Safe and effective use of a hybrid closed-loop system from diagnosis in children under 18 months with type 1 diabetes.

The management of type 1 diabetes in infancy presents significant challenges. Hybrid closed loop systems have been shown to be effective in a research setting and are now available for clinical use. There are relatively little reported data regarding their safety and efficacy in a real world clinical setting. We report two cases of very young children diagnosed with type 1 diabetes at ages 18 (Case 1) and 7 months (Case 2), who were commenced on hybrid closed-loop insulin delivery using the CamAPS FX™ system from diagnosis. At diagnosis, total daily dose (TDD) was 6 and 3.3 units for Case 1 and 2, respectively. Closed loop was started during the inpatient stay and weekly follow up was provided via video call on discharge. Seven months from diagnosis, Case 1 has an HbA1C of 49 mmol/mol, 61% time in range (TIR, 3.9-10 mmol/L) with 2% time in hypoglycemia (<3.9 mmol/L) with no incidents of very low blood glucose (BG; <3 mmol/L, 54 mg/dL) over 6 months. Given the extremely small TDD of insulin in Case 2, we elected to use diluted insulin (insulin aspart injection, NovoLog, Novo Nordisk Inc., Plainsboro, NJ, Diluting Medium for NovoLog®). Six months from diagnosis, the estimated HbA1c is 50 mmol/mol, TIR 76% with 1% hypoglycemia and no incidents of very low BG (<3 mmol/L, 54 mg/dL) over 6 months. We conclude that the use hybrid closed-loop can be safe and effective from diagnosis in children under 2 years of age with type 1 diabetes.

Absence of the ER Cation Channel TMEM38B/TRIC-B Disrupts Intracellular Calcium Homeostasis and Dysregulates Collagen Synthesis in Recessive Osteogenesis Imperfecta.

Recessive osteogenesis imperfecta (OI) is caused by defects in proteins involved in post-translational interactions with type I collagen. Recently, a novel form of moderately severe OI caused by null mutations in TMEM38B was identified. TMEM38B encodes the ER membrane monovalent cation channel, TRIC-B, proposed to counterbalance IP3R-mediated Ca2+ release from intracellular stores. The molecular mechanisms by which TMEM38B mutations cause OI are unknown. We identified 3 probands with recessive defects in TMEM38B. TRIC-B protein is undetectable in proband fibroblasts and osteoblasts, although reduced TMEM38B transcripts are present. TRIC-B deficiency causes impaired release of ER luminal Ca2+, associated with deficient store-operated calcium entry, although SERCA and IP3R have normal stability. Notably, steady state ER Ca2+ is unchanged in TRIC-B deficiency, supporting a role for TRIC-B in the kinetics of ER calcium depletion and recovery. The disturbed Ca2+ flux causes ER stress and increased BiP, and dysregulates synthesis of proband type I collagen at multiple steps. Collagen helical lysine hydroxylation is reduced, while telopeptide hydroxylation is increased, despite increased LH1 and decreased Ca2+-dependent FKBP65, respectively. Although PDI levels are maintained, procollagen chain assembly is delayed in proband cells. The resulting misfolded collagen is substantially retained in TRIC-B null cells, consistent with a 50-70% reduction in secreted collagen. Lower-stability forms of collagen that elude proteasomal degradation are not incorporated into extracellular matrix, which contains only normal stability collagen, resulting in matrix insufficiency. These data support a role for TRIC-B in intracellular Ca2+ homeostasis, and demonstrate that absence of TMEM38B causes OI by dysregulation of calcium flux kinetics in the ER, impacting multiple collagen-specific chaperones and modifying enzymes.

Karyotype - Phenotype Associations in Patients with Turner Syndrome.

Variation in karyotype may be associated with the phenotype of patients with Turner syndrome (TS). Our objective was to identify these associations between karyotype and phenotype in TS patients. This study was part of the European multicentre dsd-LIFE study. We evaluated the associations between different karyotypes of TS patients and age at diagnosis, Turner stigmata, cardiac/renal involvement and gonadal function. Information was available for 328 TS patients. Participants had a monosomy 45,X (46%), mosaicism 45,X/46,XX (10%), karyotype with isochromosome (18%), or other karyotype (26%). The clinical signs of TS were the most severe in patients with monosomy 45,X and the least severe in patients with mosaicism 45,X/46,XX. Patients with isochromosome and y-material showed an intermediate phenotype. Despite the more severe features in patients with monosomy 45,X, the median age at diagnosis was only slightly lower compared to patients with other karyotypes, which suggests opportunities for improvement of knowledge and diagnostics.

