Missense variants are the most common type of coding genetic variants. Their functional assessment is fundamental for defining any implication in human diseases and may also uncover genes that are ...essential for human organ development. Here, we apply CRISPR-Cas9 gene editing on human iPSCs to study a heterozygous missense variant in GLI2 identified in two siblings with early-onset and insulin-dependent diabetes of unknown cause. GLI2 is a primary mediator of the Hedgehog pathway, which regulates pancreatic β-cell development in mice. However, neither mutations in GLI2 nor Hedgehog dysregulation have been reported as cause or predisposition to diabetes. We establish and study a set of isogenic iPSC lines harbouring the missense variant for their ability to differentiate into pancreatic β-like cells. Interestingly, iPSCs carrying the missense variant show altered GLI2 transcriptional activity and impaired differentiation of pancreatic progenitors into endocrine cells. RNASeq and network analyses unveil a crosstalk between Hedgehog and WNT pathways, with the dysregulation of non-canonical WNT signaling in pancreatic progenitors carrying the GLI2 missense variant. Collectively, our findings underscore an essential role for GLI2 in human endocrine development and identify a gene variant that may lead to diabetes.
Background
Given the limitations in the access and license status of commercially developed automated insulin delivery (AID) systems, open-source AID systems are becoming increasingly popular among ...people with diabetes, including children and adolescents.
Objective
This study aimed to investigate the lived experiences and physical and emotional health implications of children and their caregivers following the initiation of open-source AID, their perceived challenges, and sources of support, which have not been explored in the existing literature.
Methods
Data were collected through 2 sets of open-ended questions from a web-based multinational survey of 60 families from 16 countries. The narratives were thematically analyzed, and a coding framework was identified through iterative alignment.
Results
A range of emotions and improvements in quality of life and physical health were reported, as open-source AID enabled families to shift their focus away from diabetes therapy. Caregivers were less worried about hypoglycemia at night and outside their family homes, leading to increased autonomy for the child. Simultaneously, the glycemic outcomes and sleep quality of both the children and caregivers improved. Nonetheless, the acquisition of suitable hardware and technical setup could be challenging. The #WeAreNotWaiting community was the primary source of practical and emotional support.
Conclusions
Our findings show the benefits and transformative impact of open-source AID and peer support on children with diabetes and their caregivers and families, where commercial AID systems are not available or suitable. Further efforts are required to improve the effectiveness and usability and facilitate access for children with diabetes, worldwide, to benefit from this innovative treatment.
International Registered Report Identifier (IRRID)
RR2-10.2196/15368
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Zusammenfassung
Diabetes mellitus Typ 1 ist die häufigste endokrinologische Erkrankung bei Kindern und Jugendlichen unter 15 Jahren. Eine Heilungsperspektive bezüglich der Autoimmunreaktion gegen die ...insulinbildenden Betazellen ist weiterhin nicht in Sicht. Dennoch konnte durch technische Innovationsschübe bei Glukosesensoren, Insulinpumpen und Steuerungsalgorithmen innerhalb der letzten Jahre die Stoffwechselkontrolle optimiert werden. Diese Entwicklungen führen zusammen mit individuellen Diabetesschulungen und psychosozialer Unterstützung zu einer deutlichen Verbesserung der Versorgung.
