Electronic reporting of rare endocrine conditions within a clinical network: results from the EuRRECa project

Objective

The European Registries for Rare Endocrine Conditions (EuRRECa, eurreb.eu) includes an e-reporting registry (e-REC) used to perform surveillance of conditions within the European Reference Network (ERN) for rare endocrine conditions (Endo-ERN). The aim of this study was to report the experience of e-REC over the 3.5 years since its launch in 2018.

Methods

Electronic reporting capturing new encounters of Endo-ERN conditions was performed monthly through a bespoke platform by clinicians registered to participate in e-REC from July 2018 to December 2021.

Results

The number of centres reporting on e-REC increased to a total of 61 centres from 22 countries. A median of 29 (range 11, 45) paediatric and 32 (14, 51) adult centres had reported cases monthly. A total of 9715 and 4243 new cases were reported in adults (age ≥18 years) and children, respectively. In children, sex development conditions comprised 40% of all reported conditions and transgender cases were most frequently reported, comprising 58% of sex development conditions. The median number of sex development cases reported per centre per month was 0.6 (0, 38). Amongst adults, pituitary conditions comprised 44% of reported conditions and pituitary adenomas (69% of cases) were most commonly reported. The median number of pituitary cases reported per centre per month was 4 (0.4, 33).

Conclusions

e-REC has gained increasing acceptability over the last 3.5 years for capturing brief information on new encounters of rare conditions and shows wide variations in the rate of presentation of these conditions to centres within a reference network. Significance statement Endocrinology includes a very wide range of rare conditions and their occurrence is often difficult to measure. By using an electronic platform that allowed monthly reporting of new clinical encounters of several rare endocrine conditions within a defined network that consisted of several reference centres in Europe, the EuRRECa project shows that a programme of e-surveillance is feasible and acceptable. The data that have been collected by the e-reporting of rare endocrine conditions (e-REC) can allow the continuous monitoring of rare conditions and may be used for clinical benchmarking, designing new studies or recruiting to clinical trials.

Evaluation of catch-up growth in severe pediatric Hashimoto's hypothyroidism

BACKGROUND

We aimed to evaluate catch-up growth in children with severe Hashimoto's hypothyroidism (HH) after thyroid hormone replacement therapy (HRT).

METHODS

A multicenter retrospective study was conducted including children referred for growth slowdown that led to the diagnosis of HH between 1998 and 2017.

RESULTS

A total of 29 patients were included, with a median age of 9.7 years (13-172 months). Median height at diagnosis was -2.7 [-4.6; -0.1] standard deviation score (SDS), with a height loss of 2.5 [0.7; 5.4] SDS compared to height before growth deflection (p<0.0001). At diagnosis, the median TSH level was 819.5 mIU/L [100; 1844], the median FT4 level was 0 pmol/L [undetectable; 5.4], and the median anti-thyroperoxidase antibody level was 1601 UI/L [47; 25,500]. In the 20 patients treated only with HRT, there were significant differences between height at diagnosis and height at 1 year (n = 19, p<0.0001), 2 years (n = 13, p = 0.0005), 3 years (n = 9, p = 0.0039), 4 years (n = 10, p = 0.0078), and 5 years (n = 10, p = 0.0018) of treatment but not in the case of final height (n = 6, p = 0.0625). Median final height was -1.4 [-2.7; 1,5] SDS (n = 6), with a significant difference between height loss at diagnosis and total catch-up growth (p = 0.003). The other nine patients were also given growth hormone (GH). They were smaller at diagnosis (p = 0.01); however, there was no difference in final height between those two groups (p = 0.68).

CONCLUSION

Severe HH can lead to a major height deficit, and catch-up growth seems to be insufficient after treatment with HRT alone. In the most severe cases, administration of GH may enhance this catch-up.

Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis

INTRODUCTION

Severe short stature is a feature of acrodysostosis, but data on growth are sparse. Treatment with recombinant human growth hormone (rhGH) is used in some centers to increase final height, but no studies have been published so far. Our objective was to conduct a multicenter, retrospective, cohort study to investigate growth in individuals with both types of acrodysostosis, treated with rhGH or not; we used the new nomenclature to describe acrodysostosis, as this disease belongs to the large group of inactivating PTH/PTHrP signaling disorders (iPPSD); acrodysostosis refers to iPPSD4 (acrodysostosis type 1 due to PRKAR1A mutations) and iPPSD5 (acrodysostosis type 2, due to PDE4D mutations).

