HNF1A Mutations Research Articles

The Mutation Spectrum of Maturity Onset Diabetes of the Young (MODY)-Associated Genes among Western Siberia Patients.

Maturity onset diabetes of the young (MODY) is a congenital form of diabetes characterized by onset at a young age and a primary defect in pancreatic-β-cell function. Currently, 14 subtypes of MODY are known, and each is associated with mutations in a specific gene: HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, KCNJ11, ABCC8, and APPL1. The most common subtypes of MODY are associated with mutations in the genes GCK, HNF1A, HNF4A, and HNF1B. Among them, up to 70% of cases are caused by mutations in GCK and HNF1A. Here, an analysis of 14 MODY genes was performed in 178 patients with a MODY phenotype in Western Siberia. Multiplex ligation-dependent probe amplification analysis of DNA samples from 50 randomly selected patients without detectable mutations did not reveal large rearrangements in the MODY genes. In 38 patients (37% males) among the 178 subjects, mutations were identified in HNF4A, GCK, HNF1A, and ABCC8. We identified novel potentially causative mutations p.Lys142*, Leu146Val, Ala173Glnfs*30, Val181Asp, Gly261Ala, IVS7 c.864 −1G>T, Cys371*, and Glu443Lys in GCK and Ser6Arg, IVS 2 c.526 +1 G>T, IVS3 c.713 +2 T>A, and Arg238Lys in HNF1A.

Prenatal diagnosis of HNF1b mutation allows recognition of neonatal dysglycemia

Maturity onset diabetes of the young (MODY) is the most common form of monogenic diabetes in Europe, affecting between 1 and 6% of diabetic patients. It comprises a group of heterogeneous genetic disorders characterized by early onset of diabetes (commonly before age 25), absence of autoimmunity, and beta-cell dysfunction. So far, mutations in 14 different genes involved in glucose homeostasis and pancreatic development [1] have been associated with this disease. Although it is an autosomal dominant disorder, de novo mutations should be taken into consideration in patients without a family history of diabetes. Most cases of MODY are due to mutations in GCK, HNF1a, HNF4a and HNF1b, previously known as MODY2, MODY3, MODY1, and MODY5, respectively. Among these, HNF1b is an active transcription factor that forms homodimers or heterodimers with HNF1a and plays a fundamental role in kidney development, nephron differentiation, and pancreatic growth and differentiation. Mutations in this gene lead to congenital anomalies of the kidney and urinary tract, genital malformations, pancreatic atrophy with endocrine and exocrine deficiency [2]. Diabetes usually onsets in early adulthood and frequently requires insulin treatment. We present an unusual case of a prenatal diagnosis that revealed a mutation in the HNF1b gene responsible for neonatal hyperglycemia in a pregnant woman affected by X-linked ectodermal dysplasia.

Identification of the First PAX4-MODY Family Reported in Brazil.

PurposeThe aim of this study was to sequence the coding region of the PAX4 gene in a Brazilian cohort with clinical manifestations of monogenic diabetes.Patients and MethodsThis study included 31 patients with autosomal dominant history of diabetes, age at diagnosis ≤40 years, BMI <30 kg/m2, and no mutations in GCK or HNF1A, HNF4A, and HNF1B. Screening of the PAX4 coding region was performed by Sanger sequencing. In silico algorithms were used to assess the potential impact of amino acid substitutions on protein structure and function. Additionally, PAX4-MODY family members and 158 control subjects without diabetes were analyzed for the identified mutation.ResultsThe molecular analysis of PAX4 has detected one missense mutation, p.Arg164Gln (c.491G>A), segregating with diabetes in a large Brazilian family. The mutation was absent among the control group. The index case is a woman diagnosed at 32 years of age with polyneuropathy and treated with insulin. She did not present diabetic renal disease or retinopathy. Family members with the PAX4 p.Arg164Gln mutation have a heterogeneous clinical manifestation and treatment response, with age at diagnosis ranging from 24 years to 50 years.ConclusionTo the best of our knowledge, this is the first study to report a PAX4-MODY family in Brazil. The age of PAX4-MODY diagnosis in the Brazilian family seems to be higher than the classical criteria for MODY. Our results reinforce the importance of screening large monogenic diabetes families for the understanding of the clinical manifestations of rare forms of diabetes for the specific and personalized treatment.

