McCune-Albright syndrome. Orphanet J Rare Dis. 2008;3:12. [PMID: 18489744 PMCID: PMC2459161 DOI: 10.1186/1750-1172-3-12]

Dental-craniofacial manifestation and treatment of rare diseases

Rare diseases are usually genetic, chronic and incurable disorders with a relatively low incidence. Developments in the diagnosis and management of rare diseases have been relatively slow due to a lack of sufficient profit motivation and market to attract research by companies. However, due to the attention of government and society as well as economic development, rare diseases have been gradually become an increasing concern. As several dental-craniofacial manifestations are associated with rare diseases, we summarize them in this study to help dentists and oral maxillofacial surgeons provide an early diagnosis and subsequent management for patients with these rare diseases.

A case of autonomous cortisol secretion in a patient with subclinical Cushing's syndrome, GNAS mutation, and paradoxical cortisol response to dexamethasone

BACKGROUND

Increased urinary free cortisol in response to the oral administration of dexamethasone is a paradoxical reaction mainly reported in patients with primary pigmented nodular adrenocortical disease. Here, we describe the first case of subclinical Cushing's syndrome represented by autonomous cortisol secretion and paradoxical response to oral dexamethasone administration, harboring an activating mutation in the α subunit of the stimulatory G protein (GNAS).

CASE PRESENTATION

A 65-year-old woman was diagnosed with subclinical Cushing's syndrome during an evaluation for bilateral adrenal masses. Tumors of unknown origin were found in the heart, brain, thyroid gland, colon, pancreas, and both adrenal glands. Adenocarcinoma of the sigmoid colon and systemic brown-patchy skin pigmentation were also present. Her urinary cortisol levels increased in response to oral dexamethasone, while serum dehydroepiandrosterone-sulfate was not suppressed. After right adrenalectomy, genetic analysis of the resected tumor revealed the somatic GNAS activating mutation, p.R201H. Paradoxical urinary cortisol response persisted even after unilateral adrenal resection, although serum and urinary cortisol levels were attenuated.

CONCLUSIONS

This patient harbored a GNAS activating mutation, and presented with a mild cortisol- and androgen-producing adrenal adenoma. Administration of oral dexamethasone paradoxically increased cortisol levels, possibly via the stimulation of the cyclic adenosine monophosphate-dependent protein kinase A signaling pathway, which is seen in patients with pigmented nodular adrenocortical disease or Carney complex. GNAS mutations may provide clues to the mechanisms of hyper-function and tumorigenesis in the adrenal cortex, especially in bilateral adrenal masses accompanied by multiple systemic tumors. Examining GNAS mutations could help physicians detect extra-adrenal malignancies, which may contribute to an improved prognosis for patients with this type of Cushing's syndrome.

Pediatric endocrinology through syndromes

In everyday practice, a pediatric endocrinologist will face a variety of different endocrine issues (such as short or tall stature, dysthyroidism, abnormal pubertal timing or impaired glucose metabolism), which relevantly contribute to the global care of a number of syndromic conditions. On the other hand, the presence of endocrine features may assist in the diagnostic process, leading to final diagnosis of a syndromic disorder. The intention of this review is to provide a referenced overview of different genetic syndromes characterized by endocrine features, and to present a possible classification, based on whether the endocrinopathy or the syndrome is typically recognized first. Thus, the first part of the manuscript deals with the most common syndromes associated with endocrine dysfunctions, while the second part describes the conditions by which a syndrome is most frequently diagnosed after an endocrine finding. The aim is to provide a practical overview of the assessment of syndromic patients, so that they can be recognized and managed in an integrated, multidisciplinary fashion.

Overview of Genetically Determined Diseases/Multiple Endocrine Neoplasia Syndromes Predisposing to Endocrine Tumors

In this chapter, we present an overview of multiple endocrine neoplasia syndromes including their most important clinical and molecular features. Multiple endocrine neoplasia type 1 and 2 syndromes (MEN1 and MEN2) are discussed in detail. Syndromes that are presented in other chapters are only briefly mentioned. We discuss the relevance of germline gene alterations in apparently sporadic endocrine tumors, e.g., medullary thyroid cancer, primary hyperparathyroidism, and neuroendocrine tumors. McCune-Albright syndrome that only exists in non-hereditary, sporadic forms is also discussed in detail, as tumors of several endocrine organs can develop in the same individual.

Distinct Clinical and Pathological Features of Melorheostosis Associated With Somatic MAP2K1 Mutations

Melorheostosis is a rare hyperostotic disease of the long bones classically characterized by a "dripping candle-wax" radiographic appearance. We recently described somatic activating mutations in MAP2K1 as a cause of melorheostosis. Here, we report distinguishing characteristics of patients with MAP2K1-positive melorheostosis. Fifteen unrelated patients with radiographic appearance of melorheostosis underwent paired biopsies of affected and unaffected bone for whole-exome sequencing, histology, and cell culture. Eight patients with mutations in MAP2K1 in affected bone were compared to the seven MAP2K1-negative patients to identify distinguishing characteristics. Patients with MAP2K1-positive melorheostosis had a distinct phenotype with classic "dripping candle-wax" appearance on radiographs (p = 0.01), characteristic vascular lesions on skin overlying affected bone (p = 0.01), and higher prevalence of extraosseous mineralization and joint involvement (p = 0.04 for both). Melorheostotic bone from both MAP2K1-positive and MAP2K1-negative patients showed two zones of distinct morphology-an outer segment of parallel layers of primary lamellar bone and a deeper zone of intensely remodeled highly porous osteonal-like bone. Affected bone from MAP2K1-positive patients showed excessive osteoid (p = 0.0012), increased number of osteoblasts (p = 0.012) and osteoclasts (p = 0.04), and increased vascularity on histology in comparison to paired unaffected bone which was not seen in affected bone in most MAP2K1-negative patients. The identification of a distinct phenotype of patients with MAP2K1-positive melorheostosis demonstrates clinical and genetic heterogeneity among patients with the disease. Further studies are needed to better understand the underlying pathophysiology and associated skin findings. © 2018 American Society for Bone and Mineral Research.