METHODS

We present auxological data from individuals with genetically characterized iPPSD4, and participants with clinical features of iPPSD5.

RESULTS

We included 20 and 17 individuals with iPPSD4 and iPPSD5, respectively. The rhGH-treated iPPSD4 patients (n = 9) were smaller at birth than those who did not receive rhGH (median - 2.2 SDS vs. - 1.7 SDS); they showed a trend to catch-up growth during rhGH therapy (median 0.5 SDS in the first year). The rhGH-treated patients (n = 5) reached a better final height compared to those who did not receive rhGH (n = 4) (median - 2.8 SDS vs. - 3.9 SDS), suggesting that rhGH is efficient to increase height in those patients. The difference in target height to final height ranged between 1.6 and 3.0 SDS for iPPSD4 not treated with rhGH (n = 4), 2.1-2.8 SDS for rhGH-treated iPPSD4 (n = 5), 0.6-5.5 SDS for iPPSD5 not treated with rhGH (n = 5) and 2.5-3.1 for rhGH-treated iPPSD5 (n = 2).

CONCLUSION

Final height may be positively influenced by rhGH in patients with acrodysostosis/iPPSD. Our rhGH-treated cohort started therapy relatively late, which might explain, at least in part, the limited effect of rhGH on height.

"Baby-led weaning" - Progress in infant feeding or risky trend?

Baby-led weaning (BLW), proposed as a new form of complementary feeding, has emerged as a real trend phenomenon in the media. Infants are seated at the family table from the age of 6 months, facing the foods they grab and bring to their mouth: they decide which foods they want to eat and what amount. The consumption of mashed foods and the use of a spoon are totally discouraged. BLW is increasingly used in nurseries and centers of young children. A bibliographic search carried out between 2000 and 2021 found 423 articles, of which 38 were selected. The clinical studies selected are 11 cross-sectional observational studies and two randomized controlled studies. BLW promotes breastfeeding, the early introduction of morsels, the respect of the child's appetite, the use of unprocessed foods, and the choice of "homemade" and friendliness. These benefits can nonetheless be reached with usual complementary feeding (SCF), according to current recommendations. Other benefits are claimed without scientific evidence such as easier achievement of dietary complementary feeding and an optimal growth with prevention of excess weight gain. BLW has some obvious downsides. The infant may not get enough energy, iron, zinc, vitamins, and other nutrients, or too much protein, saturated fat, salt, or sugar. The risk of choking, which must be distinguished from the physiological gagging reflex, has not been ruled out by scientific studies. Currently, the Nutrition Committee of the French Pediatric Society considers that the data published to date in terms of benefits and risks of BLW do not lend themselves to advice for this practice in preference over SCF carried out according to current recommendations.

Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper

OBJECTIVES

Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations.

STUDY DESIGN

We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies.

RESULTS

We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations.

CONCLUSION

This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.

Human dentin characteristics of patients with osteogenesis imperfecta: insights into collagen-based biomaterials

Osteogenesis imperfecta (OI), also known as "brittle bone disease", is a rare genetic disorder of the skeleton, whose most benign form I corresponds to autosomal dominant mutations in the genes encoding type I collagen (COLA1, COLA2). Several associated skeletal manifestations are often observed but, surprisingly, while dentin defects often reflect genetic bone disorders, about half of OI patients have no obvious oral manifestations. Here, we investigated the collagen, mineral and mechanical properties of dentin from deciduous teeth collected from patients with mild form of OI and displaying no obvious clinical signs of dentinogenesis imperfecta. For the first time, an increase in the hardness of OI dentin associated with an increase in mineral content compared to healthy patients was reported. In addition, OI altered the tissue characteristics of the dentin-enamel junction but the interfacial gradient was preserved. The impact of changes in molecular structure due to mutations in OI was assessed by Raman microspectroscopy. Our results highlighted a change in the hydroxyproline-proline ratio in direct association with collagen mineralization. Our findings suggest that the evaluation of teeth could be an important aid for mild types of OI that are often difficult to diagnose clinically and provide experimental evidence that hydroxyproline content should be considered in future studies on collagen-based biomaterials.

