Trisomy 21 Is a Cause of Permanent Neonatal Diabetes That Is Autoimmune but Not HLA Associated.
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SUBMITTER: Johnson MB
PROVIDER: S-EPMC6609990 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:We report 10 heterozygous mutations in the human insulin gene in 16 probands with neonatal diabetes. A combination of linkage and a candidate gene approach in a family with four diabetic members led to the identification of the initial INS gene mutation. The mutations are inherited in an autosomal dominant manner in this and two other small families whereas the mutations in the other 13 patients are de novo. Diabetes presented in probands at a median age of 9 weeks, usually with diabetic ketoacidosis or marked hyperglycemia, was not associated with beta cell autoantibodies, and was treated from diagnosis with insulin. The mutations are in critical regions of the preproinsulin molecule, and we predict that they prevent normal folding and progression of proinsulin in the insulin secretory pathway. The abnormally folded proinsulin molecule may induce the unfolded protein response and undergo degradation in the endoplasmic reticulum, leading to severe endoplasmic reticulum stress and potentially beta cell death by apoptosis. This process has been described in both the Akita and Munich mouse models that have dominant-acting missense mutations in the Ins2 gene, leading to loss of beta cell function and mass. One of the human mutations we report here is identical to that in the Akita mouse. The identification of insulin mutations as a cause of neonatal diabetes will facilitate the diagnosis and possibly, in time, treatment of this disorder.
| S-EPMC1986609 | biostudies-literature
Project description:AimMutations in the ABCC8 gene encoding the SUR1 subunit of the pancreatic ATP-sensitive potassium channel cause permanent neonatal diabetes mellitus (PNDM) and transient neonatal diabetes mellitus (TNDM). We reviewed the existing literature, extended the number of cases and explored genotype-phenotype correlations.MethodsMutations were identified by sequencing in patients diagnosed with diabetes before 6 months without a KCNJ11 mutation.ResultsWe identified ABCC8 mutations in an additional nine probands (including five novel mutations L135P, R306H, R1314H, L438F and M1290V), bringing the total of reported families to 48. Both dominant and recessive mutations were observed with recessive inheritance more common in PNDM than TNDM (9 vs. 1; p < 0.01). The remainder of the PNDM probands (n = 12) had de novo mutations. Seventeen of twenty-five children with TNDM inherited their heterozygous mutation from a parent. Nine of these parents had permanent diabetes (median age at diagnosis: 27.5 years, range: 13-35 years). Recurrent mutations of residues R1183 and R1380 were found only in TNDM probands and dominant mutations causing PNDM clustered within exons 2-5.ConclusionsABCC8 mutations cause PNDM, TNDM or permanent diabetes diagnosed outside the neonatal period. There is some evidence that the location of the mutation is correlated with the clinical phenotype.
| S-EPMC7611803 | biostudies-literature
Project description:ObjectivesTo examine human leukocyte antigen HLA DRB1-DQB1 haplotypes within a multi-ethnic cohort and assess their association with characteristics of diabetes onset.MethodsThe sample included 1662 participants from the SEARCH for Diabetes in Youth Study who tested positive for GADA and/or IA-2A autoantibodies. Blood drawn at the study visit was used to measure fasting C-peptide (FCP) and genotype HLA DRB1 and DQB1 loci. Diabetic ketoacidosis (DKA) at diagnosis was determined from medical records. Multivariable linear and logistic regression models stratified by race/ethnicity were used to assess associations with DRB1-DQB1 haplotypes.ResultsThe frequency of DRB1*03 susceptibility haplotypes ranged 27.5-28.9% in all racial/ethnic groups. The frequency of susceptibility DRB1*04-DQB1*0302 was higher in non-Hispanic White (NHW; 34.1%) and Hispanic (38.9%) compared to non-Hispanic Black (NHB; 20.8%) youth. Neutral and protective haplotypes were low frequency in all groups. DBR1*03 haplotypes were associated with younger age at diagnosis in NHW and positivity for multiple autoantibodies in Hispanics. DRB1*04-DQB1*0302 haplotypes were associated with multiple autoantibody positivity in NHW and Hispanics, and lower FCP and higher odds of DKA in Hispanics only. Although protective DRB1*04-DQB1*0301 haplotypes were associated with older age at diagnosis in NHW, they were also associated with multiple autoantibody positivity in these youth. Protective DRB1*13 haplotypes were associated with decreased odds of multiple autoantibody positivity in NHB youth.ConclusionsThe distribution of DRB1-DQB1 haplotypes and their association with onset-related characteristics of autoimmune diabetes varies across major racial/ethnic groups in the USA. This may contribute to variation in clinical presentation of autoimmune diabetes by race/ethnicity.
