Long-term health outcomes of adults with McCune-Albright syndrome

Clinical Characteristics and Management of Patients With McCune-Albright Syndrome With GH Excess and Precocious Puberty: A Case Series and Literature Review

Background

McCune-Albright syndrome is a rare disorder characterized by fibrous dysplasia, café au lait skin spots, and hyperfunctioning endocrinopathies. The coexistence of precocious puberty and growth hormone excess in McCune-Albright syndrome is rare. Both conditions can manifest as accelerated growth, and treatments can be more challenging for such patients. This study aimed to describe the clinical manifestations of combined GH excess and PP in the context of McCune-Albright syndrome and analyze the clinical features and treatments of these patients.

Method

Clinical data from 60 McCune-Albright syndrome patients from Peking Union Medical College Hospital were obtained. The demographic characteristics, growth hormone, insulin-like growth factor-1, prolactin, alkaline phosphatase, and sex hormone levels; growth velocity; and bone age data were obtained. The growth velocity Z-score, bone age over chronological age ratio, and predicted adult height Z-score were calculated before and after treatment. Published studies and case reports were systemically searched, and data on demographic, clinical, and biochemical characteristics and treatment outcomes were obtained.

Results

We reviewed seven patients among 60 McCune-Albright syndrome patients at Peking Union Medical College Hospital (5 female) and 39 patients (25 female) from the published literature. Six of the seven patients from Peking Union Medical College Hospital and half of the patients from the published studies were pediatric patients. These patients had increased growth velocity Z-scores and bone age over chronological age ratios. After good control of both conditions, the growth velocity Z-score and bone age over chronological age ratio decreased significantly, and the predicted adult height Z-score increased. The final heights and predicted adult height Z-scores were not impaired in patients with gigantism. All the patients had craniofacial fibrous dysplasia associated with optic and otologic complications.

Conclusion

McCune-Albright syndrome with growth hormone excess and precocious puberty is more common in girls. Patients have accelerated linear growth and advanced skeletal age, and early and good control of both conditions leads to a reduced growth velocity and stabilized bone age. The predicted adult and final heights are not negatively affected when growth hormone excess is diagnosed in pediatric patients.

Juvenile Granulosa Cell Tumor as the Presenting Feature of McCune-Albright Syndrome

Introduction

GNAS mutations have been reported in both McCune-Albright syndrome (MAS) and juvenile granulosa cell tumors (JGCT) but have never been reported simultaneously in the same patient.

Case Presentation

A 15-year-old girl developed secondary oligomenorrhea. Laboratory studies revealed suppressed gonadotropin levels with markedly elevated estradiol and inhibin B levels. Pelvic ultrasound showed a 12-cm heterogeneous right adnexal mass; pelvic magnetic resonance imaging to further characterize the mass displayed heterogeneous bilateral femoral bone lesions initially concerning for metastatic disease. Positron emission tomography/computed tomography showed minimal ¹⁸F-fluorodeoxyglucose (FDG) uptake in the pelvic mass but unexpectedly revealed FDG uptake throughout the skeleton, concerning for polyostotic fibrous dysplasia in the context of MAS. The adnexal mass was excised and pathology confirmed a JGCT. The patient’s affected bone and JGCT tissue revealed the same pathogenic GNAS p.R201C mutation, while her peripheral blood contained wild-type arginine at codon 201.

Conclusion

This mutation has been previously reported in cases of MAS and JGCT but never simultaneously in the same patient. This demonstration of a GNAS mutation underlying both JGCT and MAS in the same patient raises questions about appropriate surveillance for patients with these conditions.

Fertility in McCune Albright syndrome female: A case study focusing on AMH as a marker of ovarian dysfunction and a literature review

BACKGROUND

The molecular basis of McCune Albright syndrome (MAS) is a recurrent GNAS Postzygotic gain of function sporadic mutation, resulting in a mosaic disease. Most of girls present precocious puberty, caused by the development of recurrent ovarian cysts with autonomous Hyperestrogenic stimulation. After menarche, the majority of patients with ovarian GNAS mutation have menstrual disturbances and infertility.

OBJECTIVES

We wanted to focus on the fertility of MAS females and propose an appropriate management, by a detailed case report and an exhaustive review of the literature on fertility and pregnancy in MAS females.