Guidelines for the management of children at risk of secondary bone fragility: Expert opinion of a French working group

The current French national guidelines were elaborated by a working group consisting of experts in the field of pediatric endocrinology, rheumatology, hepatogastroenterology, nephrology, and pneumology. A systematic search was undertaken of the literature published between 2008 and 2018 and indexed in PubMed. The recommendations developed were then validated by an external evaluation group comprising representatives from the various highly specialized fields in pediatrics, representatives of the societies and groups supporting the development of the guidelines, and representatives of different healthcare professions. The objective of these guidelines was to detail the current optimal management of children at risk of secondary bone fragility.

Association of GNAS imprinting defects and deletions of chromosome 2 in two patients: clues explaining phenotypic heterogeneity in pseudohypoparathyroidism type 1B/iPPSD3

BACKGROUND

The term pseudohypoparathyroidism (PHP) describes disorders derived from resistance to the parathyroid hormone. Albright hereditary osteodystrophy (AHO) is a disorder with several physical features that can occur alone or in association with PHP. The subtype 1B, classically associated with resistance to PTH and TSH, derives from the epigenetic dysregulation of the GNAS locus. Patients showing features of AHO were described, but no explanation for such phenotypic heterogeneity is available. An AHO-like phenotype was associated with the loss of genetic information stored in chromosome 2q37, making this genomic region an interesting object of study as it could contain modifier genes involved in the development of AHO features in patients with GNAS imprinting defects. The present study aimed to screen a series of 65 patients affected with GNAS imprinting defects, with or without signs of AHO, for the presence of 2q37 deletions in order to find genes involved in the clinical variability.

RESULTS

The molecular investigations performed on our cohort of patients with GNAS imprinting defects identified two overlapping terminal deletions of the long arm of chromosome 2. The smaller deletion was of approximately 3 Mb and contained 38 genes, one or more of which is potentially involved in the clinical presentation. Patients with the deletions were both affected by a combination of the most pathognomic AHO-like features, brachydactyly, cognitive impairment and/or behavioural defects. Our results support the hypothesis that additional genetic factors besides GNAS methylation defects are involved in the development of a complex phenotype in the subgroup of patients showing signs of AHO.

CONCLUSIONS

For the first time, the present work describes PHP patients with hormone resistance and AHO signs simultaneously affected by GNAS imprinting defects and 2q37 deletions. Although further studies are needed to confirm the cause of these two rare molecular alterations and to identify candidate genes, this finding provides novel interesting clues for the identification of factors involved in the still unexplained clinical variability observed in PHP1B.

The current landscape of European registries for rare endocrine conditions

Objective To identify cross-border international registries for rare endocrine conditions that are led from Europe and to understand the extent of engagement with these registries within a network of reference centres (RCs) for rare endocrine conditions. Methods Database search of international registries and a survey of RCs in the European Reference Network for rare endocrine conditions (Endo-ERN) with an overall response rate of 82%. Results Of the 42 conditions with orphacodes currently covered within Endo-ERN, international registries exist for 32 (76%). Of 27 registries identified in the Orphanet and RD-Connect databases, Endo-ERN RCs were aware of 11 (41%). Of 21 registries identified by the RC, RD-Connect and Orphanet did not have a record of 10 (48%). Of the 29 glucose RCs, the awareness and participation rate in an international registry was highest for rare diabetes at 75 and 56% respectively. Of the 37 sex development RCs, the corresponding rates were highest for disorders of sex development at 70 and 52%. Of the 33 adrenal RCs, the rates were highest for adrenocortical tumours at 68 and 43%. Of the 43 pituitary RCs, the rates were highest for pituitary adenomas at 43 and 29%. Of the 31 genetic tumour RCs, the rates were highest for MEN1 at 26 and 9%. For the remaining conditions, awareness and participation in registries was less than 25%. Conclusion Although there is a need to develop new registries for rare endocrine conditions, there is a more immediate need to improve the awareness and participation in existing registries.

Hypocalcaemic and hypophosphatemic rickets

Rickets refers to deficient mineralization at the growth plate and is usually associated with abnormal serum calcium and/or phosphate. There are several subtypes of rickets, including hypophosphatemic rickets (vitamin-D-resistant rickets secondary to renal phosphate wasting), vitamin D-dependent rickets (defects of vitamin D metabolism) and nutritional rickets (caused by dietary deficiency of vitamin D, and/or calcium, and/or phosphate). Most rickets manifest as bone deformities, bone pain, and impaired growth velocity. Diagnosis of rickets is established through the medical history, physical examination, biochemical tests and radiographs. It is of crucial importance to determine the cause of rickets, including the molecular characterization in case of vitamin D resistant rickets, and initiate rapidly the appropriate therapy. In this review, we describe the different causes and therapies of genetic and nutritional rickets, supported by the recent progress in genetics and development of novel molecules such as anti-FGF23 antibody.