| S-EPMC3932799 | biostudies-literature
Project description:Permanent neonatal diabetes mellitus is a rare form of insulin-requiring diabetes presenting within the first few weeks or months of life. Mutations in the insulin gene are the second most common cause of this form of diabetes. These mutations are located in critical regions of preproinsulin and are likely to prevent normal processing or folding of the preproinsulin/proinsulin molecule. To characterize these mutations, we transiently expressed proinsulin-GFP fusion proteins in MIN6 mouse insulinoma cells. Our study revealed three groups of mutant proteins: 1) mutations that result in retention of proinsulin in the endoplasmic reticulum (ER) and attenuation of secretion of cotransfected wild-type insulin: C43G, F48C, and C96Y; 2) mutations with partial ER retention, partial recruitment to granules, and attenuation of secretion of wild-type insulin: G32R, G32S, G47V, G90C, and Y108C; and 3) similar to (2) but with no significant attenuation of wild-type insulin secretion: A24D and R89C. The mutant insulin proteins do not prevent targeting of wild-type insulin to secretory granules, but most appear to lead to decreased secretion of wild-type insulin. Each of the mutants triggers the expression of the proapoptotic gene Chop, indicating the presence of ER stress.
| S-EPMC2838531 | biostudies-literature
Project description:BACKGROUND: Permanent neonatal diabetes mellitus (PNDM) is a rare disease, which is defined as the onset of diabetes before the age of 6 months with persistence through life. Infants with KCNJ11 or ABCC8 genetic mutations may respond to oral sulfonylurea therapy. Currently, there are limited studies about the genetic analysis and long-term follow-up of PNDM. CASE PRESENTATION: We report four cases of PNDM. None of the infants or their parents had INS, KCNJ11, or ABCC8 genetic mutations. One infant underwent continuous subcutaneous insulin infusion (CSII) and the other infants underwent multiple injections of insulin (MII). In these infants, PNDM persisted from 35 months to 60 months of follow-up. Three infants maintained fairly stable blood sugar levels, and one infant had poor sugar control. CONCLUSIONS: We suggest that all of the infants with PNDM should undergo genetic evaluation. For infants without KCNJ11 and ABCC8 genetic mutations, oral sulfonylurea should not be considered as treatment. CSII is a useful method for overcoming the difficulties of diabetes, and it may also improve the quality of life of both infants and their parents.
| S-EPMC4118223 | biostudies-literature
Project description:Transient neonatal diabetes mellitus (TNDM) is diagnosed in the first 6 months of life, with remission in infancy or early childhood. For approximately 50% of patients, their diabetes will relapse in later life. The majority of cases result from anomalies of the imprinted region on chromosome 6q24, and 14 patients with ATP-sensitive K+ channel (K(ATP) channel) gene mutations have been reported. We determined the 6q24 status in 97 patients with TNDM. In patients in whom no abnormality was identified, the KCNJ11 gene and/or ABCC8 gene, which encode the Kir6.2 and SUR1 subunits of the pancreatic beta-cell K(ATP) channel, were sequenced. K(ATP) channel mutations were found in 25 of 97 (26%) TNDM probands (12 KCNJ11 and 13 ABCC8), while 69 of 97 (71%) had chromosome 6q24 abnormalities. The phenotype associated with KCNJ11 and ABCC8 mutations was similar but markedly different from 6q24 patients who had a lower birth weight and who were diagnosed and remitted earlier (all P < 0.001). K(ATP) channel mutations were identified in 26 additional family members, 17 of whom had diabetes. Of 42 diabetic patients, 91% diagnosed before 6 months remitted, but those diagnosed after 6 months had permanent diabetes (P < 0.0001). K(ATP) channel mutations account for 89% of patients with non-6q24 TNDM and result in a discrete clinical subtype that includes biphasic diabetes that can be treated with sulfonylureas. Remitting neonatal diabetes was observed in two of three mutation carriers, and permanent diabetes occurred after 6 months of age in subjects without an initial diagnosis of neonatal diabetes.
| S-EPMC7611811 | biostudies-literature
Project description:ObjectiveNEUROG3 plays a central role in the development of both pancreatic islets and enteroendocrine cells. Homozygous hypomorphic missense mutations in NEUROG3 have been recently associated with a rare form of congenital malabsorptive diarrhea secondary to enteroendocrine cell dysgenesis. Interestingly, the patients did not develop neonatal diabetes but childhood-onset diabetes. We hypothesized that null mutations in NEUROG3 might be responsible for the disease in a patient with permanent neonatal diabetes and severe congenital malabsorptive diarrhea.Research design and methodsThe single coding exon of NEUROG3 was amplified and sequenced from genomic DNA. The mutant protein isoforms were functionally characterized by measuring their ability to bind to an E-box element in the NEUROD1 promoter in vitro and to induce ectopic endocrine cell formation and cell delamination after in ovo chicken endoderm electroporation.ResultsTwo different heterozygous point mutations in NEUROG3 were identified in the proband [c.82G>T (p.E28X) and c.404T>C (p.L135P)], each being inherited from an unaffected parent. Both in vitro and in vivo functional studies indicated that the mutant isoforms are biologically inactive. In keeping with this, no enteroendocrine cells were detected in intestinal biopsy samples from the patient.ConclusionsSevere deficiency of neurogenin 3 causes a rare novel subtype of permanent neonatal diabetes. This finding confirms the essential role of NEUROG3 in islet development and function in humans.
