Linear growth in children and adolescents with congenital adrenal hyperplasia.

PURPOSE OF REVIEW: Congenital adrenal hyperplasia (CAH) is a relatively common disorder and one of the most challenging conditions seen by pediatric endocrinologists. Poor linear growth in CAH has been recognized for many years. There are new insights to explain this abnormality and shed light on strategies to promote normal growth. RECENT FINDINGS: Published data suggest that the dose of hydrocortisone during two critical periods of rapid growth, namely infancy and at puberty, has a fundamental effect on growth velocity, and by definition adult height. To prevent over-treatment, hydrocortisone dosage should remain within the range of 10-15 mg/m2 body surface area per day. Precursor steroids such as 17-hydroxy progesterone (17OHP) should not be suppressed to undetectable levels. In fact, 17OHP should always be measurable, as complete suppression suggests over-treatment. SUMMARY: CAH is a challenging disorder. High-quality compliance within the consultation setting, with the patient seeing the same specialist at every visit, will be rewarded by improved long-term growth potential. Quality auxological monitoring can avoid phases of growth suppression. New therapy with CRH receptor antagonists may lead to a more nuanced approach by allowing fine tuning of hydrocortisone replacement without the need to suppress ACTH secretion.

Paediatric Cushing's disease: long-term outcome and predictors of recurrence.

Paediatric Cushing's disease (CD) is characterized by excess ACTH secretion from a pituitary adenoma, leading to hypercortisolism. It has approximately 5% of the incidence of adult CD and is a rare disorder in the paediatric age range. The four most specific presenting features of hypercortisolism are: change in facial appearance, weight gain, decreased linear growth and virilisation shown by advanced pubic hair for the stage of breast development or testicular volume. The main diagnostic priority is the demonstration of hypercortisolism followed by distinction between its ACTH-dependent and ACTH-independent origin, thus leading to identification of aetiology. All treatment options aim to resolve or control hypercortisolism. Consensus favours transsphenoidal (TSS) pituitary surgery with selective removal of the corticotroph adenoma. TSS in children with CD is now well established and induces remission in 70-100% of cases. External pituitary radiotherapy and bilateral adrenalectomy are second-line therapeutic approaches in subjects not responding to TSS. Long-term medical treatment is less frequently adopted. Recurrence in paediatric CD cases is low with factors predicting relapse being higher post-TSS cortisol and ACTH levels and rapid recovery of the hypothalamic-pituitary-adrenal axis after TSS. In summary, complete excision of the microadenoma with histological and biochemical evidence for this, predicts a low rate of recurrence of CD. Due to the need for rapid diagnosis and management to avoid the burden of prolonged exposure to hypercortisolism, tertiary university centres comprising both paediatric and adult endocrinology specialists together with experienced pituitary surgery and, eventually, radiotherapy units are recommended for referral of these patients.

Artificial intelligence in paediatric endocrinology: conflict or cooperation.

Artificial intelligence (AI) in medicine is transforming healthcare by automating system tasks, assisting in diagnostics, predicting patient outcomes and personalising patient care, founded on the ability to analyse vast datasets. In paediatric endocrinology, AI has been developed for diabetes, for insulin dose adjustment, detection of hypoglycaemia and retinopathy screening; bone age assessment and thyroid nodule screening; the identification of growth disorders; the diagnosis of precocious puberty; and the use of facial recognition algorithms in conditions such as Cushing syndrome, acromegaly, congenital adrenal hyperplasia and Turner syndrome. AI can also predict those most at risk from childhood obesity by stratifying future interventions to modify lifestyle. AI will facilitate personalised healthcare by integrating data from 'omics' analysis, lifestyle tracking, medical history, laboratory and imaging, therapy response and treatment adherence from multiple sources. As data acquisition and processing becomes fundamental, data privacy and protecting children's health data is crucial. Minimising algorithmic bias generated by AI analysis for rare conditions seen in paediatric endocrinology is an important determinant of AI validity in clinical practice. AI cannot create the patient-doctor relationship or assess the wider holistic determinants of care. Children have individual needs and vulnerabilities and are considered in the context of family relationships and dynamics. Importantly, whilst AI provides value through augmenting efficiency and accuracy, it must not be used to replace clinical skills.