The Rare Neurocutaneous Disorders: Update on Clinical, Molecular, and Neuroimaging Features

Phakomatoses, also known as neurocutaneous disorders, comprise a vast number of entities that predominantly affect structures originated from the ectoderm such as the central nervous system and the skin, but also the mesoderm, particularly the vascular system. Extensive literature exists about the most common phakomatoses, namely neurofibromatosis, tuberous sclerosis, von Hippel-Lindau and Sturge-Weber syndrome. However, recent developments in the understanding of the molecular underpinnings of less common phakomatoses have sparked interest in these disorders. In this article, we review the clinical features, current pathogenesis, and modern neuroimaging findings of melanophakomatoses, vascular phakomatoses, and other rare neurocutaneous syndromes that may also include tissue overgrowth or neoplastic predisposition.

The causes and consequences of pituitary gigantism

In the general population, height is determined by a complex interplay between genetic and environmental factors. Pituitary gigantism is a rare but very important subgroup of patients with excessive height, as it has an identifiable and clinically treatable cause. The disease is caused by chronic growth hormone and insulin-like growth factor 1 secretion from a pituitary somatotrope adenoma that forms before the closure of the epiphyses. If not controlled effectively, this hormonal hypersecretion could lead to extremely elevated final adult height. The past 10 years have seen marked advances in the understanding of pituitary gigantism, including the identification of genetic causes in ~50% of cases, such as mutations in the AIP gene or chromosome Xq26.3 duplications in X-linked acrogigantism syndrome. Pituitary gigantism has a male preponderance, and patients usually have large pituitary adenomas. The large tumour size, together with the young age of patients and frequent resistance to medical therapy, makes the management of pituitary gigantism complex. Early diagnosis and rapid referral for effective therapy appear to improve outcomes in patients with pituitary gigantism; therefore, a high level of clinical suspicion and efficient use of diagnostic resources is key to controlling overgrowth and preventing patients from reaching very elevated final adult heights.

Management of precocious puberty in girls with McCune-Albright syndrome using letrozole

Objective To evaluate the safety and efficacy of letrozole in girls with progressive precocious puberty (PP) associated with McCune-Albright syndrome (MAS). Design Monocentric retrospective cross-sectional and longitudinal study of consecutive patients. Patients Ten MAS patients treated at Peking Union Medical College Hospital between September 1999 and December 2017 were retrospectively reviewed; those with complications due to PP were followed. Results The mean age at letrozole initiation was 4.5 ± 2.6 years, while the mean duration of treatment was 3.3 ± 2.4 years. Letrozole was highly effective at decreasing the rate of skeletal maturation, with a significant decrease in the bone age-to-chronological age (BA/CA) ratio from 1.9 ± 1.1 pre-treatment to 1.5 ± 1.2 on letrozole treatment (P = 0.016). Moreover, growth velocity Z-scores declined from 0.41 ± 0.5 to -0.2 ± 0.31 with treatment (P < 0.001). Predicted adult height Z-scores increased significantly from -2.03 ± 2.33 at baseline to 1.13 ± 0.84 following treatment initiation (P = 0.029). Moreover, vaginal bleeding declined significantly on letrozole. Conclusions Our findings suggest that letrozole may be an effective therapy in some girls with MAS, as treatment results in improved BA/CA ratio, growth velocity and predicted adult height. Possible adverse effects include nettle rash.

Fibrous dysplasia for radiologists: beyond ground glass bone matrix

Fibrous dysplasia (FD) is a congenital disorder arising from sporadic mutation of the α-subunit of the Gs stimulatory protein. Osseous changes are characterised by the replacement and distortion of normal bone with poorly organised, structurally unsound, fibrous tissue. The disease process may be localised to a single or multiple bones. In McCune-Albright syndrome (MAS), fibrous dysplasia is associated with hyperfunction of endocrine organs and overproduction of melanin in the skin, while Mazabraud syndrome FD is associated with intramuscular myxomas. In radiology, FD is very often automatically associated with the term "ground glass matrix". However, FD is a complex disease, and knowledge of its unique pathogenesis and course are crucial to understanding imaging findings and potential complications. This article aims to not only summarise the spectrum of radiological findings of osseous and extra-osseous abnormalities associated with FD but also to highlight the pathological base of the disease evolution, corresponding imaging changes and complications based on the disease distribution. We also have provided current recommendations for clinical management and follow-up of patients with FD. TEACHING POINTS: • FD is often a part of complex disease, involving not only bone but also multiple other organs. • FD lesions are characterised by age-related histological, radiographical and clinical transformations. • Radiologists play a crucial role in the identification of osseous complications associated with FD. • The craniofacial form of the disease is the most common type of FD and the most difficult form to manage. • Patients with McCune-Albright syndrome may have different extra-skeletal abnormalities, which often require follow-up.

Phenotypic testicular abnormalities and pubertal development in boys with McCune-Albright syndrome

Aim of this survey is to review the few available literature data on pathophysiologic and clinical aspects of pubertal development in boys with McCune-Albright syndrome (MAS). On the basis of such analysis, we concluded that:

1) peripheral precocious puberty (PPP) is significantly more infrequent in boys than in girls; 2) the most common testicular abnormality at MAS presentation is macroorchidism, that may be either monolateral or bilateral; 3) macroorchidism is not always associated with clinical and biochemical evidence of PPP; 4) testicular microlothiasis is distinctly more frequent in boys with MAS than in those without MAS; 5) the available therapeutic schedules have to be adopted already at MAS presentation only in the cases with PPP.

Role of phosphate sensing in bone and mineral metabolism

Inorganic phosphate (P_i) is essential for signal transduction and cell metabolism, and is also an essential structural component of the extracellular matrix of the skeleton. P_i is sensed in bacteria and yeast at the plasma membrane, which activates intracellular signal transduction to control the expression of P_i transporters and other genes that control intracellular P_i levels. In multicellular organisms, P_i homeostasis must be maintained in the organism and at the cellular level, requiring an endocrine and metabolic P_i-sensing mechanism, about which little is currently known. This Review will discuss the metabolic effects of P_i, which are mediated by P_i transporters, inositol pyrophosphates and SYG1-Pho81-XPR1 (SPX)-domain proteins to maintain cellular phosphate homeostasis in the musculoskeletal system. In addition, we will discuss how P_i is sensed by the human body to regulate the production of fibroblast growth factor 23 (FGF23), parathyroid hormone and calcitriol to maintain serum levels of P_i in a narrow range. New findings on the crosstalk between iron and P_i homeostasis in the regulation of FGF23 expression will also be outlined. Mutations in components of these metabolic and endocrine phosphate sensors result in genetic disorders of phosphate homeostasis, cardiomyopathy and familial basal ganglial calcifications, highlighting the importance of this newly emerging area of research.