RESULTS

We present the case of a 29-year-old MAS female, who had previously undergone a unilateral ovariectomy and was managed by in vitro fertilization (IVF). Eight oocytes with many morphological abnormalities were retrieved. The GNAS mutation was found at a low frequency in follicular cells. The ovarian histopathological examination showed developing follicles of all stages, strongly expressing AMH by immunohistochemistry. In addition, AMH was high (45.5 pmol/L) and the AMH / AFC ratio (5.69 pmol/L per follicle) was much higher than in PCOS and control groups (2.16, and 1.34 respectively).

CONCLUSIONS

Ovarian and endometrial involvement can be responsible for infertility in MAS women. IVF and oophorectomy may be useful in management. The genetic characterization of the different tissues may have a prognostic utility. Moreover, we suggest that the AMH could be a marker of the ovarian activity in MAS. Further studies are needed to clarify the potential oocyte abnormalities and the risk of miscarriages in order to guide genetic counseling.

McCune Albright Syndrome: Gastrointestinal Polyps and Platelet Dysfunction over 12 Years

BACKGROUND AND OBJECTIVE

Gastrointestinal (GI) polyps with unknown malignant potential and a platelet storage pool deficiency that increases the risk of severe intraoperative and other types of bleeding have been identified in McCune-Albright syndrome (MAS). The natural course of these disorders has not been well characterized. The aim of this study was to report the follow-up of GI polyps and platelet dysfunction (PD) in a cohort of 28 patients with MAS.

METHODS

Twenty-eight patients with MAS (15 females) were included. Endoscopic screening for GI polyps was undertaken in 14 subjects and 19 were tested for PD.

RESULTS

Six subjects (5 males) were diagnosed with GI polyps at a median age of 23 (range 15-43) years, and were monitored for a median period of 8 (range 4.5-11.5) years. At endoscopic follow-up, the 4 patients with hamartomatous polyps at first endoscopy had either normal findings (n = 2), or duodenal gastric metaplasia (n = 2). Two patients with caecal polyps were identified. Of 8 subjects with a platelet storage pool deficiency, 5 required transfusions during surgery, and subsequent platelet cover in 2 markedly reduced intraoperative blood loss.

CONCLUSIONS

New polyps with uncertain malignant potential are diagnosed after long term follow-up in MAS. Platelet cover reduces the need for red blood cell transfusion during orthopaedic surgery and may be useful to reduce non-operative bleeding events. We recommend regular upper and lower endoscopy and screening for PD in all MAS patients.

Genetics of Acromegaly and Gigantism

Growth hormone (GH)-secreting pituitary tumours represent the most genetically determined pituitary tumour type. This is true both for germline and somatic mutations. Germline mutations occur in several known genes (AIP, PRKAR1A, GPR101, GNAS, MEN1, CDKN1B, SDHx, MAX) as well as familial cases with currently unknown genes, while somatic mutations in GNAS are present in up to 40% of tumours. If the disease starts before the fusion of the epiphysis, then accelerated growth and increased final height, or gigantism, can develop, where a genetic background can be identified in half of the cases. Hereditary GH-secreting pituitary adenoma (PA) can manifest as isolated tumours, familial isolated pituitary adenoma (FIPA) including cases with AIP mutations or GPR101 duplications (X-linked acrogigantism, XLAG) or can be a part of systemic diseases like multiple endocrine neoplasia type 1 or type 4, McCune-Albright syndrome, Carney complex or phaeochromocytoma/paraganglioma-pituitary adenoma association. Family history and a search for associated syndromic manifestations can help to draw attention to genetic causes; many of these are now tested as part of gene panels. Identifying genetic mutations allows appropriate screening of associated comorbidities as well as finding affected family members before the clinical manifestation of the disease. This review focuses on germline and somatic mutations predisposing to acromegaly and gigantism.

Auxological and Endocrinological Features in Children With McCune Albright Syndrome: A Review

McCune-Albright syndrome is a rare and challenging congenital sporadic disease involving the skin and skeletal and endocrine systems with a prevalence ranges from one in 100,000 to 1,000,000. In addition to the classical triad of fibrous dysplasia of bone, café au lait pigmented skin lesions and precocious puberty, other multiple endocrinological features, including hyperthyroidism, growth hormone excess, hypercortisolism, and hypophosphatemic rickets, have been reported. A brief review of the syndrome in children is here reported.