Key Stages in the Development and Establishment of Paediatric Endocrinology: A Template for Future Progress.

BACKGROUND: Paediatric endocrinology became recognised in Western European countries in the 1960s and 1970s. It is now a thriving paediatric sub-speciality in many countries but remains non-existent or in its infancy in others. We have had the privilege to work in Western centres of excellence, and this review outlines the key stages in the development of modern centres, discussing the human and organisational issues that have underpinned progress in the establishment of this paediatric sub-speciality. SUMMARY: Human determination, vision, and ambition to create a modern centre and become a national flag bearer in the field are key components of success. The realisation that learning by spending time as a fellow away from one's home institution, so that knowledge can be acquired and brought back home, is also a key factor. Career structures should be designed to mentor and guide the trainee returning from a fellowship abroad. Scientific societies such as the European Society for Paediatric Endocrinology (ESPE) are key resources for networking, support, and discussion with experienced colleagues who may have faced similar challenges. Training and acquisition of knowledge through on-site or e-learning initiatives are beneficial and numerous examples exist, including the telemedicine model of store-and-forward consultations. Leadership skills can be learnt, and good working relationships with adult endocrinology colleagues result in benefits and political support. KEY MESSAGES: The development of paediatric endocrinology in a region with hitherto no such facilities constitutes a major contribution to local, regional, and, in all likelihood, national patient care.

Late-Onset Isolated Growth Hormone Deficiency.

Two male patients, who presented at 13.5 and 13.9 years of age with growth failure and short stature, were ultimately diagnosed with isolated growth hormone deficiency (GHD). Patient 1 was first evaluated when his height declined from -0.67 SD to -1.3 SD. He had a peak growth hormone (GH) concentration to GH stimulation test (GHST) of 16.9 ng/mL (16.9 µg/L) and remained untreated. As puberty advanced, his height decreased further to -1.65 SD. A second GHST while his serum testosterone was 79 ng/dL (2.74 nmol/L) had a peak GH of 5.4 ng/mL (5.4 µg/L), consistent with GHD. He was treated with GH for 4.8 years and reached adult height of 180.5 cm (0.57 SD), gaining 2.22 SDS. Patient 2, height -2.63 SD, had an unstimulated peak GH concentration of 19 ng/mL (19 µg/L). As puberty advanced, his height decreased further to -2.96 SD. Repeat peak GH concentration was 9.2 ng/mL (9.2 µg/L) when serum testosterone was 83.9 ng/dL (2.91 nmol/L). GH treatment resulted in rapid increase of height velocity from 1.8 cm/year to 11.3 cm/year in 6 months, consistent with GHD. Both patients demonstrate that GHD may develop over time and cannot be excluded by a single GHST. Longitudinal monitoring of children with poor growth as puberty progresses is essential to uncover GHD.

Rare forms of genetic paediatric adrenal insufficiency: Excluding congenital adrenal hyperplasia.

Adrenal insufficiency (AI) is a severe endocrine disorder characterized by insufficient glucocorticoid (GC) and/or mineralocorticoid (MC) secretion by the adrenal glands, due to impaired adrenal function (primary adrenal insufficiency, PAI) or to insufficient adrenal stimulation by pituitary ACTH (secondary adrenal insufficiency, SAI) or tertiary adrenal insufficiency due to hypothalamic dysfunction. In this review, we describe rare genetic causes of PAI with isolated GC or combined GC and MC deficiencies and we also describe rare syndromes of isolated MC deficiency. In children, the most frequent cause of PAI is congenital adrenal hyperplasia (CAH), a group of adrenal disorders related to steroidogenic enzyme deficiencies, which will not be included in this review. Less frequently, several rare diseases can cause PAI, either affecting exclusively the adrenal glands or with systemic involvement. The diagnosis of these diseases is often challenging, due to the heterogeneity of their clinical presentation and to their rarity. Therefore, the current review aims to provide an overview on these rare genetic forms of paediatric PAI, offering a review of genetic and clinical features and a summary of diagnostic and therapeutic approaches, promoting awareness among practitioners, and favoring early diagnosis and optimal clinical management in suspect cases.