[Mazabraud and McCune-Albright syndromes in association : A case of two very rare orthopaedic tumour entities]

We report on a 47-year-old woman with unilateral fibrous dysplasia and three intramuscular masses. Medical imaging revealed possible intramuscular myxomas, so that the suspected diagnosis was Mazabraud syndrome. After biopsy, the suspected diagnosis was verified by histology and molecular pathology. Due to endocrine abnormalities in the patient's medical history, McCune-Albright syndrome has was also verified.

Detection of new potentially pathogenic mutations in two patients with primary pigmented nodular adrenocortical disease (PPNAD) - case reports with literature review

INTRODUCTION

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare form of ACTH-independent Cushing's syndrome (CS). Half of patients with PPNAD are sporadic cases and the other half familial.

MATERIAL AND METHODS

We present two patients with PPNAD confirmed by genetic analysis.

RESULTS

In both patients there were no abnormal findings on diagnostic imaging of both adrenals and heart. Patients underwent bilateral two-stage adrenalectomy. Histopathological examination confirmed PPNAD. Genetic testing showed the following mutations in the PRKAR1A gene coding for the regulatory subunit type 1A of the protein kinase A enzyme: c.125dupG (patient 1) and c.15dupT (patient 2). Both these defects lead to inactivation of the PRKAR1A protein and are consequently causative of PPNAD in these patients.

CONCLUSIONS

The novel mutations presented in this article are considered to be pathogenic for PPNAD.

Short stature and growth hormone deficiency: unexpected manifestations of McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a rare disease characterised by triad of monostotic or polyostotic fibrous dysplasia, café au-lait skin spots and a variety of endocrine disorders; precocious puberty (PP) being the most common presenting symptom in female patients. Hyperfunction endocrinopathies including hyperthyroidism, growth hormone excess and cortisol excess are typical presentations in MAS. We present a case of 21-year-old woman with clinical and radiological characteristics of MAS triad; she presented with short stature which was attributed to both growth hormone deficiency and PP. Growth hormone deficiency in MAS has not been reported in English medical literature.

Laugier-Hunziker syndrome in endocrine clinical practice

Laugier–Hunziker syndrome (LHS) is a rare, benign and acquired disorder characterized by hyperpigmentation of the oral cavity and lips along with longitudinal melanonychia. No underlying systemic abnormalities or malignant predisposition is associated with it. In everyday clinical practice, an endocrinologist encounters certain endocrine conditions (e.g. Addison’s disease, McCune–Albright syndrome) that present with, inter alia, mucocutaneous hyperpigmentation. Even though LHS is easily distinguished from endocrine entities mentioned earlier, diagnostic evaluation usually requires skilled and thorough practitioner. Since it is the diagnosis of exclusion, a number of systemic conditions must be ruled out prior to making the final diagnosis. However, its major differential diagnosis is primarily Peutz-Jeghers syndrome, which carries an increased risk of cancer. Here, we report a case of a young woman who was referred to the endocrinologist for diagnostic evaluation of dark-colored lesions of the oral cavity and nails. All performed laboratory tests were within reference range. Endoscopic gastrointestinal evaluation did not reveal neoplastic formations. Owing to an adult-onset, asymptomatic clinical course and negative diagnostic findings, we made a final diagnosis. In this case, target diagnostic evaluation notably reduced the need for additional expensive and invasive procedures and treatments.

Genetics of primary macronodular adrenal hyperplasia

Recent advances in molecular genetics investigations of primary macronodular adrenal hyperplasia (PMAH) have been providing new insights for the research on this issue. The cAMP-dependent pathway is physiologically triggered by ACTH and its receptor, MC2-R, in adrenocortical cells. Different mechanisms of this cascade may be altered in some functioning adrenal cortical disorders. Activating somatic mutations of the GNAS gene (known as gsp oncogene) which encodes the stimulatory G protein alpha-subunit (Gsα) have been found in a small number of adrenocortical secreting adenomas and rarely in PMAH. Lately, ARMC5 was linked to the cyclic AMP signaling pathway, which could be implicated in all of mechanisms of cortisol-secreting by macronodules adrenal hyperplasia and the molecular defects in: G protein aberrant receptors; MC2R; GNAS; PRKAR1A; PDE11A; PDE8B. Around 50 % of patient's relatives with PMAH and 30 % of apparently sporadic hypercortisolism carried ARMC5 mutations. Therefore, PMAH is genetically determined more frequently than previously believed. This review summarizes the most important molecular mechanisms involved in PMAH.

Proteus Syndrome With a Cranial Intraosseous Lipoma

Intraosseous lipomas are almost exclusively seen in the long bones. Presence in the craniofacial skeleton is extremely rare. A 7-year-old male is presented with a marked craniofacial deformation from a bony tumor containing an intraosseous lipoma. This finding established a clinical diagnosis of Proteus syndrome. Given the size of the tumor, producing an extensive deformity, three-dimensional modeling was used to generate a three-dimensional printed implant. The process to achieve a successful outcome is herein described.

Fibrous dysplasia imitating malignancy

Fibrous dysplasia is a benign bone disease, presenting as monostotic or polyostotic lesions, or as part of a syndrome (McCune-Albright/Mazabraud). Its clinical course shows a variegated picture and the progression of its growth is unpredictable. In the workup of 39 fibrous dysplasia cases in the cranio-facial area, four cases presented fast growth tendencies, of which two patients with McCune-Albright syndrome showed malignant-like rapid growth. This local aggressive form is extremely rare, and the concept of this issue has not been clearly defined. With regard to the speed of growth a volumetric-time analysis in one of our cases demonstrated a 74 days tumor doubling rate with an exponential growth curve. According to the literature the aggressive form presented extra-cranially mainly at an adult age, whereas its appearance in our cranio-facial patient collective was much younger. Distinguishing nonmalignant and malignant aggressive forms is difficult and highly inconsistent in the literature. We therefore implemented a quantitative growth measure analysis to define aggressive forms based on progression and speed of growth and impartial of type of FD, localization or functional incapacity. Due to our study findings and literature review we state a prevalence of an aggressive form might be possibly about 5 %.