Phenotypic variability in patients with osteogenesis imperfecta caused by BMP1 mutations.

Osteogenesis Imperfecta (OI) is an inherited bone fragility disorder most commonly associated with autosomal dominant mutations in the type I collagen genes. Autosomal recessive mutations in a number of genes have also been described, including the BMP1 gene that encodes the mammalian Tolloid (mTLD) and its shorter isoform bone morphogenic protein-1 (BMP1). To date, less than 20 individuals with OI have been identified with BMP1 mutations, with skeletal phenotypes ranging from mild to severe and progressively deforming. In the majority of patients, bone fragility was associated with increased bone mineral density (BMD); however, the full range of phenotypes associated with BMP1 remains unclear. Here, we describe three children with mutations in BMP1 associated with a highly variable phenotype: a sibship homozygous for the c.2188delC mutation that affects only the shorter BMP1 isoform and a further patient who is compound heterozygous for a c.1293C>G nonsense mutation and a c.1148G>A missense mutation in the CUB1 domain. These individuals had recurrent fractures from early childhood, are hypermobile and have no evidence of dentinogenesis imperfecta. The homozygous siblings with OI had normal areal BMD by dual energy X-ray absorptiometry whereas the third patient presented with a high bone mass phenotype. Intravenous bisphosphonate therapy was started in all patients, but discontinued in two patients and reduced in another due to concerns about increasing bone stiffness leading to chalk-stick fractures. Given the association of BMP1-related OI with very high bone material density, concerns remain whether anti-resorptive therapy is indicated in this ultra-rare form of OI.© 2016 Wiley Periodicals, Inc.

ARNT2 mutation causes hypopituitarism, post-natal microcephaly, visual and renal anomalies.

We describe a previously unreported syndrome characterized by secondary (post-natal) microcephaly with fronto-temporal lobe hypoplasia, multiple pituitary hormone deficiency, seizures, severe visual impairment and abnormalities of the kidneys and urinary tract in a highly consanguineous family with six affected children. Homozygosity mapping and exome sequencing revealed a novel homozygous frameshift mutation in the basic helix-loop-helix transcription factor gene ARNT2 (c.1373_1374dupTC) in affected individuals. This mutation results in absence of detectable levels of ARNT2 transcript and protein from patient fibroblasts compared with controls, consistent with nonsense-mediated decay of the mutant transcript and loss of ARNT2 function. We also show expression of ARNT2 within the central nervous system, including the hypothalamus, as well as the renal tract during human embryonic development. The progressive neurological abnormalities, congenital hypopituitarism and post-retinal visual pathway dysfunction in affected individuals demonstrates for the first time the essential role of ARNT2 in the development of the hypothalamo-pituitary axis, post-natal brain growth, and visual and renal function in humans.

Effect of growth hormone deficiency on brain structure, motor function and cognition.

The growth hormone-insulin-like growth factor-1 axis plays a role in normal brain growth but little is known of the effect of growth hormone deficiency on brain structure. Children with isolated growth hormone deficiency (peak growth hormone <6.7 µg/l) and idiopathic short stature (peak growth hormone >10 µg/l) underwent cognitive assessment, diffusion tensor imaging and volumetric magnetic resonance imaging prior to commencing growth hormone treatment. Total brain, corpus callosal, hippocampal, thalamic and basal ganglia volumes were determined using Freesurfer. Fractional anisotropy (a marker of white matter structural integrity) images were aligned and tract-based spatial statistics performed. Fifteen children (mean 8.8 years of age) with isolated growth hormone deficiency [peak growth hormone <6.7 µg/l (mean 3.5 µg/l)] and 14 controls (mean 8.4 years of age) with idiopathic short stature [peak growth hormone >10 µg/l (mean 15 µg/l) and normal growth rate] were recruited. Compared with controls, children with isolated growth hormone deficiency had lower Full-Scale IQ (P < 0.01), Verbal Comprehension Index (P < 0.01), Processing Speed Index (P < 0.05) and Movement-Assessment Battery for Children (P < 0.008) scores. Verbal Comprehension Index scores correlated significantly with insulin-like growth factor-1 (P < 0.03) and insulin-like growth factor binding protein-3 (P < 0.02) standard deviation scores in isolated growth hormone deficiency. The splenium of the corpus callosum, left globus pallidum, thalamus and hippocampus (P < 0.01) were significantly smaller; and corticospinal tract (bilaterally; P < 0.045, P < 0.05) and corpus callosum (P < 0.05) fractional anisotropy were significantly lower in the isolated growth hormone deficiency group. Basal ganglia volumes and bilateral corticospinal tract fractional anisotropy correlated significantly with Movement-Assessment Battery for Children scores, and corpus callosum fractional anisotropy with Full-Scale IQ and Processing Speed Index. In patients with isolated growth hormone deficiency, white matter abnormalities in the corpus callosum and corticospinal tract, and reduced thalamic and globus pallidum volumes relate to deficits in cognitive function and motor performance. Follow-up studies that investigate the course of the structural and cognitive deficits on growth hormone treatment are now required to confirm that growth hormone deficiency impacts significantly on brain structure, cognitive function and motor performance.