Evaluating the sensitivity and specificity of the UK and Dutch growth referral criteria in predicting the diagnosis of pathological short stature.

OBJECTIVE: The aim of this observational study was to evaluate the UK and Dutch referral criteria for short stature to determine their sensitivity and specificity in predicting pathological short stature. Adherence to the recommended panel of investigations was also assessed. STUDY DESIGN: Retrospective review of medical records to examine the auxological parameters, investigations and diagnosis of subjects referred to two paediatric endocrine clinics at the Royal London Children's Hospital between 2016 and 2021. We analysed: height SD score (HtSDS), height SDS minus target height SDS (Ht-THSDS) and height deflection SDS (HtDefSDS). The UK referral criteria were HtSDS <-2.7, Ht-THSDS >2.0 and HtDefSDS >1.3. The Dutch referral criteria were HtSDS <-2.0, Ht-THSDS >1.6 and HtDefSDS >1.0. RESULTS: Data were available for 143 subjects (72% males) with mean (range) age 8.7 years (0.5-19.9). HtSDS and Ht-THSDS were significantly lower in the pathological stature (n=66) versus the non-pathological stature (n=77) subjects (-2.67±0.82 vs -1.97±0.70; p<0.001 and -2.07±1.02 vs -1.06±0.99; p<0.001, respectively). The sensitivity and specificity to detect pathology was 41% and 83% for the UK criteria (HtSDS <-2.7) compared with 59% and 79% for the Dutch criteria (HtSDS <-2.0), 48% and 83% for UK criteria (Ht-THSDS <-2.0) compared with 74% and 72% for Dutch criteria (Ht-THSDS <-1.6) and 33% and 68% for UK criteria (HtDefSDS >1.3) compared with 44% and 63% for the Dutch criteria (HtDefSDS >1.0). On average, each patient had 88% of the recommended investigations, and 53% had all the recommended testing. New pathology was identified in 36% of subjects. CONCLUSIONS: In isolation, the UK auxological referral thresholds have limited sensitivity and specificity for pathological short stature. The combination of HtSDS and Ht-THSDS improved the sensitivity of UK criteria to detect pathology from 41% to 68%. Attention to the child's genetic height potential prior to referral can prevent unnecessary assessments.

Applying precision medicine to the diagnosis and management of endocrine disorders.

Precision medicine employs digital tools and knowledge of a patient's genetic makeup, environment and lifestyle to improve diagnostic accuracy and to develop individualised treatment and prevention strategies. Precision medicine has improved management in a number of disease areas, most notably in oncology, and it has the potential to positively impact others, including endocrine disorders. The accuracy of diagnosis in young patients with growth disorders can be improved by using biomarkers. Insulin-like growth factor I (IGF-I) is the most widely accepted biomarker of growth hormone secretion, but its predictive value for recombinant human growth hormone treatment response is modest and various factors can affect the accuracy of IGF-I measurements. These factors need to be taken into account when considering IGF-I as a component of precision medicine in the management of growth hormone deficiency. The use of genetic analyses can assist with diagnosis by confirming the aetiology, facilitate treatment decisions, guide counselling and allow prompt intervention in children with pubertal disorders, such as central precocious puberty and testotoxicosis. Precision medicine has also proven useful during the transition of young people with endocrine disorders from paediatric to adult services when patients are at heightened risk of dropping out from medical care. An understanding of the likelihood of ongoing GH deficiency, using tools such as MRI, detailed patient history and IGF-I levels, can assist in determining the need for continued recombinant human growth hormone treatment during the process of transitional care.

Adherence to r-hGH Therapy in Pediatric Growth Hormone Deficiency: Current Perspectives on How Patient-Generated Data Will Transform r-hGH Treatment Towards Integrated Care.