Treatment of precocious puberty in a McCune–Albright syndrome patient using Chinese medicinal herbs combined with megestrol acetate: A case report

Introduction: McCune–Albright Syndrome (MAS) is a rare congenital sporadic disorder characterized by fibrous bone dysplasia, café-au-lait pigmented spots on the skin, and non-gonadotropin dependent precocious puberty (PP), which is caused by a postzygotic somatic activating mutation in the GNAS gene encoding the alpha subunit of Gs protein. In our case study, we recorded a girl with the onset of MAS and treated her with Chinese medicinal herbs combined with megestrol acetate. We aim to provide a method for the treatment of children with this rare form of precocious puberty.

Case Presention: A 4-year-old girl presented with vaginal bleeding and enlarged breasts. The activating mutation of GNAS was not detected in the patient’s peripheral blood samples, as some had reported. Because of peripheral PP and fibrous dysplasia of the diagnosed bone, the patient was considered as MAS. We chose the Chinese medicinal herbs combined with megestrol acetate for treatment, and the patient was effectively treated.

Conclusion: The combination therapy of Chinese medicinal herbs plus megestrol acetate in managing PP in an MAS is one of the useful treatments.

Neonatal Cushing Syndrome: A Rare but Potentially Devastating Disease

Neonatal Cushing syndrome (CS) is most commonly caused by exogenous administration of glucocorticoids and rarely by endogenous hypercortisolemia. CS owing to adrenal lesions is the most common cause of endogenous CS in neonates and infants, and adrenocortical tumors (ACTs) represent most cases. Many ACTs develop in the context of a TP53 gene mutation, which causes Li-Fraumeni syndrome. More rarely, neonatal CS presents as part of other syndromes such as McCune-Albright syndrome or Beckwith-Wiedemann syndrome. Management usually includes resection of the primary tumor with or without additional medical treatment, but manifestations may persist after resolution of hypercortisolemia.

Polyostotic Fibrous Dysplasia With and Without McCune-Albright Syndrome-Clinical Features in a Nordic Pediatric Cohort

OBJECTIVE

Fibrous dysplasia (FD) presents as skeletal lesions in which normal bone is replaced by abnormal fibrous tissue due to mosaic GNAS mutation. McCune-Albright syndrome (MAS) refers to FD combined with skin (café-au-lait) and endocrine manifestations. This study describes the clinical childhood manifestations of polyostotic FD and MAS in a Nordic cohort.

PATIENTS AND DESIGN

We retrospectively reviewed a cohort of pediatric patients (n = 16) with polyostotic FD with or without MAS diagnosed and followed in two Nordic Pediatric tertiary clinics between 1996 and 2017.

RESULTS

Half of the 16 patients with polyostotic FD presented with MAS. All patients with MAS (n = 8) had café-au-lait spots, and either gonadotropin-independent precocious puberty (PP) (girls; n = 5) or abnormal testicle structure (boys, n = 3). None manifested hyperthyroidism or growth hormone excess. Mild hypophosphatemia was common (11/16), but none had signs of hypophosphatemic rickets. Craniofacial bone involvement was found in 12 patients (75%); in 5 of these, skeletal lesions were limited to craniofacial area. One child with craniofacial disease had lost vision due to optic nerve damage. Eleven (69%) patients had sustained a fracture at FD lesion, over half of them requiring surgical fixation of the fracture, most commonly in the proximal femur. The first symptoms leading to FD/MAS diagnosis included skull/facial asymmetry (n = 4), PP (n = 3), abnormal gait (n = 3), pathologic fracture (n = 3), wide-spread café-au-lait spots (n = 1), headache (n = 1), and vision loss (n = 1).

CONCLUSION

Polyostotic FD and MAS remain diagnostic and therapeutic challenges because of the broad clinical spectrum. Recurrent fractures, pain, and even vision loss may impair the quality of life in children with FD.

Peculiarities of Precocious Puberty in Boys and Girls With McCune-Albright Syndrome

McCune-Albright Syndrome (MAS; OMIM # 174800) is a rare, sporadic disease caused by a post-zygotic, activating mutation in the guanine-nucleotide binding protein α-subunit (GNAS1) gene. MAS is characterized by the clinical triad of polyostotic fibrous dysplasia of bone, café-au-lait skin pigmentation and peripheral precocious puberty. However, clinical presentation is highly variable depending on mosaic tissue distribution of mutant-bearing cells. Precocious puberty is the most common endocrine manifestation of MAS and is often the presenting, and sometimes the only, clinical sign of MAS. Due to the very low prevalence of MAS, data on course of precocious puberty, effectiveness of treatments and gonadal function during post-pubertal period are lacking. Our knowledge on this issue derives essentially from case reports and small cohorts of patients. The aim of this review is to report all available literature data on clinical aspects, therapeutic management and outcomes of precocious puberty in children with MAS. A systematic research was carried out through MEDLINE via PubMed, EMBASE, Web of Science, Semantic Scholar, Cochrane Library.

Detection of Rare Somatic GNAS Mutation in McCune-Albright Syndrome Using a Novel Peptide Nucleic Acid Probe in a Single Tube

McCune-Albright syndrome (MAS) is characterized by the triad of precocious puberty, café au lait pigmentation, and polyostotic fibrous dysplasia (FD) of bone, and is caused by post-zygotic somatic mutations-R201H or R201C-in the guanine nucleotide binding protein, alpha stimulating (GNAS) gene. In the present study, a novel peptide nucleic acid (PNA) probe with fluorescent labeling was designed to detect trace amounts of somatic mutant GNAS in a single tube reaction. The method was applied to screen GNAS mutations in six patients with MAS/FD. The results showed that the PNA probe assay could detect low abundant mutants in 200-fold excess of wild-type alleles. The GNAS mutation was found in three patients with severe disease (MAS) by using the assay. The other three patients with mild disease (having only FD) showed a wild-type result. This study has provided a simple method to detect trace amounts of GNAS mutants with high sensitivity in large amounts of wild-type DNA.