Long-term outcome of liver transplantation in childhood: A study of 20-year survivors

We report the results of a study of survival, liver and kidney functions, and growth with a median follow-up of 24 years following liver transplantation in childhood. From 1988 to 1993, 128 children underwent deceased donor liver transplantation (median age: 2.5 years). Twenty-year patient and graft survival rates were 79% and 64%, respectively. Raised serum aminotransferase and/or γ-glutamyl transferase activities were present in 42% of survivors after a single transplantation. Graft histology (35 patients) showed signs of chronic rejection in 11 and biliary obstruction in 5. Mean total fibrosis scores were 4.5/9 and 3/9 in patients with abnormal and normal serum liver tests, respectively. Glomerular filtration rate was <90 mL·min^-1 in 35 survivors, including 4 in end-stage renal disease who were undergoing dialysis or had undergone renal transplantation. Median final heights were 159 cm for women and 172 cm for men; final height was below the target height in 37 patients. Twenty-year survival after childhood liver transplantation may be close to 80%, and final height is within the normal range for most patients. However, chronic kidney disease or altered liver biochemistries are present in over one third of patients, which is a matter of concern for the future.

[Endocrine control of serum phosphate: from the discoveries of phosphatonins to novel therapies]

Phosphate is absorbed through the gut, stored in the bone and reabsorbed through the proximal renal tubule. More importantly, PTH and FGF23 have been identified as the main phosphaturic factors that control the expression of the phosphate co-transporters NaPi-IIa et IIc. By allowing the adjustment of the urinary phosphate reabsorption, these two phosphatonins play a major role in bone and tooth mineralization and growth. Recently, novel therapies have successfully targeted the FGF23 signaling pathway to treat the hypophosphatemia in patients affected with molecular defects of this pathway (mutations in the PHEX gene).

Outcomes of orthopedic surgery in a cohort of 49 patients with X-linked hypophosphatemic rickets (XLHR)

BACKGROUND

X-linked hypophosphatemic rickets (XLHR) is due to mutations in PHEX leading to unregulated production of FGF23 and hypophosphatemia. XLHR is characterized by leg bowing of variable severity. Phosphate supplements and oral vitamin analogs, partially or, in some cases, fully restore the limb straightness. Surgery is the alternative for severe or residual limb deformities.

OBJECTIVE

To retrospectively assess the results of surgical limb correction in XLHR (osteotomies and bone alignment except for 3 transient hemiepiphysiodesis).

METHODS

We analyzed the incidence of recurrence and post-surgical complications in 49 XLHR patients (29F, 20M) (mean age at diagnosis 6.0 years (± 7.1)).

RESULTS

At first surgery, the mean age was 13.4 years (± 5.0). Recurrence was observed in 14/49 (29%) patients. The number of additional operations significantly decreased with age (2.0 (± 0.9), 1.7 (± 1.0) and 1.2 (± 0.4) in children <11 years, between 11 and 15, and >15 years; P < 0.001). Incidence of recurrence seemed to be lower in patients with good metabolic control of the rickets (25% vs 33%). Complications were observed in 57% of patients.

CONCLUSION

We report a large series of surgical procedures in XLHR. Our results confirm that phosphate supplements and vitamin D analog therapy is the first line of treatment to correct leg bowing. Surgery before puberty is associated with a high risk of recurrence of the limb deformity. Such procedures should only be recommended, following multidisciplinary discussions, in patients with severe distortion leading to mechanical joint and ligament complications, or for residual deformities once growth plates have fused.