In diesem Übersichtsartikel wird die aktuelle Versorgungssituation von Kindern und Jugendlichen mit Typ-1-Diabetes sowie ihren Eltern dargestellt. In Deutschland ist die multidisziplinäre, spezialisierte Versorgung durch Teams aus Kinder- und Jugenddiabetolog*innen, Diabetesberater*innen, Sozialarbeiter*innen und Kinder- und Jugendpsychotherapeut*innen seit vielen Jahren etabliert und führt zu einer im internationalen Vergleich sehr guten Versorgungsqualität. Fokussiert werden die Diabetesschulung mit dem Schwerpunkt, das Selbstmanagement optimal zu unterstützen, die psychosoziale Begleitung und Intervention sowie die Inklusion in Schulen und Kindertagesstätten. Wir gehen außerdem auf neue soziale Entwicklungen der Diabetes-Online-Community ein. Ein aktuelles Beispiel ist die patientenbetriebene Bewegung „Do-It-Yourself Artificial Pancreas System“ (DIY-APS), die als Open-Source-Projekt mittlerweile Innovationsgeber auch für Medizinproduktehersteller ist. Zum Schluss beleuchten wir die damit verbundenen Chancen, aber auch die Verschiebung der klassischen Arzt-Patienten-Rollen.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Introduction. Childhood obesity is increasing worldwide and presents as a global health issue due to multiple metabolic comorbidities. About 1% of adolescents with obesity develop type 2 diabetes ...(T2D); however, little is known about the genetic and pathophysiological background at young age. The objective of this study was to assess the prevalence of impaired glucose regulation (IGR) in a large cohort of children and adolescents with obesity and to characterize insulin sensitivity and insulin secretion. We also wanted to investigate adolescents with insulin secretion disorder more closely and analyze possible candidate genes of diabetes in a subcohort. Methods. We included children and adolescents with obesity who completed an oral glucose tolerance test (OGTT, glucose+insulin) in the outpatient clinic. We calculated Matsuda index, the area under the curve (AUC (Ins/Glu)), and an oral disposition index (ISSI-2) to estimate insulin resistance and beta-cell function. We identified patients with IGR and low insulin secretion (maximum insulin during OGTT<200 mU/l) and tested a subgroup using next generation sequencing to identify possible mutations in 103 candidate genes. Results. The total group consisted of 903 children and adolescents with obesity. 4.5% showed impaired fasting glucose, 9.4% impaired glucose tolerance, and 1.2% T2D. Matsuda index and Total AUC (Ins/Glu) showed a hyperbolic relationship. Out of 39 patients with low insulin secretion, we performed genetic testing on 12 patients. We found five monogenetic defects (ABCC8 (n=3), GCK (n=1), and GLI2/PTF1A (n=1)). Conclusion. Using surrogate parameters of beta-cell function and insulin resistance can help identify patients with insulin secretion disorder. A prevalence of 40% mutations of known diabetes genes in the subgroup with low insulin secretion suggests that at least 1.7% of patients with adolescent obesity have monogenic diabetes. A successful molecular genetic diagnosis can help to improve individual therapy.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Heterozygous coding mutations in the INS gene that encodes preproinsulin were recently shown to be an important cause of permanent neonatal diabetes. These dominantly acting mutations prevent normal ...folding of proinsulin, which leads to beta-cell death through endoplasmic reticulum stress and apoptosis. We now report 10 different recessive INS mutations in 15 probands with neonatal diabetes. Functional studies showed that recessive mutations resulted in diabetes because of decreased insulin biosynthesis through distinct mechanisms, including gene deletion, lack of the translation initiation signal, and altered mRNA stability because of the disruption of a polyadenylation signal. A subset of recessive mutations caused abnormal INS transcription, including the deletion of the C1 and E1 cis regulatory elements, or three different single base-pair substitutions in a CC dinucleotide sequence located between E1 and A1 elements. In keeping with an earlier and more severe beta-cell defect, patients with recessive INS mutations had a lower birth weight (-3.2 SD score vs. -2.0 SD score) and were diagnosed earlier (median 1 week vs. 10 weeks) compared to those with dominant INS mutations. Mutations in the insulin gene can therefore result in neonatal diabetes as a result of two contrasting pathogenic mechanisms. Moreover, the recessively inherited mutations provide a genetic demonstration of the essential role of multiple sequence elements that regulate the biosynthesis of insulin in man.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Two children with intrauterine growth retardation and short stature who had mutations in the gene for the insulin-like growth factor I receptor (
IGF-IR
) were identified among 51 children with short ...stature (most with intrauterine growth retardation) who were screened for these mutations. One child was a compound heterozygote for point mutations in exon 2, resulting in marked reductions in IGF-I–receptor binding. The other child had a nonsense mutation that reduced the number of cell-surface IGF-I receptors. No
IGF-IR
mutations were found in 43 controls with normal birth weights.
Uncommon causes of intrauterine and postnatal growth failure.
Insulin-like growth factors I (IGF-I) and II (IGF-II) are major regulators of somatic growth and cellular proliferation and act through a common receptor, the type I IGF receptor. The gene for the IGF-I receptor (
IGF-IR
) is homologous to the insulin receptor gene in terms of both exon and intron organization and its amino acid sequence (more than 50 percent identical).
1
Both encode precursor proteins that undergo post-translational modification to yield receptors composed of two α and two β subunits. The α subunits are extracellular, containing ligand-binding domains. The β subunits contain intracellular tyrosine kinase domains.
2
More than 50 . . .