Acromegaly with hypophosphataemia: McCune-Albright syndrome

A 38-year-old man presented with excessive height gain and progressive enlargement of the extremities since childhood. This was compounded by lower limb deformities over the past 5 years. On examination, his height was 196 cm, he had macroglossia, acral enlargement, seborrhoea, hyperhidrosis-suggesting acrogigantism. He had facial asymmetry, wind-swept deformity of lower limbs and a café-au-lait macule over his trunk. Investigations revealed normal-sized pituitary gland with dysplastic cranial bones. Isotope bone scintigraphy was suggestive of polyostotic fibrous dysplasia. A diagnosis of McCune-Albright syndrome was made and trans-sphenoidal hypophysectomy was undertaken. He had persistent hypophosphataemia. Tubular reabsorption of phosphate adjusted for glomerular filtration rate was low and serum FGF-23 level was high. Ga-DOTATATE scintigraphy showed somatostatin-receptor expression in all the dysplastic lesions. FGF-23 produced by the bony lesions could counteract the phosphate-retaining effect of GH excess resulting in hypophosphataemia, which further worsened following hypophysectomy.

Post-traumatic fibrous dysplasia of the parietal bone: A rare entity

Fibrous dysplasia (FD) is a rare fibro-osseous lesion in which normal bone is replaced by abnormal fibrous tissue. Although a congenital disorder, a single case report of traumatic etiology had been described in the literature. We report a case of monostotic FD of the parietal calvarium in a 21-year-old female patient who presented to us with a single swelling in the parietal region been noticed after head injury sustained at the age of 7 years. After imaging investigations, the lesion was excised via craniotomy followed by cranioplasty in the same sitting. The histopathological evidence was suggestive of FD. To the best of our knowledge, this is the second case of a posttraumatic cranial FD and the first case describing the growing mass in the parietal bone secondary to head injury.

GNAS Mutations in Fibrous Dysplasia: A Comparative Study of Standard Sequencing and Locked Nucleic Acid PCR Sequencing on Decalcified and Nondecalcified Formalin-fixed Paraffin-embedded Tissues

It is well known that fibrous dysplasia (FD) is characterized by the presence of activating mutations involving G-nucleotide binding protein-α subunit (GNAS) involving codon R201 and rarely codon 227 with a mutation frequency between 45% and 93%. Herein, we investigate the sensitivity of detection of GNAS mutations in exons 8 and 9 using a standard and a highly sensitive locked nucleic acid polymerase chain reaction (LNA-PCR) sequencing in 52 cases of FD. In view of the recent report of GNAS mutations in a small number of low-grade osteosarcomas, we also tested in addition 12 cases of low-grade osteosarcomas. GNAS exon 8 mutations p.R201H (31%), p.R201C (15%), and p.R201S (2%) were identified in 50% of FD cases. LNA-PCR sequencing identified only 1 positive case within the mutation negative cases tested by standard PCR and Sanger sequencing. No mutations were identified in any of the low-grade osteosarcomas by standard and LNA-PCR sequencing. There was no association between age, site, size, specimen type, and mutational status. No exon 9 or codon 227 mutations were identified in any of tested cases. There was a significant difference in the sensitivity of the assay between decalcified and nondecalcified FDs (31% vs. 70%, P=0.002). LNA-PCR has no added value in enhancing detection sensitivity for GNAS mutations in FD. In addition to decalcification, innate somatic mosaicism contributes to the decreased sensitivity in mutation detection.

Mucinous Cystadenoma in Children and Adolescents

STUDY OBJECTIVE

Mucinous cystadenomas (MCAs) are benign epithelial ovarian tumors that occur rarely in children and adolescents. Because children and adolescents typically have their childbearing years ahead of them, conservative therapy is indicated. However, there is concern that ovarian cystectomy might be associated with significant recurrence risk in patients with MCA. Furthermore, guanine nucleotide binding protein, alpha stimulating (GNAS) gene mutations are associated with McCune-Albright syndrome, which is associated with cystic ovaries. We sought to evaluate the outcomes of children and adolescents with MCA treated conservatively. A subset of patients underwent GNAS gene testing.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS

After institutional board review approval, the pathology database of a large urban children's hospital was queried to identify adolescents with MCA between the years 2008 and 2014. Fourteen patients, aged 8-18 years (median, 14), were identified. A buccal swab for genetic testing was obtained from a subset of consenting patients.

MAIN OUTCOME MEASURES

MCA recurrence; ovarian return to normal size; GNAS gene variants.

RESULTS

Two patients underwent oophorectomies, and the remaining 12 underwent cystectomies. Follow-up ultrasound examination revealed slow return of ovary to normal size. Of the 10 patients with available follow-up data, there were no recurrences at a median of 225 days from surgery. Four patients consented to a buccal swab for genetic testing, and the GNAS gene was noted to have rare variants in 2 patients.

CONCLUSION

This series supports the use of ovary-sparing surgery in the treatment of MCA. Further research exploring possible genetic variants such as the GNAS gene in children and adolescents diagnosed with MCA is warranted.

Common mechanisms of catalysis in small and heterotrimeric GTPases and their respective GAPs

GTPases are central switches in cells. Their dysfunctions are involved in severe diseases. The small GTPase Ras regulates cell growth, differentiation and apoptosis by transmitting external signals to the nucleus. In one group of oncogenic mutations, the 'switch-off' reaction is inhibited, leading to persistent activation of the signaling pathway. The switch reaction is regulated by GTPase-activating proteins (GAPs), which catalyze GTP hydrolysis in Ras, and by guanine nucleotide exchange factors, which catalyze the exchange of GDP for GTP. Heterotrimeric G-proteins are activated by G-protein coupled receptors and are inactivated by GTP hydrolysis in the Gα subunit. Their GAPs are called regulators of G-protein signaling. In the same way that Ras serves as a prototype for small GTPases, Gαi1 is the most well-studied Gα subunit. By utilizing X-ray structural models, time-resolved infrared-difference spectroscopy, and biomolecular simulations, we elucidated the detailed molecular reaction mechanism of the GTP hydrolysis in Ras and Gαi1. In both proteins, the charge distribution of GTP is driven towards the transition state, and an arginine is precisely positioned to facilitate nucleophilic attack of water. In addition to these mechanistic details of GTP hydrolysis, Ras dimerization as an emerging factor in signal transduction is discussed in this review.

