Central precocious puberty in 48,XXYY Klinefelter syndrome variant

Treatment of congenital adrenal hyperplasia and Klinefelter Syndrome with central precocious puberty: a case report

The simultaneous occurrence of Klinefelter syndrome (KS) and congenital adrenal hyperplasia (CAH) is extremely rare, as the former causes androgen deficiency, while the latter results in androgen excess. In addition, central precocious puberty (CPP) will occur, which is caused by the activation of the hypothalamic-pituitary-gonadal (HPG) axis by androgens. We present the 7th reported case of simultaneous KS and CAH in a boy with CPP due to protopathy of CAH. He presented with increased gonadotropin and excessive androgen levels, and was diagnosed with KS due to his unexpected karyotype analysis results. This is the first reported case of an association between KS and CAH to undergo gonadotropin-releasing hormone analog (GnRHa) and recombinant human growth hormone (rhGH) therapy to increase his predicted final height. His predicted adult height was approximately 160 cm by estimation using the bone age as well as current height, which is much taller than the estimated height before treatment. Although KS may cause hypogonadism, the patient should be administered GnRHa and rhGH therapy if simultaneous CAH, CPP, and KS are present to increase the patient's predicted final height. Excessive androgen levels may mask the symptoms of KS-related hypogonadism during childhood; however, the patient should be made aware of the possibility of hypogonadism developing in the future.

Idiopathic central precocious puberty in a Klinefelter patient: highlights on gonadotropin levels and pathophysiology

Background

Idiopathic central precocious puberty (ICPP) is supposed to be non-existent in a context of testicular destruction that is typically present in Klinefelter syndrome (KS). Herein, we describe a rare case of ICPP in a Klinefelter patient (47,XXY) with 2 maternal X chromosomes. Moreover, we highlight the differences in gonadotropin levels in comparison to males with ICPP and a normal karyotype.

Case presentation

An 8 years old boy with a history of cryptorchidism was evaluated for precocious puberty (Tanner staging: P2/G3). Both testes measured 25x35mm. His hormonal profile confirmed a central origin of precocious puberty with high serum testosterone (4.3 ng/ml), luteinizing hormone [LH (3.5 UI/l)] and follicle stimulating hormone [FSH (7.7 UI/l)] levels. Luteinizing hormone-releasing hormone (LHRH) test amplified LH and FSH secretion to 24 and 14 UI/l respectively. Brain magnetic resonance imaging (MRI) was normal. No MKRN3 mutation was detected. He was treated for ICPP for two years. During puberty, he suffered from hypergonadotropic hypogonadism leading to the diagnosis of KS (47,XXY karyotype). Chromosomal analysis by fluorescent multiplex polymerase chain reaction (PCR) using X chromosome microsatellite markers identified 2 maternal X chromosomes.

Analysing 8 cases of KS developing ICPP (our reported case and 7 other published cases) revealed that these KS patients with ICPP have higher LH and FSH levels during ICPP episode than in ICPP patients with a normal karyotype (ICPP with KS vs ICPP with a normal karyotype: LH levels 9.4 ± 12 vs 1.1 ± 0.6 UI/l; FSH levels 23.1 ± 38.5 vs 2.7 ± 1.5 UI/l). Furthermore, their response to gonadotropin-releasing hormone (GnRH) stimulation is characterized by excessive LH and FSH secretion (LH levels post-GnRH: 58 ± 48 vs 15.5 ± 0.8 UI/l; FSH levels post-GnRH: 49.1 ± 62.1 vs 5.7 ± 3.9 UI/l).

Conclusions

ICPP in boys is extremely rare. The pathophysiology of ICPP in KS is unknown. However, maternal X supplementary chromosome and early testicular destruction may play a significant role in the initiation of ICPP, in part explaining the relative “overrepresentation of ICPP in KS. Thus, karyotype analysis could be considered for boys suffering from ICPP, especially if testicular size is smaller or gonadotropins are significantly elevated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12610-020-00117-1.

Central precocious puberty as a prelude to hypogonadism in a patient with Klinefelter syndrome

INTRODUCTION

Incomplete pubertal development is a common phenomenon found in patients with Klinefelter syndrome (KFS). KFS combined with central precocious puberty (CPP) rarely occurs. We herein report a rare case of KFS with CPP and review several studies to determine the possible mechanism underlying this condition.