Quality of Life in Men With Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency.

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is a disorder of adrenal steroid biosynthesis, leading to hypocortisolism, hypoaldosteronism, and hyperandrogenism. Impaired quality of life (QoL) has been demonstrated in women with CAH, but data on men with CAH are scarce. We hypothesized that disease severity and poor treatment control are inversely associated with QoL. In this study, 109 men (16-68 years) with 21OHD were included. The WHOQOL-BREF questionnaire was used to measure self-reported QoL domain scores on a 0-100 scale, where higher scores reflect better QoL. QoL domain scores were compared to published data on healthy and chronically ill reference populations from France, Germany, the Netherlands, and the United Kingdom. Differences in QoL scores among groups of disease severity and treatment control were tested within the study population. Overall, the men with CAH in this study appeared to rate their QoL as good. Median domain scores were 78.6 (IQR: 67.9-85.7) for physical health, 79.2 (IQR: 66.7-87.5) for psychological health, 75.0 (IQR: 58.3-83.3) for social relationships, and 81.3 (IQR: 71.9-90.6) for environment. In general, these scores were similar to WHOQOL-BREF domain scores in healthy references and higher compared to chronically ill reference populations. The domain scores did not differ among genotype groups, but patients with undertreatment or increased 17-hydroxyprogestrone concentrations scored higher on several QoL domains (p<0.05). Patients treated with dexamethasone or prednisone scored higher on the physical health, psychological health, and social relationships domains, but not on the environmental domain. In conclusion, QoL domain scores appeared to be comparable to healthy reference populations and higher compared to patients with a chronic illness. QoL was not influenced by genotype, but undertreatment and use of dexamethasone or prednisone were associated with higher QoL.

How close is the dose? Manipulation of 10 mg hydrocortisone tablets to provide appropriate doses to children.

This study explores the methodology advised by healthcare professionals and the methods used by parents/carers to identify whether there is a best practice method for manipulation of 10 mg hydrocortisone tablets to provide an accurate dose to children. Bespoke surveys were used to identify methods recommended and used in manipulation of tablets. Hydrocortisone tablets were manipulated to provide a specified dose by both naïve participants and parents/carers. The accuracy of manipulation was assessed using HPLC analysis. Competed surveys were received from 159 parent/carers reporting doses that ranged from 0.25 to 15 mg. Parents/carers most commonly reported splitting the tablet and administering the solid fraction; however more than 30% of those reporting physically splitting tablets were preparing doses that were not simply halving or quartering tablets. In a naïve population the dose accuracy, defined as percent of doses within 20% of the theoretical dose ranged from 57 to 58% depending on the tablet brand and the method of manipulation used. Almost three-quarters (74.1%) of parent/carers (n = 27) were able to produce a dose within 20% of the theoretical value and the most accurate method was to split tablets and administer the solid fraction. This study shows that a lack of age-appropriate medicines results in children being at risk of sub-optimal dosing.

Quantitative Brain MRI in Congenital Adrenal Hyperplasia: In Vivo Assessment of the Cognitive and Structural Impact of Steroid Hormones.