Rectal Metyrapone for Treatment of Hypercortisolism in an Infant with McCune-Albright Syndrome

Infantile Cushing syndrome is an infrequent yet potentially fatal manifestation of McCune-Albright syndrome, for which there are few safe treatments available. Ketoconazole is limited by potential hepatotoxicity in this population. Metyrapone may be an effective treatment, but it may not be tolerated when given orally. An infant with McCune-Albright syndrome presented with severe Cushing syndrome. Oral metyrapone resulted in feeding refusal, and ketoconazole caused an increase in liver enzymes; however, she was successfully treated with metyrapone given rectally. The patient avoided a feeding tube, and her serum cortisol concentration was lowered to a safe level. Metyrapone given per rectum may be a safe and effective alternative to oral metyrapone in treating young children with Cushing syndrome.

Effect of Intranasal Calcitonin in a Patient with McCune-Albright Syndrome, Fibrous Dysplasia, and Refractory Bone Pain

McCune-Albright syndrome (MAS) is a rare disease defined by the triad of polyostotic fibrous dysplasia of bone, café-au-lait skin spots, and precocious puberty. No available treatment is effective in changing the course of fibrous dysplasia of bone, but symptomatic patients require therapeutic support to reduce bone pain and prevent fractures and deformities. We report the case of a 27-year-old woman with MAS and severe fibrous dysplasia. She was diagnosed with MAS at 4 years of age and, during follow-up, she had multiple pathological fractures and bone pain refractory to treatment with bisphosphonates, tricyclic antidepressants, and opioids. The pain was incapacitating and the patient required a wheelchair. Intranasal calcitonin was then started, and, 30 days later, the patient already showed significant improvement in pain severity at the affected sites. After 3 months, she was able to walk without assistance. No adverse effects were observed, nor were any significant changes in serum levels of calcium, phosphorus, and alkaline phosphatase. Calcitonin has a well-recognized analgesic effect on bone tissue. Despite the small number of studies involving patients with MAS, calcitonin may be considered a short-term therapeutic option in cases of severe and refractory bone pain.

Genetic Aspects of Pituitary Adenomas

Although most of pituitary adenomas are benign, they may cause significant burden to patients. Sporadic adenomas represent the vast majority of the cases, where recognized somatic mutations (eg, GNAS or USP8), as well as altered gene-expression profile often affecting cell cycle proteins have been identified. More rarely, germline mutations predisposing to pituitary adenomas -as part of a syndrome (eg, MEN1 or Carney complex), or isolated to the pituitary (AIP or GPR101) can be identified. These alterations influence the biological behavior, clinical presentations and therapeutic responses, and their full understanding helps to provide appropriate care for these patients.

Heterotrimeric G proteins in the control of parathyroid hormone actions

Parathyroid hormone (PTH) is a key regulator of skeletal physiology and calcium and phosphate homeostasis. It acts on bone and kidney to stimulate bone turnover, increase the circulating levels of 1,25 dihydroxyvitamin D and calcium and inhibit the reabsorption of phosphate from the glomerular filtrate. Dysregulated PTH actions contribute to or are the cause of several endocrine disorders. This calciotropic hormone exerts its actions via binding to the PTH/PTH-related peptide receptor (PTH1R), which couples to multiple heterotrimeric G proteins, including G_s and G_q/11 Genetic mutations affecting the activity or expression of the alpha-subunit of G_s, encoded by the GNAS complex locus, are responsible for several human diseases for which the clinical findings result, at least partly, from aberrant PTH signaling. Here, we review the bone and renal actions of PTH with respect to the different signaling pathways downstream of these G proteins, as well as the disorders caused by GNAS mutations.

Clinical characteristics and management of growth hormone excess in patients with McCune-Albright syndrome

OBJECTIVE

McCune-Albright syndrome (MAS) is a sporadic, postzygotic disease presenting with fibrous dysplasia, cafe-au-lait spots and multiple endocrinopathies. Growth hormone (GH) excess is an uncommon but potentially severe complication of MAS. This study aims to describe the clinical manifestations of GH excess in the context of MAS and analyze the responses of these patients to treatments.

DESIGN

Retrospective clinical study.

METHODS

Clinical data from 52 MAS patients were analyzed. Serum GH and IGF1 levels, as well as nadir GH levels after an oral glucose tolerance test and alkaline phosphatase (ALP) levels were determined before and after the treatment.

RESULTS

In total, 13 MAS patients (25%) had the complication of GH excess, including 10 males (76.9%). Among them, all had FD, and 6 patients had sphenoidal bone involvement. Visual deficits were present in 8 patients, and hearing deficits were present in 5. Olfactory dysfunction was observed in 3 patients. Evident pituitary adenomas were confirmed in 9 patients by MRI. These patients underwent surgery with or without pretreatment of long-acting somatostatin analogue octreotide, and 6 achieved complete remission. The serum ALP levels decreased significantly after treatment for GH excess.

CONCLUSIONS

MAS with GH excess is more common in male patients. GH excess can lead to more severe skeletal lesions in MAS patients involving more of the craniofacial bones. Complete trans-sphenoidal complete tumor excision with neuronavigational guidance is effective and could lower ALP levels. LAR is recommended as a preoperative treatment and when patients fail to achieve complete remission after surgery.

Prognostic Factors From an Epidemiologic Evaluation of Fibrous Dysplasia of Bone in a Modern Cohort: The FRANCEDYS Study

Fibrous dysplasia of bone (FD) is a rare genetic but sporadic bone disease that can be responsible for bone pain, fracture, and bone deformity. The prognosis may be difficult to establish because of the wide spectrum of disease severity. We have analyzed the data from the French National Reference center for FD. We have established a database from standardized medical records. We have made descriptive statistics of the various forms of FD and examined the prognostic factors by multivariable logistic regression analysis, with a parsimonious stepwise method. The primary outcome was a clinically relevant composite index combining bone pain (visual analogic scale >3) and/or incident fracture. In our modern cohort of 372 patients, the median age at diagnosis was 23 years. The revealing symptom (at a median age of 18 years) was bone pain in 44% of patients and a fracture in 9%, but the diagnosis was fortuitous in 25% of cases. Monostotic forms represented 58% of patients and polyostotic forms 42%. The femur was the most commonly affected bone (44% of patients), followed by the skull (38%). Twelve percent of patients had McCune-Albright syndrome (MAS). With a median duration of follow-up of 7 years among 211 patients, we observed an incidence of fracture of 17% and 51% of patients had no bone pain at the end of follow-up (with or without bisphosphonate therapy). In univariate analysis, younger age at diagnosis, renal phosphate wasting, a polyostotic form, prevalent fracture, and bisphosphonate use were significant predictors. In the multivariate model, the polyostotic form and bisphosphonate use remained significant predictors. In conclusion, in a national referral center for FD, one patient on follow-up out of six had incident fracture. A polyostotic form was the main risk factor of a poorer outcome. © 2016 American Society for Bone and Mineral Research.