Pediatric growth hormone (GH) deficiency is a licensed indication for replacement therapy with recombinant human growth hormone (r-hGH). Treatment, consisting of daily subcutaneous injections, extends from the time of diagnosis until cessation of linear growth at completion of puberty. Suboptimal adherence to r-hGH therapy is common and has been well documented to substantially impair the growth response and achievement of the optimal goal which is attainment of adult height within the genetic target range. The causes of poor adherence are complex and include disease-, patient-, doctor-, and treatment-related factors. Interventions for suboptimal adherence are important for a long-term successful outcome and can include both face-to-face and digital strategies. Face-to-face interventions include behavioral change approaches such as motivational interviewing and non-judgmental assessment. Medical and nursing staff require training in these techniques. Digital solutions are rapidly advancing as evidenced by the electronic digital auto-injector device, easypod® (Merck Healthcare KGaA, Darmstadt, Germany), which uses the web-based easypod® connect platform allowing adherence data to be transmitted electronically to healthcare professionals (HCPs), who can then access GH treatment history, enhancing clinical decisions. Over the past 10 years, the multi-national Easypod® Connect Observational Study has reported high levels of adherence (>85%) from up to 40 countries. The easypod® connect system can be supported by a smartphone app, growlink™, which facilitates the interactions between the patients, their care team, and patient support services. HCPs are empowered by new digital techniques, however, the human-digital partnership remains essential for optimal growth management. The pediatric patient on r-hGH therapy will benefit from these innovations to enhance adherence and optimize long-term response.

Patients' Perception of the Use of the EasyPod™ Growth Hormone Injector Device and Impact on Injection Adherence: A Multi-Center Regional Study.

Objective: This study aimed to assess patient perceptions of the use of the EasyPod™ growth hormone delivery device and its association with compliance. Methods: This cross-sectional, multicenter study was conducted in six centers from three countries (United Arab Emirates, Oman, and Saudi Arabia,) between March 2020 and June 2020. Children and adolescents aged 3-18 years, diagnosed with growth disorders and receiving rhGH through the EasyPod™ device were enrolled. Patients and caregivers were given a pre-set questionnaire that evaluated patient satisfaction, preference for technical and personalized features, and device drawbacks. The results were analyzed using independent measures of analysis of variance to evaluate the association of higher satisfaction with device features and better compliance. Results: A total of 186 patients were enrolled in the study. Of these, 45.7% had GH deficiency. The mean age (±SD) of patients was 11.8 (±2.76) years; 117 (62.90%) were males. Average compliance was 87%. One hundred patients (53.76%) had injection compliance of ≥90%. Amongst these patients, 74%, 68%, and 77% top-scored (5/5) the technical features of hidden needle, skin sensor, and pre-set dosing, respectively, compared to top scores by 39%, 34%, and 51% patients in the <90% compliance group (p-value <0.05). Similarly, a statistically significant difference was observed between the groups (p-value <0.05) in the perception of the usefulness of the tracking features such as display of history of injected doses (78% vs. 47.7%), a reminder for medicine remaining (46% vs. 23.3%) and battery power indicator (48% vs. 20.9%). Personal screen messages were associated with higher compliance while the requirement to keep the device in the fridge was reported as the most inconvenient feature by 56% of patients in the higher compliance group as against 39.5% in the lower compliance group (p-value <0.05). There was no statistically significant difference in the intensity of pain reported in the two compliance groups. Conclusion: Our study showed that there is a statistically significant association between better perception of device features and higher compliance.

GH Resistance Is a Component of Idiopathic Short Stature: Implications for rhGH Therapy.

Idiopathic short stature (ISS) is a term used to describe a selection of short children for whom no precise aetiology has been identified. Molecular investigations have made notable discoveries in children with ISS, thus removing them from this category. However, many, if not the majority of children referred with short stature, are designated ISS. Our interest in defects of GH action, i.e. GH resistance, has led to a study of children with mild GH resistance, who we believe can be mis-categorised as ISS leading to potential inappropriate management. Approval of ISS by the FDA for hGH therapy has resulted in many short children receiving this treatment. The results are extremely variable. It is therefore important to correctly assess and investigate all ISS subjects in order to identify those with mild but unequivocal GH resistance, as in cases of PAPP-A2 deficiency. The correct identification of GH resistance defects will direct therapy towards rhIGF-I rather than rhGH. This example illustrates the importance of recognition of GH resistance among the very large number patients referred with short stature who are labelled as 'ISS'.

