frequency of delayed puberty in boys with DMD was 65%. Eighty-two percent of adolescent boys with DMD on daily glucocorticoid had evidence of delayed puberty. Biochemical investigations point to functional central hypogonadism in these adolescents. Our data supports the routine monitoring of puberty in boys with DMD.

Assessment of testicular function in boys and adolescents

OBJECTIVE

The hypothalamic-pituitary-testicular axis is characterised by the existence of major functional changes from its establishment in fetal life until the end of puberty. The assessment of serum testosterone and gonadotrophins and semen analysis, typically used in the adult male, is not applicable during most of infancy and childhood. On the other hand, the disorders of gonadal axis have different clinical consequences depending on the developmental stage at which the dysfunction is established. This review addresses the approaches to evaluate the hypothalamic-pituitary-testicular axis in the newborn, during childhood and at pubertal age.

DESIGN

We focused on the hormonal laboratory and genetic studies as well as on the clinical signs and imaging studies that guide the aetiological diagnosis and the functional status of the gonads.

RESULTS

Serum gonadotrophin and testosterone determination is useful in the first 3-6 months after birth and at pubertal age, whereas AMH and inhibin B are useful biomarkers of testis function from birth until the end of puberty. Clinical and imaging signs are helpful to appraise testicular hormone actions during fetal and postnatal life.

CONCLUSIONS

The interpretation of results derived from the assessment of hypothalamic-pituitary-testicular in paediatric patients requires a comprehensive knowledge of the developmental physiology of the axis to understand its pathophysiology and reach an accurate diagnosis of its disorders.

SEC31A may be associated with pituitary hormone deficiency and gonadal dysgenesis

PURPOSE

Disorders/differences of sex development (DSD) result from variants in many different human genes but, frequently, have no detectable molecular cause.

METHODS

Detailed clinical and genetic phenotyping was conducted on a family with three children. A Sec31a animal model and functional studies were used to investigate the significance of the findings.

RESULTS

By trio whole-exome DNA sequencing we detected a heterozygous de novo nonsense SEC31A variant, in three children of healthy non-consanguineous parents. The children had different combinations of disorders that included complete gonadal dysgenesis and multiple pituitary hormone deficiency. SEC31A encodes a component of the COPII coat protein complex, necessary for intracellular anterograde vesicle-mediated transport between the endoplasmic reticulum (ER) and Golgi. CRISPR-Cas9 targeted knockout of the orthologous Sec31a gene region resulted in early embryonic lethality in homozygous mice. mRNA expression of ER-stress genes ATF4 and CHOP was increased in the children, suggesting defective protein transport. The pLI score of the gene, from gnomAD data, is 0.02.

CONCLUSIONS

SEC31A might underlie a previously unrecognised clinical syndrome comprising gonadal dysgenesis, multiple pituitary hormone deficiencies, dysmorphic features and developmental delay. However, a variant that remains undetected, in a different gene, may alternatively be causal in this family.

Anti-Müllerian hormone, testicular descent and cryptorchidism

Anti-Müllerian hormone (AMH) is a Sertoli cell-secreted glycoprotein involved in male fetal sex differentiation: it provokes the regression of Müllerian ducts, which otherwise give rise to the Fallopian tubes, the uterus and the upper part of the vagina. In the first trimester of fetal life, AMH is expressed independently of gonadotropins, whereas from the second trimester onwards AMH testicular production is stimulated by FSH and oestrogens; at puberty, AMH expression is inhibited by androgens. AMH has also been suggested to participate in testicular descent during fetal life, but its role remains unclear. Serum AMH is a well-recognized biomarker of testicular function from birth to the first stages of puberty. Especially in boys with nonpalpable gonads, serum AMH is the most useful marker of the existence of testicular tissue. In boys with cryptorchidism, serum AMH levels reflect the mass of functional Sertoli cells: they are lower in patients with bilateral than in those with unilateral cryptorchidism. Interestingly, serum AMH increases after testis relocation to the scrotum, suggesting that the ectopic position result in testicular dysfunction, which may be at least partially reversible. In boys with cryptorchidism associated with micropenis, low AMH and FSH are indicative of central hypogonadism, and serum AMH is a good marker of effective FSH treatment. In patients with cryptorchidism in the context of disorders of sex development, low serum AMH is suggestive of gonadal dysgenesis, whereas normal or high AMH is found in patients with isolated androgen synthesis defects or with androgen insensitivity. In syndromic disorders, assessment of serum AMH has shown that Sertoli cell function is preserved in boys with Klinefelter syndrome until mid-puberty, while it is affected in patients with Noonan, Prader-Willi or Down syndromes.