Context: Brain white matter hyperintensities are seen on routine clinical imaging in 46% of adults with congenital adrenal hyperplasia (CAH). The extent and functional relevance of these abnormalities have not been studied with quantitative magnetic resonance imaging (MRI) analysis. Objective: To examine white matter microstructure, neural volumes, and central nervous system (CNS) metabolites in CAH due to 21-hydroxylase deficiency (21OHD) and to determine whether identified abnormalities are associated with cognition, glucocorticoid, and androgen exposure. Design, Setting, and Participants: A cross-sectional study at a tertiary hospital including 19 women (18 to 50 years) with 21OHD and 19 age-matched healthy women. Main Outcome Measure: Recruits underwent cognitive assessment and brain imaging, including diffusion weighted imaging of white matter, T1-weighted volumetry, and magnetic resonance spectroscopy for neural metabolites. We evaluated white matter microstructure by using tract-based spatial statistics. We compared cognitive scores, neural volumes, and metabolites between groups and relationships between glucocorticoid exposure, MRI, and neurologic outcomes. Results: Patients with 21OHD had widespread reductions in white matter structural integrity, reduced volumes of right hippocampus, bilateral thalami, cerebellum, and brainstem, and reduced mesial temporal lobe total choline content. Working memory, processing speed, and digit span and matrix reasoning scores were reduced in patients with 21OHD, despite similar education and intelligence to controls. Patients with 21OHD exposed to higher glucocorticoid doses had greater abnormalities in white matter microstructure and cognitive performance. Conclusion: We demonstrate that 21OHD and current glucocorticoid replacement regimens have a profound impact on brain morphology and function. If reversible, these CNS markers are a potential target for treatment.

Cardiovascular health, growth and gonadal function in children and adolescents with congenital adrenal hyperplasia.

After the introduction of replacement therapy with glucocorticoids and mineralocorticoids in the 1950s, congenital adrenal hyperplasia (CAH) is no longer a life-limiting condition. However, due to the successful introduction of medical steroid hormone replacement, CAH has become a chronic condition, with associated comorbidities and long-term health implications. The aim of treatment is the replacement of mineralocorticoids and glucocorticoids and the normalisation of elevated androgen concentrations. Long-term consequences of the condition and current treatment regimens include unfavourable changes in the cardiovascular risk profile, impaired growth, testicular adrenal rest tumours (TART) in male and subfertility in both male and female patients with CAH. Optimising replacement therapy in patients with CAH remains challenging. On one hand, treatment with supraphysiological doses of glucocorticoids might be required to normalise androgen concentrations and decrease size or presence of TARTs. On the other hand, treatment with supraphysiological doses of glucocorticoids is associated with an increased prevalence of unfavourable cardiovascular and metabolic risk profiles as well as impaired longitudinal growth and gonadal function. Therefore, treatment of children and adults with CAH requires an individualised approach. Careful monitoring for early signs of complications is already warranted during paediatric healthcare provision to prevent and reduce the impact of comorbidities in later life.

Phenotypic Spectrum in Osteogenesis Imperfecta Due to Mutations in TMEM38B: Unraveling a Complex Cellular Defect.

Context: Recessive mutations in TMEM38B cause type XIV osteogenesis imperfecta (OI) by dysregulating intracellular calcium flux. Objectives: Clinical and bone material phenotype description and osteoblast differentiation studies. Design and Setting: Natural history study in pediatric research centers. Patients: Eight patients with type XIV OI. Main Outcome Measures: Clinical examinations included bone mineral density, radiographs, echocardiography, and muscle biopsy. Bone biopsy samples (n = 3) were analyzed using histomorphometry, quantitative backscattered electron microscopy, and Raman microspectroscopy. Cellular differentiation studies were performed on proband and control osteoblasts and normal murine osteoclasts. Results: Type XIV OI clinical phenotype ranges from asymptomatic to severe. Previously unreported features include vertebral fractures, periosteal cloaking, coxa vara, and extraskeletal features (muscular hypotonia, cardiac abnormalities). Proband lumbar spine bone density z score was reduced [median -3.3 (range -4.77 to +0.1; n = 7)] and increased by +1.7 (1.17 to 3.0; n = 3) following bisphosphonate therapy. TMEM38B mutant bone has reduced trabecular bone volume, osteoblast, and particularly osteoclast numbers, with >80% reduction in bone resorption. Bone matrix mineralization is normal and nanoporosity low. We demonstrate a complex osteoblast differentiation defect with decreased expression of early markers and increased expression of late and mineralization-related markers. Predominance of trimeric intracellular cation channel type B over type A expression in murine osteoclasts supports an intrinsic osteoclast defect underlying low bone turnover. Conclusions: OI type XIV has a bone histology, matrix mineralization, and osteoblast differentiation pattern that is distinct from OI with collagen defects. Probands are responsive to bisphosphonates and some show muscular and cardiovascular features possibly related to intracellular calcium flux abnormalities.

Current and novel approaches to children and young people with congenital adrenal hyperplasia and adrenal insufficiency.