Mutations in several genes cause nonautoimmune diabetes, but numerous patients still have unclear genetic defects, hampering our understanding of the development of the disease and preventing ...pathogenesis-oriented treatment. We used whole-genome sequencing with linkage analysis to study a consanguineous family with early-onset antibody-negative diabetes and identified a novel deletion in PCBD1 (pterin-4 α-carbinolamine dehydratase/dimerization cofactor of hepatocyte nuclear factor 1 α), a gene that was recently proposed as a likely cause of diabetes. A subsequent reevaluation of patients with mild neonatal hyperphenylalaninemia due to mutations in PCBD1 from the BIODEF database identified three additional patients who had developed HNF1A-like diabetes in puberty, indicating early β-cell failure. We found that Pcbd1 is expressed in the developing pancreas of both mouse and Xenopus embryos from early specification onward showing colocalization with insulin. Importantly, a morpholino-mediated knockdown in Xenopus revealed that pcbd1 activity is required for the proper establishment of early pancreatic fate within the endoderm. We provide the first genetic evidence that PCBD1 mutations can cause early-onset nonautoimmune diabetes with features similar to dominantly inherited HNF1A-diabetes. This condition responds to and can be treated with oral drugs instead of insulin, which is important clinical information for these patients. Finally, patients at risk can be detected through a newborn screening for phenylketonuria.
Objective This prospective longitudinal survey was designed to follow patients with diabetes from disease onset in childhood over an extended period of time including puberty until young adulthood ...with respect to metabolic control. Study design An electronic diabetes patient documentation system used in diabetes centers in Austria and Germany was utilized for standardized data collection. Complete documentation of metabolic control for prepuberty (≤13 years), puberty (14-19 years), and adulthood (≥20 years) was available in 1146 patients. Results Median age at diabetes manifestation was 7.2 (IQR 4.7-9.4) years; 49% were male. In the prepubertal stage, median glycated hemoglobin A1c (HbA1c) was 7.5 (IQR 6.8-8.3), during puberty 8.0 (IQR 7.3-8.9), and after puberty 7.8 (IQR 7.1-9.0). A significant intra-individual correlation was found for prepuberty to puberty HbA1c levels (R = 0.55, P < .001), puberty to adulthood (R = 0.59, P < .001), as well as prepuberty to adulthood (R = 0.30, P < .001). When patients were divided into tertiles of prepubertal HbA1c, HbA1c increased in all 3 groups over time, however, significant group differences tracked into adulthood ( P < .001 at all stages). A regression model identified pre-pubertal HbA1c as a significant and relevant predictor of metabolic control in young adulthood adjusted for confounders ( P < .001). Conclusions This survey provides evidence for long-term tracking of metabolic control from childhood until adulthood, suggesting an early focus on metabolic control.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aims: HNF1B-maturity-onset diabetes of the young is caused by abnormalities in the HNF1B gene encoding the transcription factor HNF-1β. We aimed to investigate detailed clinical features and the type ...of HNF1B gene anomaly in five pediatric cases with HNF1B-MODY.
Methods: From a cohort of 995 children and adolescents with diabetes, we analyzed the most frequent maturity-onset diabetes of the young genes (GCK, HNF1A, HNF4A) including HNF1B sequencing and deletion analysis by quantitative Multiplex-PCR of Short Fluorescent Fragments (QMPSF) if patients were islet autoantibody-negative and had one parent with diabetes or associated extrapancreatic features or detectable C-peptide outside honeymoon phase. Presence and size of disease-causing chromosomal rearrangements detected by QMPSF were further analyzed by array comparative genomic hybridization.
Results: Overall, five patients had a heterozygous HNF1B deletion, presenting renal disease, elevated liver enzymes, and diabetes. Diabetes was characterized by insulin resistance and adolescent onset of hyperglycemia. Additionally, clinical features in some patients were pancreas dysplasia and exocrine insufficiency (two of five patients), genital defects (three of five), mental retardation (two of five), and eye abnormalities (coloboma, cataract in two of five). One case also had severe growth deficit combined with congenital cholestasis, and another case had common variable immune deficiency. All patients reported here had monoallelic loss of the entire HNF1B gene. Whole genome array comparative genomic hybridization confirmed a precurrent genomic deletion of approximately 1.3–1.7 Mb in size.
Conclusion: The clinical data of our cases enlarge the wide spectrum of patients with HNF1B anomaly. The underlying molecular defect in all cases was a 1.3- to 1.7-Mb deletion, and paired, segmental duplications along with breakpoints were most likely involved in this recurrent chromosomal microdeletion.
HNF1B-Maturity-onset diabetes of youth (MODY) has a broad clinical spectrum and heterozygous contiguous gene deletions, including HNF1B and 18 other known genes.
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