Gonadal Function in Boys with Bilateral Undescended Testes

Background

Bilateral undescended testes (BUDT) may be a marker of an underlying condition that affects sex development or maturation.

Aims

To describe the extent of gonadal dysfunction in cases of BUDT who had systematic endocrine and genetic evaluation at a single tertiary pediatric center.

Methods

A retrospective review was conducted of all boys with BUDT who had endocrine evaluation between 2008 and 2021 at the Royal Hospital for Children, Glasgow (RHCG). Continuous variables were analyzed using Mann-Whitney U and non-continuous variables using Fisher's exact, via Graphpad Prism v 8.0. Multivariable logistic regression was used to identify any associations between groups. A P < .05 was considered statistically significant.

Results

A total of 243 bilateral orchidopexies were performed at RHCG between 2008 and 2021. Of these 130 (53%) boys were seen by the endocrine team. The median (range) age at first orchidopexy was 1 year (0.2, 18.0) with 16 (12%) requiring re-do orchidopexy. The median External Masculinization Score of the group was 10 (2, 11) with 33 (25%) having additional genital features. Of the 130 boys, 71 (55%) had extragenital anomalies. Of the 70 who were tested, a genetic abnormality was detected in 38 (54%), most commonly a chromosomal variant in 16 (40%). Of the 100 who were tested, endocrine dysfunction was identified in 38 (38%).

Conclusion

Genetic findings and evidence of gonadal dysfunction are common in boys who are investigated secondary to presentation with BUDT. Endocrine and genetic evaluation should be part of routine clinical management of all cases of BUDT.

Thioredoxin Reductase 2 Variant as a Cause of Micropenis, Undescended Testis, and Selective Glucocorticoid Deficiency

INTRODUCTION

Variants in genes that play a role in maintaining cellular redox homeostasis in adrenocortical cells may be associated with glucocorticoid deficiency, and it is unclear whether these cases may be associated with a wider phenotype. However, to date, only 1 case of a genetic variant in thioredoxin reductase type 2 (TXNRD2) in a South Asian kindred with familial glucocorticoid deficiency has been reported.

CASE PRESENTATION

The index case was diagnosed with selective glucocorticoid deficiency at 10 years of age. He had a history of a small penis and a right undescended testis, which subsequently required an orchidopexy. The parents were of Pakistani origin and first cousins. The boy's gonadal function was normal and autosomal recessive missense homozygous variants p.Val361Met;Val361Met in TXNRD2 were identified in him by whole-genome sequencing. Functional studies were performed using peripheral blood mononuclear cells from the patient, unaffected parents, and four age-matched healthy boys. Compared to the carriers and controls, the case had lower TXNRD2 protein on immunoblotting using anti-TXNRD2 antibody (1.3-fold), 95% CI: 1.8 (1.5-2.1), lower mRNA expression of TXNRD2 on quantitative RT-PCR (1.6-fold), 95% CI: 1.1 (0.7-1.4), and a lower glutathione:oxidized glutathione ratio (6.7-fold), 95% CI: 2.0 (1.6-2.4).

CONCLUSIONS

In addition to confirming the critical role that TXNRD2 serves in maintaining adrenal function, by reporting the findings of atypical genitalia, this case further extends the phenotype.

Monorchidism in a Phenotypic Mare With a 64,XY, SRY-Positive Karyotype

Disorders of sexual development (DSD) are associated with atypical chromosomal, gonadal, or phenotypic sex. It is likely that the number of cases of DSD are underestimated in the equine population. Monorchidism in the horse is very rare. This case report describes the clinical assessment of a phenotypic mare with stallion-like behavior which led to the diagnosis of a DSD. A 4-year-old Quarter Horse mare presented in good body condition, with normal external genitalia for a mare, and normal mammary glands with two bilaterally symmetric teats. No uterus, cervix, or gonads were detected on transrectal palpation. Transrectal ultrasonography revealed a single gonad in the right dorsal abdomen with the morphologic appearance of a testicle. Presurgical hormonal evaluation revealed elevated serum testosterone and anti-Müllerian hormone (AMH) concentrations. The right gonad was successfully removed via standing exploratory laparoscopy and submitted for histopathology. No gonad was identified on the left side during laparoscopy. Histopathologic examination confirmed that the excised gonad was a testicle. Cytogenetic and molecular analysis revealed a 64,XY, SRY-positive chromosomal constitution. Hormonal evaluation 5 weeks after surgery revealed low serum testosterone and AMH levels. A diagnosis of monorchidism was based on ultrasound examination, laparoscopic exploration of the abdomen, removal of a single gonad, and a subsequent decrease in serum testosterone and AMH concentrations to basal levels. In summary, a combination of clinical signs, endocrine evaluation, chromosomal and molecular analysis, and histopathology can be used in the diagnosis of DSD conditions.