Congenital adrenal hyperplasia (CAH) represents a group of autosomal recessive conditions leading to glucocorticoid deficiency. CAH is the most common cause of adrenal insufficiency (AI) in the paediatric population. The majority of the other forms of primary and secondary adrenal insufficiency are rare conditions. It is critical to establish the underlying aetiology of each specific condition as a wide range of additional health problems specific to the underlying disorder can be found. Following the introduction of life-saving glucocorticoid replacement sixty years ago, steroid hormone replacement regimes have been refined leading to significant reductions in glucocorticoid doses over the last two decades. These adjustments are made with the aim both of improving the current management of children and young persons and of reducing future health problems in adult life. However despite optimisation of existing glucocorticoid replacement regimens fail to mimic the physiologic circadian rhythm of glucocorticoid secretion, current efforts therefore focus on optimising replacement strategies. In addition, in recent years novel experimental therapies have been developed which target adrenal sex steroid synthesis in patients with CAH aiming to reduce co-morbidities associated with sex steroid excess. These developments will hopefully improve the health status and long-term outcomes in patients with congenital adrenal hyperplasia and adrenal insufficiency.

Reduced ventral cingulum integrity and increased behavioral problems in children with isolated optic nerve hypoplasia and mild to moderate or no visual impairment.

OBJECTIVES: To assess the prevalence of behavioral problems in children with isolated optic nerve hypoplasia, mild to moderate or no visual impairment, and no developmental delay. To identify white matter abnormalities that may provide neural correlates for any behavioral abnormalities identified. PATIENTS AND METHODS: Eleven children with isolated optic nerve hypoplasia (mean age 5.9 years) underwent behavioral assessment and brain diffusion tensor imaging, Twenty four controls with isolated short stature (mean age 6.4 years) underwent MRI, 11 of whom also completed behavioral assessments. Fractional anisotropy images were processed using tract-based spatial statistics. Partial correlation between ventral cingulum, corpus callosum and optic radiation fractional anisotropy, and child behavioral checklist scores (controlled for age at scan and sex) was performed. RESULTS: Children with optic nerve hypoplasia had significantly higher scores on the child behavioral checklist (p<0.05) than controls (4 had scores in the clinically significant range). Ventral cingulum, corpus callosum and optic radiation fractional anisotropy were significantly reduced in children with optic nerve hypoplasia. Right ventral cingulum fractional anisotropy correlated with total and externalising child behavioral checklist scores (r = -0.52, p<0.02, r = -0.46, p<0.049 respectively). There were no significant correlations between left ventral cingulum, corpus callosum or optic radiation fractional anisotropy and behavioral scores. CONCLUSIONS: Our findings suggest that children with optic nerve hypoplasia and mild to moderate or no visual impairment require behavioral assessment to determine the presence of clinically significant behavioral problems. Reduced structural integrity of the ventral cingulum correlated with behavioral scores, suggesting that these white matter abnormalities may be clinically significant. The presence of reduced fractional anisotropy in the optic radiations of children with mild to moderate or no visual impairment raises questions as to the pathogenesis of these changes which will need to be addressed by future studies.

Septo-optic dysplasia.

This review summarises the key clinical features of septo-optic dysplasia (SOD), the significant inroads that progress in genetics has made into our understanding of the aetiology of the condition over the last decade, and the pitfalls and challenges that we face in the management of these phenotypically variable patients.

Repetitive stimulation of the pituitary with growth-hormone-releasing hormone alters the proportion of 22 and 20 kilodalton human-growth hormone released.

Background/Aims. 20 Kilodalton-hGH (20 K-hGH) is the second most abundant pituitary GH variant after 22 K-hGH. In the steady state the proportion of 20 : 22 K-hGH appears constant; does this proportion change with repetitive somatotroph stimulation? Methods. Forty adult males were randomised to receive a GHRH(1-29)NH(2) bolus (0.5 mug/kg (n = 20) or 1.0 mug/kg (n = 20)), preceded or followed by a saline bolus, 1 week apart. Four to six weeks later, 10 subjects received 0.5 mug/kg GHRH(1-29)NH(2) at 0, 60, 120, and 180 minutes. Clearance rate of 22 and 20 K-hGH was measured in 10 subjects. Results. Total amount/proportion of 22 K-hGH/20 K-hGH secreted was similar for both GHRH(1-29)NH(2) doses. Repetitive stimulation reduced the amount of 22 K-hGH released whereas the amount of 20 K-hGH did not change significantly leading to an increase in the proportion of 20 K-hGH (P = .05). Half-life of 20 and 22 K-hGH were not significantly different (P = .55). Conclusions. Repetitive stimulation of the somatotroph may alter the proportion of GH variant released.