Digital Health for Supporting Precision Medicine in Pediatric Endocrine Disorders: Opportunities for Improved Patient Care.

Digitalization of healthcare delivery is rapidly fostering development of precision medicine. Multiple digital technologies, known as telehealth or eHealth tools, are guiding individualized diagnosis and treatment for patients, and can contribute significantly to the objectives of precision medicine. From a basis of "one-size-fits-all" healthcare, precision medicine provides a paradigm shift to deliver a more nuanced and personalized approach. Genomic medicine utilizing new technologies can provide precision analysis of causative mutations, with personalized understanding of mechanisms and effective therapy. Education is fundamental to the telehealth process, with artificial intelligence (AI) enhancing learning for healthcare professionals and empowering patients to contribute to their care. The Gulf Cooperation Council (GCC) region is rapidly implementing telehealth strategies at all levels and a workshop was convened to discuss aspirations of precision medicine in the context of pediatric endocrinology, including diabetes and growth disorders, with this paper based on those discussions. GCC regional investment in AI, bioinformatics and genomic medicine, is rapidly providing healthcare benefits. However, embracing precision medicine is presenting some major new design, installation and skills challenges. Genomic medicine is enabling precision and personalization of diagnosis and therapy of endocrine conditions. Digital education and communication tools in the field of endocrinology include chatbots, interactive robots and augmented reality. Obesity and diabetes are a major challenge in the GCC region and eHealth tools are increasingly being used for management of care. With regard to growth failure, digital technologies for growth hormone (GH) administration are being shown to enhance adherence and response outcomes. While technical innovations become more affordable with increasing adoption, we should be aware of sustainability, design and implementation costs, training of HCPs and prediction of overall healthcare benefits, which are essential for precision medicine to develop and for its objectives to be achieved.

Growth Hormone Receptor (GHR) 6Ω Pseudoexon Activation: a Novel Cause of Severe Growth Hormone Insensitivity.

CONTEXT: Severe forms of growth hormone insensitivity (GHI) are characterized by extreme short stature, dysmorphism, and metabolic anomalies. OBJECTIVE: This work aims to identify the genetic cause of growth failure in 3 "classical" GHI individuals. METHODS: A novel intronic growth hormone receptor gene (GHR) variant was identified, and in vitro splicing assays confirmed aberrant splicing. A 6Ω pseudoexon GHR vector and patient fibroblast analysis assessed the consequences of the novel pseudoexon inclusion and the impact on GHR function. RESULTS: We identified a novel homozygous intronic GHR variant (g.5:42700940T > G, c.618+836T > G), 44 bp downstream of the previously recognized intronic 6Ψ GHR pseudoexon mutation in the index patient. Two siblings also harbored the novel intronic 6Ω pseudoexon GHR variant in compound heterozygosity with the known GHR c.181C > T (R43X) mutation. In vitro splicing analysis confirmed inclusion of a 151-bp mutant 6Ω pseudoexon not identified in wild-type constructs. Inclusion of the 6Ω pseudoexon causes a frameshift resulting in a nonfunctional truncated GHR lacking the transmembrane and intracellular domains. The truncated 6Ω pseudoexon protein demonstrated extracellular accumulation and diminished activation of STAT5B signaling following GH stimulation. CONCLUSION: Novel GHR 6Ω pseudoexon inclusion results in loss of GHR function consistent with a severe GHI phenotype. This represents a novel mechanism of Laron syndrome and is the first deep intronic variant identified causing severe postnatal growth failure. The 2 kindreds originate from the same town in Campania, Southern Italy, implying common ancestry. Our findings highlight the importance of studying variation in deep intronic regions as a cause of monogenic disorders.

Growth Hormone Receptor (Ghr) 6ω Pseudoexon Activation: A Novel Cause Of Severe Growth Hormone Insensitivity (Ghi).