Defective Mineralization in X-Linked Hypophosphatemia Dental Pulp Cell Cultures

X-linked hypophosphatemia (XLH) is a skeletal disease caused by inactivating mutations in the PHEX gene. Mutated or absent PHEX protein/enzyme leads to a decreased serum phosphate level, which cause mineralization defects in the skeleton and teeth (osteomalacia/odontomalacia). It is not yet altogether clear whether these manifestations are caused solely by insufficient circulating phosphate availability for mineralization or also by a direct, local intrinsic effect caused by impaired PHEX activity. Here, we evaluated the local role of PHEX in a 3-dimensional model of extracellular matrix (ECM) mineralization. Dense collagen hydrogels were seeded either with human dental pulp cells from patients with characterized PHEX mutations or with sex- and age-matched healthy controls and cultured up to 24 d using osteogenic medium with standard phosphate concentration. Calcium quantification, micro-computed tomography, and histology with von Kossa staining for mineral showed significantly lower mineralization in XLH cell-seeded scaffolds, using nonparametric statistical tests. While apatitic mineralization was observed along collagen fibrils by electron microscopy in both groups, Raman microspectrometry indicated that XLH cells harboring the PHEX mutation produced less mineralized scaffolds having impaired mineral quality with less carbonate substitution and lower crystallinity. In the XLH cultures, immunoblotting revealed more abundant osteopontin (OPN), dentin matrix protein 1 (DMP1), and matrix extracellular phosphoglycoprotein (MEPE) than controls, as well as the presence of fragments of these proteins not found in controls, suggesting a role for PHEX in SIBLING protein degradation. Immunohistochemistry revealed altered OPN and DMP1 associated with an increased alkaline phosphatase staining in the XLH cultures. These results are consistent with impaired PHEX activity having local ECM effects in XLH. Future treatments for XLH should target both systemic and local manifestations.

Phosphate and Vitamin D Prevent Periodontitis in X-Linked Hypophosphatemia

X-linked hypophosphatemia (XLH) is a rare genetic skeletal disease where increased phosphate wasting in the kidney leads to hypophosphatemia and prevents normal mineralization of bone and dentin. Here, we examined the periodontal status of 34 adults with XLH and separated them according to the treatment they received for hypophosphatemia. We observed that periodontitis frequency and severity were increased in adults with XLH and that the severity varied according to the hypophosphatemia treatment. Patients who benefited from an early and continuous vitamin D and phosphate supplementation during their childhood presented less periodontal attachment loss than patients with late or incomplete supplementation. Continued hypophosphatemia treatment during adulthood further improved the periodontal health. Extracted teeth from patients with late or incomplete supplementation showed a strong acellular cementum hypoplasia when compared with age-matched healthy controls. These results show that XLH disturbs not only bone and dentin formation but also cementum and that the constitutional defect of the attachment apparatus is associated with attachment loss.

Recent Advances in Imprinting Disorders

Imprinting disorders (ImpDis) are a group of currently 12 congenital diseases with common underlying (epi)genetic etiologies and overlapping clinical features affecting growth, development and metabolism. In the last years it has emerged that ImpDis are characterized by the same types of mutations and epimutations, i.e. uniparental disomies, copy number variations, epimutations, and point mutations. Each ImpDis is associated with a specific imprinted locus, but the same imprinted region can be involved in different ImpDis. Additionally, even the same aberrant methylation patterns are observed in different phenotypes. As some ImpDis share clinical features, clinical diagnosis is difficult in some cases. The advances in molecular and clinical diagnosis of ImpDis help to circumvent these issues, and they are accompanied by an increasing understanding of the pathomechanism behind them. As these mechanisms have important roles for the etiology of other common conditions, the results in ImpDis research have a wider effect beyond the borders of ImpDis. For patients and their families, the growing knowledge contributes to a more directed genetic counseling of the families and personalized therapeutic approaches.

Adolescent spinal pain: The pediatric orthopedist's point of view

INTRODUCTION

Ten to twenty percent of persons experience spinal pain during growth. Causes are diverse in adolescents, and it is essential to determine etiology rapidly so as to guide optimal management.

HYPOTHESIS

It is important for the pediatric orthopedist to understand the natural history of conditions inducing spinal pain.

MATERIAL AND METHODS

A retrospective study included 116 adolescents presenting with spinal pain at the Hôpital Nord (Marseille, France) between January 1, 2009 and January 1, 2014. Malignant tumoral etiologies were excluded. Mean patient age was 13.6 years. Risser ranged between >0 and <5. Interview and clinical examination (skin, spine, neurologic examination, general clinical examination) were systematic; depending on results, complementary examinations (imaging, biology, biopsy) were prescribed.