CASE PRESENTATION

An 8-year, 5-month-old male patient was admitted to our hospital because of enlargement of the penis and small testes. Laboratory evaluation revealed high luteinizing hormone and follicle-stimulating hormone levels, a high testosterone level, and the 48,XXYY karyotype. He was treated with triptorelin. One year later, the patient's testosterone level decreased and pubertal arrest occurred.

CONCLUSION

The literature review in this study showed that the occurrence of hypogonadism combined with CPP is not unique to patients with KFS; it has also been reported in individuals with Turner syndrome, adrenal hypoplasia congenita, and other diseases. Such individuals share common features including partial hypogonadism and a normal hypothalamic-pituitary-gonadal axis. CPP is considered a prelude to hypogonadism, and treatment with a gonadotropin-releasing hormone agonist may prevent gonadal failure.

Central precocious puberty as a prelude of gonad dysplasia

There is increasing evidence that patients with gonad dysplasia, as characterized by absent or incomplete puberty, can also exhibit central precocious puberty (CPP). Herein, we review the reported cases that manifest with both gonad dysplasia and CPP. Further, we examine the hypothesis that these patients exhibit a normal hypothalamic-pituitary-gonadal axis, hypogonadism, and the presence of residual gonadal function, and that the onset of disease is related to early initiation of the hypothalamic-pituitary-gonadal axis. Thus, we suggest that CPP is a prelude of some partial hypogonadism.

Endocrine function in a 48,XXYY adult with type 2 diabetes: case report with a review of the literature

We present the clinical, biological, endocrinal and psychological characteristics of a 48,XXYY adult. The 43-year-old male examined is the first reported case of this XY polysomy concomitant with type 2 diabetes. Endocrine investigations suggested dysfunction of Leydig and Sertoli cells whereas the pituitary function appeared normal. We compare the phenotypic, behavioral and pathological features of the syndrome in our patient with other reports in the literature.

Molecular and cytogenetic characterization of a non-mosaic isodicentric Y chromosome in a patient with Klinefelter syndrome

We report on an adult male with Klinefelter phenotype and an isodicentric Y chromosome (47,XX,+idic(Y)(q12)), a combination which has to the best of our knowledge not been reported before. The patient was hospitalized in forensic psychiatry because of repeated delinquency, aggressive, aberrant and inappropriate behavior, and borderline intelligence. Molecular cytogenetic studies (FISH) showed that the SRY gene was present on both ends of the idicY, while there was only one signal for the Yq subtelomere probe. Molecular investigations by multiplex PCR, using STS markers covering the short and long arm of the Y chromosome did not indicate a deletion of Y chromosomal material. Molecular investigations of STR markers located on Xp22.3 and Xq28 indicated paternal origin of the additional X chromosome and an error in paternal meiosis I. Results of FISH analysis and molecular investigations are compatible with a phenotype as described for individuals with a 48,XXYY karyotype and support the findings that isodicentric Y chromosomes are frequently accompanied by other sex chromosomal abnormalities.

Postmortem diagnosis of "occult" Klinefelter syndrome in a patient with chronic renal disease and liver cirrhosis

This report describes a patient not suspected of having Klinefelter syndrome during life but diagnosed with it following postmortem examination using fluorescent in situ hybridization (FISH) for sex chromosomes and hormone serum analysis. A 49-year-old Japanese man had a history of nephrosis, heavy alcohol consumption, diabetes mellitus, and liver cirrhosis and had been undergoing dialysis for 10 years. He died of ruptured esophageal varices. Autopsy revealed hypogonadism, suggesting Klinefelter syndrome. This was confirmed by FISH, which showed a mosaic 46XY, 47XXY karyotype, and by serum analysis, which revealed high luteinizing hormone and follicle-stimulating hormone and low testosterone levels. Autopsy also revealed a nodular, bilateral, testicular Leydig cell hyperplasia. This report illustrates the value of postmortem laboratory investigations, particularly FISH for sex chromosomes and serum hormone analysis, for the demonstration of clinically uncertain or "occult" Klinefelter syndrome.