CONTEXT: Severe forms of Growth Hormone Insensitivity (GHI) are characterized by extreme short stature, dysmorphism and metabolic anomalies. OBJECTIVE: Identification of the genetic cause of growth failure in 3 'classical' GHI subjects. DESIGN: A novel intronic GHR variant was identified, and in vitro splicing assays confirmed aberrant splicing. A 6Ω pseudoexon GHR vector and patient fibroblast analysis assessed the consequences of the novel pseudoexon inclusion and the impact on GHR function. RESULTS: We identified a novel homozygous intronic GHR variant (g.5:42700940T>G, c.618 + 836T> G), 44bp downstream of the previously recognized intronic 6Ψ GHR pseudoexon mutation in the index patient. Two siblings also harbored the novel intronic 6Ω pseudoexon GHR variant in compound heterozygosity with the known GHR c.181C>T (R43X) mutation. In vitro splicing analysis confirmed inclusion of a 151bp mutant 6Ω pseudoexon not identified in wild-type constructs. Inclusion of the 6Ω pseudoexon causes a frameshift resulting in a non-functional truncated GHR lacking the transmembrane and intracellular domains. The truncated 6Ω pseudoexon protein demonstrated extracellular accumulation and diminished activation of STAT5B signaling following growth hormone stimulation. CONCLUSION: Novel GHR 6Ω pseudoexon inclusion results in loss of GHR function consistent with a severe GHI phenotype. This represents a novel mechanism of Laron syndrome and is the first deep intronic variant identified causing severe postnatal growth failure. The 2 kindreds originate from the same town in Campania, Southern Italy, implying common ancestry. Our findings highlight the importance of studying variation in deep intronic regions as a cause of monogenic disorders.

Genetic Characterization of Short Stature Patients With Overlapping Features of Growth Hormone Insensitivity Syndromes.

CONTEXT: Growth hormone insensitivity (GHI) in children is characterized by short stature, functional insulin-like growth factor (IGF)-I deficiency, and normal or elevated serum growth hormone (GH) concentrations. The clinical and genetic etiology of GHI is expanding. OBJECTIVE: We undertook genetic characterization of short stature patients referred with suspected GHI and features which overlapped with known GH-IGF-I axis defects. METHODS: Between 2008 and 2020, our center received 149 GHI referrals for genetic testing. Genetic analysis utilized a combination of candidate gene sequencing, whole exome sequencing, array comparative genomic hybridization, and a targeted whole genome short stature gene panel. RESULTS: Genetic diagnoses were identified in 80/149 subjects (54%) with 45/80 (56%) having known GH-IGF-I axis defects (GHR n = 40, IGFALS n = 4, IGFIR n = 1). The remaining 35/80 (44%) had diagnoses of 3M syndrome (n = 10) (OBSL1 n = 7, CUL7 n = 2, and CCDC8 n = 1), Noonan syndrome (n = 4) (PTPN11 n = 2, SOS1 n = 1, and SOS2 n = 1), Silver-Russell syndrome (n = 2) (loss of methylation on chromosome 11p15 and uniparental disomy for chromosome 7), Class 3-5 copy number variations (n = 10), and disorders not previously associated with GHI (n = 9) (Barth syndrome, autoimmune lymphoproliferative syndrome, microcephalic osteodysplastic primordial dwarfism type II, achondroplasia, glycogen storage disease type IXb, lysinuric protein intolerance, multiminicore disease, macrocephaly, alopecia, cutis laxa, and scoliosis syndrome, and Bloom syndrome). CONCLUSION: We report the wide range of diagnoses in 149 patients referred with suspected GHI, which emphasizes the need to recognize GHI as a spectrum of clinical entities in undiagnosed short stature patients. Detailed clinical and genetic assessment may identify a diagnosis and inform clinical management.

Digital technologies to improve the precision of paediatric growth disorder diagnosis and management.