RESULTS

There were 32 cases of non-specific adolescent low back pain, 31 of lumbar or thoracolumbar scoliosis, 23 of spinal growth dystrophy (Scheuermann's disease), 13 of isthmic lysis, 5 of spondylolisthesis, 8 of transitional lumbosacral hinge abnormality, 2 of discal hernia, 1 of osteoid osteoma and 1 of eosinophil granuloma. Treatment was often non-operative when diagnosis was sufficiently early. In case of failure, surgery could generally be considered.

DISCUSSION

Correctly indicated non-operative management or surgery changes the natural history of these pathologies. The aim of treatment is to resolve pain in adolescence, as it risks becoming chronic and disabling by adulthood.

Abnormal osteopontin and matrix extracellular phosphoglycoprotein localization, and odontoblast differentiation, in X-linked hypophosphatemic teeth

Mutations in phosphate-regulating gene (PHEX) lead to X-linked hypophosphatemic rickets (XLH), a genetic disease characterized by impaired mineralization in bones and teeth. In human XLH tooth dentin, calcospherites that would normally merge as part of the mineralization process are separated by unmineralized interglobular spaces where fragments of matrix proteins accumulate. Here, we immunolocalized osteopontin (OPN) in human XLH teeth, in a three-dimensional XLH human dental pulp stem cell-collagen scaffold culture model and in a rat tooth injury repair model treated with acidic serine- and aspartate-rich motif peptides (ASARM). In parallel, matrix extracellular phosphoglycoprotein (MEPE) immunolocalization and alkaline phosphatase (ALP) activity were assessed in XLH teeth. OPN was expressed by odontoblasts in the XLH models, and localized to the abnormal calcospherites of XLH tooth dentin. In addition, ALP activity and MEPE localization were abnormal in human XLH teeth, with MEPE showing an accumulation in the unmineralized interglobular spaces in dentin. Furthermore, XLH odontoblasts failed to form a well-polarized odontoblast layer. These data suggest that both MEPE and OPN are involved in impaired tooth mineralization associated with XLH, possibly through different effects on the mineralization process.

[Puberty, fertility and chronic diseases]

The onset of puberty is the sum of complex and multifactorial mechanisms resulting from the action of both activating and inhibiting factors, leading to the maturation of the gonads and the ability to reproduce. Many contributors to pubertal development are involved in fat mass acquisition and their action is relayed through the hypothalamus. It is therefore easy to understand how chronic diseases can affect the development of puberty and fertility apart from the specific impact of their molecular alteration. We have chosen cystic fibrosis and chronic renal disease as examples of chronic disorders affecting puberty through distinct mechanisms. As drugs are undistinguishable from chronic diseases, we also describe the impact of corticosteroids and chemotherapy on reproductive function. Last, we describe the surveillance and care of pubertal delay and its consequences (growth and bone mineralization) of patients affected with chronic disorders during adolescence.

Acrodysostosis

Acrodysostosis refers to a group of rare skeletal dysplasias that share in common characteristic clinical and radiological features including brachydactyly, facial dysostosis, and nasal hypoplasia. In the past, the term acrodysostosis has been used to describe patients with heterogeneous phenotypes, including, in some cases, patients that today would be given alternative diagnoses. The recent finding that mutations impairing the cAMP binding to PRKAR1A are associated with "typical" acrodysostosis and hormonal resistance initiates the era where this group of disorders can be categorized on a genetic basis. In this review, we will first discuss the clinical, radiologic, and metabolic features of acrodysostosis, emphasizing evidence that several forms of the disease are likely to exist. Second, we will describe recent results explaining the pathogenesis of acrodysostosis with hormonal resistance (ADOHR). Finally, we will discuss the similarities and differences observed comparing patients with ADOHR and other diseases resulting from defects in the PTHR1 signaling pathway, in particular, pseudohypoparathyroidism type 1a and pseudopseudohypoparathyroidism.

Tooth dentin defects reflect genetic disorders affecting bone mineralization

Several genetic disorders affecting bone mineralization may manifest during dentin mineralization. Dentin and bone are similar in several aspects, especially pertaining to the composition of the extracellular matrix (ECM) which is secreted by well-differentiated odontoblasts and osteoblasts, respectively. However, unlike bone, dentin is not remodelled and is not involved in the regulation of calcium and phosphate metabolism. In contrast to bone, teeth are accessible tissues with the shedding of deciduous teeth and the extractions of premolars and third molars for orthodontic treatment. The feasibility of obtaining dentin makes this a good model to study biomineralization in physiological and pathological conditions. In this review, we focus on two genetic diseases that disrupt both bone and dentin mineralization. Hypophosphatemic rickets is related to abnormal secretory proteins involved in the ECM organization of both bone and dentin, as well as in the calcium and phosphate metabolism. Osteogenesis imperfecta affects proteins involved in the local organization of the ECM. In addition, dentin examination permits evaluation of the effects of the systemic treatment prescribed to hypophosphatemic patients during growth. In conclusion, dentin constitutes a valuable tool for better understanding of the pathological processes affecting biomineralization.