| S-EPMC3064109 | biostudies-literature
Project description:Context and objectiveMutations in EIF2AK3 cause Wolcott-Rallison syndrome (WRS), a rare recessive disorder characterized by early-onset diabetes, skeletal abnormalities, and liver dysfunction. Although early diagnosis is important for clinical management, genetic testing is generally performed after the full clinical picture develops. We aimed to identify patients with WRS before any other abnormalities apart from diabetes are present and study the overall frequency of WRS among patients with permanent neonatal diabetes.Research design and methodsThe coding regions of EIF2AK3 were sequenced in 34 probands with infancy-onset diabetes with a clinical phenotype suggestive of WRS (n = 28) or homozygosity at the WRS locus (n = 6).ResultsTwenty-five probands (73.5%) were homozygous or compound heterozygous for mutations in EIF2AK3. Twenty of the 26 mutations identified were novel. Whereas a diagnosis of WRS was suspected before genetic testing in 22 probands, three patients with apparently isolated diabetes were diagnosed after identifying a large homozygous region encompassing EIF2AK3. In contrast to nonconsanguineous pedigrees, mutations in EIF2AK3 are the most common known genetic cause of diabetes among patients born to consanguineous parents (24 vs. < 2%). Age at diabetes onset and birth weight might be used to prioritize genetic testing in the latter group.ConclusionsWRS is the most common cause of permanent neonatal diabetes mellitus in consanguineous pedigrees. In addition to testing patients with a definite clinical diagnosis, EIF2AK3 should be tested in patients with isolated neonatal diabetes diagnosed after 3 wk of age from known consanguineous families, isolated populations, or countries in which inbreeding is frequent.
| S-EPMC2775655 | biostudies-literature
Project description:BackgroundChildren with neonatal diabetes often present with diabetic ketoacidosis and hence are at risk of cerebral oedema and subsequent long-term neurological deficits. These complications are difficult to identify because neurological features can also occur as a result of the specific genetic aetiology causing neonatal diabetes.Case reportsWe report two cases of neonatal diabetes where ketoacidosis-related cerebral oedema was the major cause of their permanent neurological disability. Case 1 (male, 18 years, compound heterozygous ABCC8 mutation) and case 2 (female, 29 years, heterozygous KCNJ11 mutation) presented with severe diabetic ketoacidosis at 6 and 16 weeks of age. Both had reduced consciousness, seizures and required intensive care for cerebral oedema. They subsequently developed spastic tetraplegia. Neurological examination in adulthood confirmed spastic tetraplegia and severe disability. Case 1 is wheelchair-bound and needs assistance for transfers, washing and dressing, whereas case 2 requires institutional care for all activities of daily living. Both cases have first-degree relatives with the same mutation with diabetes, who did not have ketoacidosis at diagnosis and do not have neurological disability.DiscussionKetoacidosis-related cerebral oedema at diagnosis in neonatal diabetes can cause long-term severe neurological disability. This will give additional neurological features to those directly caused by the genetic aetiology of the neonatal diabetes. Our cases highlight the need for increased awareness of neonatal diabetes and earlier and better initial treatment of the severe hyperglycaemia and ketoacidosis often seen at diagnosis of these children.
| S-EPMC5488205 | biostudies-literature
Project description:IntroductionDelivering unexpected news to families can lead to emotionally charged conversations that cause discomfort and feelings of ineffectiveness in pediatric postgraduate trainees. Although prenatal screening exists, over 80% of trisomy 21 diagnoses continue to be made postnatally to unsuspecting parents who report a desire for better communication from health care professionals when they first receive the news of their child's diagnosis. Recognizing this area for improvement as reported in the literature, as well as the expressed desire from fellows in the University of Ottawa neonatal-perinatal medicine program for additional protected time to preemptively practice such disclosures, this trisomy 21 Scenario-Oriented Learning in Ethics workshop was developed.MethodsDuring the workshop, trainees are introduced to an evidence-based communication framework that provides them with strategies to facilitate clear knowledge translation and promote rapport with families for this specific clinical scenario. Participants are divided into small groups and practice disclosing a trisomy 21 diagnosis to a standardized patient in the role of a new mother. Each small group is supported by two trained facilitators who are experts in delivering life-altering news.ResultsThe pilot workshop was completed by 21 postgraduate trainees from the University of Ottawa. Qualitative evaluations were overwhelmingly positive, with feedback indicating high levels of perceived usefulness for the workshop.DiscussionBy preemptively practicing evidence-based communication, we hope to increase trainee confidence and preparation for trisomy 21 disclosures and improve parents' feelings regarding the quality of communication and support provided while receiving real-life trisomy 21 diagnoses.
| S-EPMC6338174 | biostudies-literature