Advances in diagnosis and management of familial pituitary adenomas

Familial pituitary adenomas account for approximately 5–8% of all pituitary adenomas. Besides the adenomas occurring as part of syndromic entities that group several endocrine or nonendocrine disorders (multiple endocrine neoplasia type 1 or 4, Carney complex and McCune–Albright syndrome), 2–3% of familial pituitary adenomas fit into the familial isolated pituitary adenomas (FIPA) syndrome, an autosomal dominant condition with incomplete penetrance. About 20% of FIPA cases are due to mutations in the AIP gene and have distinct clinical characteristics. Recent findings have isolated a new non-AIP FIPA syndrome called X-linked acrogigantism, resulting from a microduplication that always includes the GPR101 gene. These new advances in the field of pituitary disease are opening up a new challenging domain to both clinicians and researchers. This review will focus on these recent findings and their contribution to the diagnosis and the management of familial pituitary adenomas.

Screening for genetic causes of growth hormone hypersecretion

Growth hormone (GH) secreting pituitary tumors may be caused by genetic abnormalities in a variety of genes including AIP, MEN1, CDKN1B, and PRKAR1A. These can lead to GH secreting pituitary adenomas as an isolated occurrence (e.g. as aggressive sporadic adenomas or in familial isolated pituitary adenomas (FIPA)) or as part of syndromic conditions such as MEN1 or Carney complex. These tumors have more aggressive features than sporadic acromegaly, including a younger age at disease onset and larger tumor size, and they can be challenging to manage. In addition to mutations or deletions, copy number variation at the GPR101 locus may also lead to mixed GH and prolactin secreting pituitary adenomas in the setting of X-linked acrogigantism (X-LAG syndrome). In X-LAG syndrome and in McCune Albright syndrome, mosaicism for GPR101 duplications and activating GNAS1 mutations, respectively, contribute to the genetic pathogenesis. As only 5% of pituitary adenomas have a known cause, efficient deployment of genetic testing requires detailed knowledge of clinical characteristics and potential associated syndromic features in the patient and their family.

Skin manifestations of growth hormone-induced diseases

The human skin is a well-organized organ bearing different types of cells in a well-structured interference to each other including epidermal and follicular keratinocytes, sebocytes, melanocytes, dermal papilla cells and fibroblasts, endothelial cells, sweat gland cells as well as nerves. Several hormones act on different cell types of the skin, while it is also considered an endocrine organ secreting hormones that act at several sites of the organism. GH receptors are found in almost all cell types forming the skin, while IGF-1 receptors' expression is restricted to the epidermal keratinocytes. Both Growth Hormone (GH) excess, as in the case of Acromegaly in adults, or Gigantism in growing children, and GH deficiency states lead to skin manifestations. In case of GH excess the main dermatological findings are skin thickening, coarsening of facial features, acrochordons, puffy hands and feet, oily skin and hyperhidrosis, while GH deficiency, on the contrary, is characterized by thin, dry skin and disorder of normal sweating. Moreover, special disorders associated with GH excess may have specific characteristics, as is the case of café-au-lait spots in Neurofibromatosis, or big café-au-lait skin hyperpigmented regions with irregular margins, as is the case in McCune-Albright syndrome. Meticulous examination of the skin may therefore contribute to the final diagnosis in cases of GH-induced disorders.

Male fertility and skin diseases

Male fertility can be affected by a variety of organs diseases, including the skin. Several genodermatoses affect the skin and several other organs including the male reproductive system, commonly in the form of cryptorchidism and hypogonadism. The most relevant syndromes are associated with dyschromias, such as deSanctis-Cacchione, poikiloderma congenital, LEOPARD, and H syndrome; others with ichthyosis, such as Rud, and trichothiodystrophy; or a group of unrelated genodermatoses, such as ablepharon macrostomia, Coffin-Siris, Gorlin-Goltz, and Werner. Acquired skin diseases may also affect male fertility usually in the form of orchitis or epididymal obstruction or androgen antagonists. These include infections (leprosy and HIV), autoimmune (erythema nodosum leprosum), granulomatous (sarcoidosis, Langerhans cell histiocytosis), nutritional deficiency (zinc), and malignancy. Several therapeutics of skin diseases are notorious for their effects on male fertility, most notably are the cytotoxic drugs (methotrexate), irradiation, and antiandrogens (spironolactone, finasteride). Although the prevalence of these skin diseases is low, the associated male infertility represents a challenge due to the difficulty of its management. Clinical management of the skin diseases should include consideration of their effects not only on the diseases but also on the male reproductive system.

Clinical and endocrine characteristics and genetic analysis of Korean children with McCune-Albright syndrome: a retrospective cohort study

Background

McCune–Albright syndrome (MAS) is a rare disease defined by the triad of fibrous dysplasia (FD), café au lait spots, and peripheral precocious puberty (PP). Because of the rarity of this disease, only a few individuals with MAS have been reported in Korea. We describe the various clinical and endocrine manifestations and genetic analysis of 14 patients with MAS in Korea.

Methods

Patients’ clinical data—including peripheral PP, FD, and other endocrine problems—were reviewed retrospectively. In addition, treatment experiences of letrozole in five patients with peripheral PP were described. Mutant enrichment with 3′-modified oligonucleotides - polymerase chain reaction (MEMO-PCR) was performed on eight patients to detect mutation in GNAS using blood. MEMO-PCR is a simple and practical method that enables the nondestructive selection and enrichment of minor mutant alleles in blood.