Pineal cysts in children

OBJECTIVE: To describe the prevalence and characteristics of pineal cysts found on MRI in children. METHODS: This is a retrospective monocentric study of all brain magnetic resonance imaging (MRI) examinations performed under the same technical conditions for checking the idiopathic nature of short stature (ISS group, n = 116) and for the investigation of central precocious puberty (CPP) over a 3-year period (n = 56). Dimensions, wall and septal thickness, number of locules, signal intensity, and the presence of a solid component were analysed. Ten of 19 cysts were re-evaluated (follow-up interval 4-28 months). The prevalence of the pineal cysts was compared between the two groups using χ2 and Fisher's exact tests, and a significance threshold of p < 0.05. RESULTS: The prevalence of cysts was comparable in the two groups, CPP (10.7%) and ISS (11.2%). Cyst characteristics were similar in the two groups and 74% had thin septations. None of the cysts changed on follow-up. None of the children with pineal cysts exhibited neurological signs. CONCLUSION: Benign pineal cysts are a common finding in young children. High-resolution MRI demonstrates that these cysts are often septated. This pattern is a normal variant and does not require follow-up MR imaging or IV contrast media.

Growth hormone treatment before the age of 4 years prevents short stature in young girls with Turner syndrome

OBJECTIVE

Adult height deficit seen in Turner syndrome (TS) originates, in part, from growth retardation in utero and throughout the first 3 years of life. Earlier diagnosis enables earlier therapeutic intervention, such as with recombinant human GH (r-hGH), which may help to prevent growth retardation. In this open-label, multicentre phase III study, we investigated efficacy and safety in r-hGH treatment in young girls with TS.

SUBJECTS AND METHODS

Girls (n=61) aged <4 years with TS receiving 0.035-0.05 mg/kg per day r-hGH for 4 years were compared with an historical control group (n=51) comprising untreated, age- and height-matched girls with TS. The main outcome measure was change in height SDS (H-SDS). Other measures included changes in height velocity SDS, IGF1 levels and glucose metabolism.

RESULTS

After 4 years, a gain in mean H-SDS of 1.0 SDS (from -2.33±0.73 to -1.35±0.86 SDS) was observed with r-hGH treatment, in contrast to the decrease in mean H-SDS of 0.3 SDS in the control group (from -2.09±0.81 to -2.44±0.73 SDS; P<0.0001). r-hGH treatment was the main predictor of H-SDS gain and accounted for 52% of variability (multivariate analysis). r-hGH was well tolerated. As expected, IGF1 levels rose with treatment. A case of transient glucose intolerance resolved after dietary adaptation.

CONCLUSION

Early treatment with r-hGH helps to prevent natural evolution towards short stature in most girls with TS. IGF1 levels and glucose metabolism should be monitored routinely during r-hGH therapy.

[A peculiar form of neonatal adrenal insufficiency: the IMAGe association. Two new cases]

We report two siblings with an IMAGe syndrome. IMAGe is a newly reported syndrome characterized by the association of intra-uterine growth retardation, metaphyseal dysplasia, congenital adrenal hypoplasia and genital anomalies. This clinical association has only been described in five unrelated males. These two additional patients (one brother and one sister) suggest an autosomal recessive inheritance although identification of new cases will give further insight into the pathogenesis. The radiologic signs of osteopenia and metaphyseal dysplasia can suggest this diagnosis in affected individuals.

[Cushing's disease in children and adolescents]

Fifty-seven unselected children and adolescents with Cushing's disease underwent transsphenoidal exploration and microadenomectomy before their 16th birthday. Hypercortisolism was corrected in 42 of the 57 patients (74%). The recurrence rate was 17% and the long-term remission rate was 57%. Diagnostic peculiarities specific surgical problems and outcome were reviewed. Direct transnasal submucosal surgery for Cushing's disease is successful, and pituitary function can be preserved in most of these young patients.