Diagnostic approach in 46, XY DSD: an endocrine society of bengal (ESB) consensus statement

OBJECTIVES

46, XY difference/disorder of sex development (DSD) is a relatively uncommon group of heterogeneous disorders with varying degree of underandrogenization of male genitalia. Such patients should be approached systematically to reach an aetiological diagnosis. However, we lack, at present, a clinical practice guideline on diagnostic approach in 46, XY DSD from this part of the globe. Moreover, debate persists regarding the timing and cut-offs of different hormonal tests, performed in these cases. The consensus committee consisting of 34 highly experienced endocrinologists with interest and experience in managing DSD discussed and drafted a consensus statement on the diagnostic approach to 46, XY DSD focussing on relevant history, clinical examination, biochemical evaluation, imaging and genetic analysis.

CONTENT

The consensus was guided by systematic reviews of existing literature followed by discussion. An initial draft was prepared and distributed among the members. The members provided their scientific inputs, and all the relevant suggestions were incorporated. The final draft was approved by the committee members.

SUMMARY

The diagnostic approach in 46, XY DSD should be multidisciplinary although coordinated by an experienced endocrinologist. We recommend formal Karyotyping, even if Y chromosome material has been detected by other methods. Meticulous history taking and thorough head-to-toe examination should initially be performed with focus on external genitalia, including location of gonads. Decision regarding hormonal and other biochemical investigations should be made according to the age and interpreted according to age-appropriate norms Although LC-MS/MS is the preferred mode of steroid hormone measurements, immunoassays, which are widely available and less expensive, are acceptable alternatives. All patients with 46, XY DSD should undergo abdominopelvic ultrasonography by a trained radiologist. MRI of the abdomen and/or laparoscopy may be used to demonstrate the Mullerian structure and/or to localize the gonads. Genetic studies, which include copy number variation (CNV) or molecular testing of a candidate gene or next generation sequencing then should be ordered in a stepwise manner depending on the clinical, biochemical, hormonal, and radiological findings.

OUTLOOK

The members of the committee believe that patients with 46, XY DSD need to be approached systematically. The proposed diagnostic algorithm, provided in the consensus statement, is cost effective and when supplemented with appropriate genetic studies, may help to reach an aetiological diagnosis in majority of such cases.

Testicular Sertoli Cell Hormones in Differences in Sex Development

The Sertoli cells of the testes play an essential role during gonadal development, in addition to supporting subsequent germ cell survival and spermatogenesis. Anti-Müllerian hormone (AMH) is a member of the TGF-β superfamily, which is secreted by immature Sertoli cells from the 8th week of fetal gestation. lnhibin B is a glycoprotein, which is produced by the Sertoli cells from early in fetal development. In people with a Difference or Disorder of Sex Development (DSD), these hormones may be useful to determine the presence of testicular tissue and potential for spermatogenesis. However, fetal Sertoli cell development and function is often dysregulated in DSD conditions and altered production of Sertoli cell hormones may be detected throughout the life course in these individuals. As such this review will consider the role of AMH and inhibin B in individuals with DSD.

Congenital Micropenis: Etiology And Management

In the newborn, penile length is determined by a number of androgen dependent and independent factors. The current literature suggests that there are interracial differences in stretched penile length in the newborn and although congenital micropenis should be defined as a stretched penile length of less than 2.5 SDS of the mean for the corresponding population and gestation, a pragmatic approach would be to evaluate all boys with a stretched penile length below 2 cm, as congenital micropenis can be a marker for a wide range of endocrine conditions. However, it remains unclear as to whether the state of micropenis, itself, is associated with any long-term consequences. There is a lack of systematic studies comparing the impact of different therapeutic options on long-term outcomes, in terms of genital appearance, quality of life, and sexual satisfaction. To date, research has been hampered by a small sample size and inclusion of a wide range of heterogeneous diagnoses; for these reasons, condition-specific outcomes have been difficult to compare between studies. Lastly, there is a need for a greater collaborative effort in collecting standardized data so that all real-world or experimental interventions performed at an early age can be studied systematically into adulthood.

Clinical Utility of Anti-Mullerian Hormone in Pediatrics

CONTEXT

Anti-Mullerian hormone (AMH) was originally described in the context of sexual differentiation in the male fetus but has gained prominence now as a marker of ovarian reserve and fertility in females. In this mini-review, we offer an updated synopsis on AMH and its clinical utility in pediatric patients.