Gynecologic and reproductive outcomes in fibrous dysplasia/McCune-Albright syndrome

Background

Autonomous ovarian activation with recurrent estrogen-producing cysts is a hallmark feature of the rare bone and endocrine disorder fibrous dysplasia/McCune-Albright syndrome. Precocious puberty in girls with McCune-Albright syndrome has been well-described, however long-term effects on gynecologic and reproductive function are unknown. Concerningly, case reports have described poor skeletal outcomes associated with pregnancy in women with fibrous dysplasia.

Methods

Thirty-nine women with fibrous dysplasia/McCune-Albright syndrome were evaluated as part of a natural history study. Clinical, radiographic, and biochemical data were reviewed. Women were contacted to obtain detailed menstrual and reproductive histories.

Results

Abnormal uterine bleeding affected 77% of women (30/39), and was associated with severe anemia requiring blood transfusion in 3 cases. Nine women underwent hysterectomy for management of bleeding, including 67% (6/9) at the unusually young age of less than age 35 years. Infertility affected 43% of women (9/21), including 2 women who developed primary ovarian insufficiency after undergoing surgical treatment of ovarian cysts. Of 25 spontaneous pregnancies in 14 women, 35% (8) were unplanned. Among the 14 pregnancies, pregnancy was associated with no change in bone pain in 7 subjects (53%), increased bone pain in 4 subjects (31%), and decreased bone pain in 2 subjects (15%). No additional skeletal complications were reported during pregnancies.

Conclusions

Women with fibrous dysplasia/McCune-Albright syndrome report a high prevalence of gynecologic morbidity and reduced fertility. There is no clear association between pregnancy and poor skeletal outcomes in this population.

Clinical and translational pharmacological aspects of the management of fibrous dysplasia of bone

Fibrous dysplasia (FD) is a genetic, noninheritable rare bone disease caused by a postzygotic activating mutation of the α subunit of the stimulatory G‐protein causing increased abnormal bone formation leading to pain, deformity and fractures. To date, no cure has been identified for FD/McCune–Albright syndrome (MAS) and treatment is symptomatic and aimed at decreasing pain and/or local bone turnover. Various drugs have been used to achieve clinical improvement in FD/MAS patients including bisphosphonates and denosumab, however further translational studies are also warranted to address unresolved pathophysiological issues and explore novel pharmacological targets for the management of FD/MAS.

In this article, we review literature on the medical treatment of FD/MAS, discuss the unresolved pathophysiological issues and explore novel pharmacological targets for the management of FD/MAS.

Growth hormone-Insulin-like growth factor 1 axis hyperactivity on bone fibrous dysplasia in McCune-Albright Syndrome

CONTEXT

In fibrous dysplasia (BFD), normal bone and bone marrow are replaced by fibro-osseous tissue, leading to fracture, deformity and pain. BFD may be isolated, or in association with cutaneous hyperpigmentation and/or hyperfunctioning endocrinopathies, termed McCune-Albright syndrome (MAS). GH hypersecretion has been described in 10%-20% of MAS-BFD patients. Aim of the study was to determine the impact of GH-insulin like growth factor 1 (IGF1) axis hyperactivity on MAS-BFD morbidities and the efficacy of GH excess therapy.

DESIGN AND PATIENTS

A multicentric cross-sectional analysis was conducted on three different MAS cohorts. From 195 MAS patients, 37 subjects (19%) with GH excess were identified and compared with 34 MAS controls without GH hypersecretion.

RESULTS

Mean head circumference SDS was significantly higher in GH excess: 4.025 SDS vs 0.683 SDS (P < .0001). The risk of optic neuropathy (Odds ratio 4.231; P = .039), hearing deficit (Odds ratio 2.961; P = .0481), facial asymmetry (Odds ratio 6.563; P = .0192), malignancies (Odds ratio 15.24; P = .0173) were higher in GH excess group. Overall, pharmacotherapy (octreotide alone 10-30 mg/mo or with pegvisomant 10-20 mg/d) was effective in IGF1 normalization (IGF1 Z-score between -2 and +2 SDS) in 21/29 patients (72.4%) with good compliance to the regimen. Late diagnosis and GH excess treatment after 16 years old of age was associated with an increased risk of optic neuropathy (Odds ratio 4.500; P = .0491) and growth of pituitary adenomas (Odds ratio 7.846; P = .050).

CONCLUSIONS

GH-IGF1 hyperactivity increases risk of morbidities in MAS. Medical therapy is effective in normalizing IGF1 in most patients, and early treatment during paediatric age is associated with a decreased risk of optic neuropathy and GH-secreting adenomas growth.