Paediatric disorders of impaired linear growth are challenging to manage, in part because of delays in the identification of pathological short stature and subsequent referral and diagnosis, the requirement for long-term therapy, and frequent poor adherence to treatment, notably with human growth hormone (hGH). Digital health technologies hold promise for improving outcomes in paediatric growth disorders by supporting personalisation of care, from diagnosis to treatment and follow up. The value of automated systems in monitoring linear growth in children has been demonstrated in Finland, with findings that such a system is more effective than a traditional manual system for early diagnosis of abnormal growth. Artificial intelligence has potential to resolve problems of variability that may occur during analysis of growth information, and augmented reality systems have been developed that aim to educate patients and caregivers about growth disorders and their treatment (such as injection techniques for hGH administration). Adherence to hGH treatment is often suboptimal, which negatively impacts the achievement of physical and psychological benefits of the treatment. Personalisation of adherence support necessitates capturing individual patient adherence data; the use of technology to assist with this is exemplified by the use of an electronic injection device, which shares real-time recordings of the timing, date and dose of hGH delivered to the patient with the clinician, via web-based software. The use of an electronic device is associated with high levels of adherence to hGH treatment and improved growth outcomes. It can be anticipated that future technological advances, coupled with continued 'human interventions' from healthcare providers, will further improve management of paediatric growth disorders.

Growth failure: 'idiopathic' only after a detailed diagnostic evaluation.

The terms 'idiopathic short stature' (ISS) and 'small for gestational age' (SGA) were first used in the 1970s and 1980s. ISS described non-syndromic short children with undefined aetiology who did not have growth hormone (GH) deficiency, chromosomal defects, chronic illness, dysmorphic features or low birth weight. Despite originating in the pre-molecular era, ISS is still used as a diagnostic label today. The term 'SGA' was adopted by paediatric endocrinologists to describe children born with low birth weight and/or length, some of whom may experience lack of catch-up growth and present with short stature. GH treatment was approved by the FDA for short children born SGA in 2001, and by the EMA in 2003, and for the treatment of ISS in the US, but not Europe, in 2003. These approvals strengthened the terms 'SGA' and 'ISS' as clinical entities. While clinical and hormonal diagnostic techniques remain important, it is the emergence of genetic investigations that have led to numerous molecular discoveries in both ISS and SGA subjects. The primary message of this article is that the labels ISS and SGA are not definitive diagnoses. We propose that the three disciplines of clinical evaluation, hormonal investigation and genetic sequencing should have equal status in the hierarchy of short stature assessments and should complement each other to identify the true pathogenesis in poorly growing patients.

Paediatric Cushing's disease: Epidemiology, pathogenesis, clinical management and outcome.

Cushing's disease (CD) is rare in paediatric practice but requires prompt investigation, diagnosis and therapy to prevent long-term complications. Key presenting features are a change in facial appearance, weight gain, growth failure, virilization, disturbed puberty and psychological disturbance. Close consultation with an adult endocrinology department is recommended regarding diagnosis and therapy. The incidence of CD, a form of ACTH-dependent Cushing's syndrome (CS), is equal to approximately 5% of that seen in adults. The majority of ACTH-secreting adenomas are monoclonal and sporadic, although recent studies of pituitary tumours have shown links to several deubiquitination gene defects. Diagnosis requires confirmation of hypercortisolism followed by demonstration of ACTH-dependence. Identification of the corticotroph adenoma by pituitary MRI and/or bilateral inferior petrosal sampling for ACTH may contribute to localisation before pituitary surgery. Transsphenoidal surgery (TSS) with selective microadenomectomy is first-line therapy, followed by external pituitary irradiation if surgery is not curative. Medical therapy to suppress adrenal steroid synthesis is effective in the short-term and bilateral adrenalectomy should be considered in cases unfit for TSS or radiotherapy or when urgent remission is needed after unsuccessful surgery. TSS induces remission of hypercortisolism and improvement of symptoms in 70-100% of cases, particularly when performed by a surgeon with experience in children. Post-TSS complications include pituitary hormone deficiencies, sub-optimal catch-up growth, and persisting excess of BMI. Recurrence of hypercortisolism following remission is recognised but infrequent, being less common than in adult CD patients. With experienced specialist medical and surgical care, the overall prognosis is good. Early referral to an experienced endocrine centre is advised.