Results

The median age at diagnosis was 5 years 2 months (range: 18 months to 16 years). Eleven patients were female, and three were male. Thirteen patients showed FD. All female patients showed peripheral PP at onset, and three patients subsequently developed central PP. There was a significant decrease in estradiol levels after two years of letrozole treatment. However, bone age was advanced in four patients. Two patients had clinical hyperthyroidism, and two patients had growth hormone (GH) excess with pituitary microadenoma. c.602G > A (p.Arg201His) in GNAS was detected in two patients in blood, and c.601C > T (p.Arg201Cys) in GNAS was detected in one patient in pituitary adenoma.

Conclusions

This study described the various clinical manifestations of 14 patients with MAS in a single center in Korea. This study first applied MEMO-PCR on MAS patients to detect GNAS mutation. Because a broad spectrum of endocrine manifestations could be found in MAS, multiple endocrinopathies should be monitored in MAS patients. Better treatment options for peripheral PP with MAS are needed.

Rare diseases: matching wheelchair users with rare metabolic, neuromuscular or neurological disorders to electric powered indoor/outdoor wheelchairs (EPIOCs)

PURPOSE

To describe the clinical features of electric powered indoor/outdoor wheelchair (EPIOC) users with rare diseases (RD) impacting on EPIOC provision and seating.

METHOD

Retrospective review by a consultant in rehabilitation medicine of electronic and case note records of EPIOC recipients with RDs attending a specialist wheelchair service between June 2007 and September 2008. Data were systematically extracted, entered into a database and analysed under three themes; demographic, diagnostic/clinical (including comorbidity and associated clinical features (ACFs) of the illness/disability) and wheelchair factors.

RESULTS

Fifty-four (27 male) EPIOC users, mean age 37.3 (SD 18.6, range 11-70) with RDs were identified and reviewed a mean of 64 (range 0-131) months after receiving their wheelchair. Diagnoses included 27 types of RDs including Friedreich's ataxia, motor neurone disease, osteogenesis imperfecta, arthrogryposis, cerebellar syndromes and others. Nineteen users had between them 36 comorbidities and 30 users had 44 ACFs likely to influence the prescription. Tilt-in-space was provided to 34 (63%) users and specialised seating to 17 (31%). Four users had between them complex control or interfacing issues.

CONCLUSIONS

The complex and diverse clinical problems of those with RDs present unique challenges to the multiprofessional wheelchair team to maintain successful independent mobility and community living. Implications for Rehabilitation Powered mobility is a major therapeutic tool for those with rare diseases enhancing independence, participation, reducing pain and other clinical features. The challenge for rehabilitation professionals is reconciling the physical disabilities with the individual's need for function and participation whilst allowing for disease progression and/or growth. Powered wheelchair users with rare diseases with a (kypho) scoliosis require a wheelchair system that balances spine stability and movement to maximise residual upper limb and trunk function. The role of specialised seating needs careful consideration in supporting joint derangements and preventing complications such as pressure sores.

Tamoxifen Improves Final Height Prediction in Girls with McCune-Albright Syndrome: A Long Follow-Up

BACKGROUND

McCune-Albright syndrome (MAS) is a genetic disorder characterized by the triad of fibrous dysplasia, skin hyperpigmentation, and autonomous hyperfunction of various endocrine organs. MAS frequently presents in females as precocious puberty (PP). Although many treatments have been proposed, the preservation of final height (FH) in these patients remains a challenge.

OBJECTIVES

To evaluate the efficacy of tamoxifen in improving the FH prediction (FHP) in patients with MAS.

METHOD

We retrospectively analyzed 8 female patients with MAS who presented with café-au-lait spots and gonadotropin-independent PP. The patients were followed for a mean period of 8.3 years (range: 3-16).

RESULTS

All patients were treated with tamoxifen (10-20 mg/day) for 3-8 years (mean ± SD: 5.75 ± 2.05), which resulted in the cessation of vaginal bleeding and the stabilization of bone age maturation. There was a significant difference between the FHP at the beginning of treatment and at the end of treatment (145.1 ± 8.6 cm; Z score -2.84 ± 1.44 cm) and at the last evaluation (157.0 ± 9.2 cm; Z score -0.85 ± 0.54 cm; p < 0.001).

CONCLUSION

Our results support a role for tamoxifen in improving the FHP in patients with MAS.

Prevalence of Café-au-Lait Spots in children with solid tumors

Cafe-au-lait maculae (CALM) are frequently observed in humans, and usually are present as a solitary spot. Multiple CALMs are present in a smaller fraction of the population and are usually associated with other congenital anomalies as part of many syndromes. Most of these syndromes carry an increased risk of cancer development. Previous studies have indicated that minor congenital anomalies may be more prevalent in children with cancer. We investigated the prevalence of CALMs in two samples of Brazilian patients with childhood solid tumors, totaling 307 individuals. Additionally, 176 school children without diagnosis of cancer, or of a cancer predisposing syndrome, were investigated for the presence of CALMs. The prevalence of solitary CALM was similar in both study groups (18% and 19%) and also in the group of children without cancer. Multiple CALMs were more frequently observed in one of the study groups (Z = 2.1). However, when both groups were analyzed together, the significance disappeared (Z = 1.5). The additional morphological abnormalities in children with multiple CALMs were analyzed and compared to the findings observed in the literature. The nosologic entities associated with CALMs are reviewed.

Endoscopic Endonasal Optic Nerve Decompression for Fibrous Dysplasia

Objective To evaluate visual outcomes and potential complications for optic nerve decompression using an endoscopic endonasal approach (EEA) for fibrous dysplasia. Design Retrospective chart review of patients with fibrous dysplasia causing extrinsic compression of the canalicular segment of the optic nerve that underwent an endoscopic endonasal optic nerve decompression at the University of Pittsburgh Medical Center from 2010 to 2013. Main Outcome Measures The primary outcome measure assessed was best-corrected visual acuity (BCVA) with secondary outcomes, including visual field testing, color vision, and complications associated with the intervention. Results A total of four patients and five optic nerves were decompressed via an EEA. All patients were symptomatic preoperatively and had objective findings compatible with compressive optic neuropathy: decreased visual acuity was noted preoperatively in three patients while the remaining patient demonstrated an afferent pupillary defect. BCVA improved in all patients postoperatively. No major complications were identified. Conclusion EEA for optic nerve decompression appears to be a safe and effective treatment for patients with compressive optic neuropathy secondary to fibrous dysplasia. Further studies are required to identify selection criteria for an open versus an endoscopic approach.