DESIGN AND RESULTS

A systematic search was undertaken for studies related to the physiology of AMH, normative data, and clinical role in pediatrics. In males, AMH, secreted by Sertoli cells, is found at high levels prenatally and throughout childhood and declines with progression through puberty to overlap with levels in females. Thus, serum AMH has clinical utility as a marker of testicular tissue in males with differences in sexual development and cryptorchidism and in the evaluation of persistent Mullerian duct syndrome. In females, serum AMH has been used as a predictive marker of ovarian reserve and fertility, but prepubertal and adolescent AMH assessments need to be interpreted cautiously. AMH is also a marker of tumor burden, progression, and recurrence in germ cell tumors of the ovary.

CONCLUSIONS

AMH has widespread clinical diagnostic utility in pediatrics but interpretation is often challenging and should be undertaken in the context of not only age and sex but also developmental and pubertal stage of the child. Nonstandardized assays necessitate the need for assay-specific normative data. The recognition of the role of AMH beyond gonadal development and maturation may usher in novel diagnostic and therapeutic applications that would further expand its utility in pediatric care.

Society for Endocrinology UK Guidance on the initial evaluation of a suspected difference or disorder of sex development (Revised 2021)

It is paramount that any child or adolescent with a suspected difference or disorder of sex development (DSD) is assessed by an experienced clinician with adequate knowledge about the range of conditions associated with DSD and is discussed with the regional DSD service. In most cases, the paediatric endocrinologist within this service acts as the first point of contact but involvement of the regional multidisciplinary service will also ensure prompt access to specialist psychology and nursing care. The underlying pathophysiology of DSD and the process of delineating this should be discussed with the parents and affected young person with all diagnostic tests undertaken in a timely fashion. Finally, for rare conditions such as these, it is imperative that clinical experience is shared through national and international clinical and research collaborations.

Up-to-Date Clinical and Biochemical Workup of the Child and the Adolescent with a Suspected Disorder of Sex Development

BACKGROUND

The suspicion of a disorder of sex development (DSD) often arises at birth, when the newborn presents with ambiguous genitalia, or even during prenatal ultrasound assessments. Less frequently, the aspect of the external genitalia is typically female or male, and the diagnosis of DSD may be delayed until a karyotype is performed for another health issue, or until pubertal age when a girl presents with absence of thelarche and/or menarche or a boy consults for gynaecomastia and/or small testes.

SUMMARY

In this review, we provide a practical, updated approach to clinical and hormonal laboratory workup of the newborn, the child, and the adolescent with a suspected DSD. We focus on how to specifically address the diagnostic approach according to the age and presentation. Key Message: We particularly highlight the importance of a detailed anatomic description of the external and internal genitalia, adequate imaging studies or surgical exploration, the assessment of reproductive hormone levels - especially testosterone, anti-Müllerian hormone, 17-hydroxyprogesterone, and gonadotropins - and karyotyping.

Serum Anti-Müllerian Hormone in the Prediction of Response to hCG Stimulation in Children With DSD

INTRODUCTION

The relationship between serum anti-Müllerian hormone (AMH) and the testosterone response to human chorionic gonadotropin (hCG) stimulation test is unclear.

METHODS

Children who had hCG stimulation tests in one tertiary centre from 2001 to 2018 were included (n = 138). Serum testosterone was measured before (day 1 [D1]) and after 3 days (D4) of hCG stimulation. Sixty-one of these children also had prolonged hCG stimulation for 2 more weeks and serum testosterone measured after 21 days (D22). All children had a serum AMH measured on D1.

RESULTS

Of the 138 children, D4 testosterone was normal in 104 (75%). AMH was low in 24/138 (17%) children, and 16 (67%) of these had a low D4 testosterone. Median AMH in those who had a normal vs low D4 testosterone was 850 pmol/L (24, 2280) and 54 pmol/L (0.4, 1664), respectively (P < 0.0001). An AMH > 5th centile was associated with a low D4 testosterone in 18/118 (13%; P < 0.0001). Of the 61 children who had prolonged hCG stimulation, D22 testosterone was normal in 39 (64%). AMH was low in 10/61(16%) children and 9 (90%) of these had a low D22 testosterone. Median AMH in children who responded and did not respond by D22 was 639 pmol/L (107, 2280) and 261 pmol/L (15, 1034) (P < 0.0001).

CONCLUSION

A normal AMH may provide valuable information on overall testicular function. However, a low AMH does not necessarily predict a suboptimal testosterone response to hCG stimulation.