A Novel HNF4A Mutation Causing Three Phenotypic Forms of Glucose Dysregulation in a Family

Maturity-onset diabetes of the young (MODY) classically describes dominantly inherited forms of monogenic diabetes diagnosed before 25 years of age due to pancreatic β-cell dysfunction. In contrast, mutations in certain MODY genes can also present with transient or persistent hyperinsulinemic hypoglycemia in newborn infants, reflecting instead β-cell dysregulation. Of the MODY genes described to date, only hepatocyte nuclear factor-4-alpha (HNF4A; MODY1) and hepatocyte nuclear factor-1-alpha (HNF1A; MODY3) mutations may result in a biphasic phenotype of hypoglycemia in early life and hyperglycemia in later life. We report a family with a novel HNF4A mutation with diverse phenotypic presentations of glucose dysregulation. The proband was a term, appropriate-for-gestational age male infant with symptomatic hypoglycemia on day 3 of life needing high glucose infusion rate to maintain normoglycemia. He was born to a non-obese and non-diabetic mother. Glucose regulation was optimized using diazoxide upon confirmation of hyperinsulinism. Cascade genetic screening identified the same mutation in his father and elder sister, but mother was negative. Father was diagnosed with Type 1 diabetes at 15 years of age that required insulin therapy. Proband's elder sister, born at term appropriate for gestational age, presented with transient neonatal hypoglycemia needing parenteral glucose infusion for a week followed by spontaneous resolution. The paternal grandparents were negative for this mutation, confirming a paternal de novo mutation and autosomal dominant inheritance in this family. This pedigree suggests that the presence of early-onset paternal diabetes should prompt molecular testing in infants presenting in the newborn period with diazoxide-responsive hyperinsulinemic hypoglycemia, even in the absence of maternal diabetes and macrosomia.

GIP and GLP-1 Potentiate Sulfonylurea-Induced Insulin Secretion in Hepatocyte Nuclear Factor 1α Mutation Carriers.

Sulfonylureas (SUs) provide an efficacious first-line treatment in patients with hepatocyte nuclear factor 1α (HNF1A) diabetes, but SUs have limitations due to risk of hypoglycemia. Treatment based on the incretin hormones glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1) is characterized by their glucose-dependent insulinotropic actions without risk of hypoglycemia. The effect of SUs together with GIP or GLP-1, respectively, on insulin and glucagon secretion in patients with HNF1A diabetes is currently unknown. To investigate this, 10 HNF1A mutation carriers and 10 control subjects without diabetes were recruited for a double-blinded, placebo-controlled, crossover study including 6 experimental days in a randomized order involving 2-h euglycemic-hyperglycemic clamps with coadministration of: 1) SU (glimepiride 1 mg) or placebo, combined with 2) infusions of GIP (1.5 pmol/kg/min), GLP-1 (0.5 pmol/kg/min), or saline (NaCl). In HNF1A mutation carriers, we observed: 1) hypoinsulinemia, 2) insulinotropic effects of both GIP and GLP-1, 3) additive to supra-additive effects on insulin secretion when combining SU+GIP and SU+GLP-1, respectively, and 4) increased fasting and arginine-induced glucagon levels compared with control subjects without diabetes. Our study suggests that a combination of SU and incretin-based treatment may be efficacious in patients with HNF1A diabetes via potentiation of glucose-stimulated insulin secretion.

1900-P: HNF1A Deficiency Leads to Perturbed Glucagon Secretion in Humans

Mutations in HNF1A cause Maturity Onset Diabetes of the Young (HNF1A-MODY). Carriers are normoglycemic in childhood, but with age, they develop hyperglycemia associated with insulin secretory defects and beta cell dysfunction. Although endogenous glucose production has been reported, glucagon in HNF1A-MODY has been less explored. Patients respond well to low dose sulfonylureas such as gliclazide, which increases insulin secretion independent of glucose but may predispose to hypoglycemia. We aimed to investigate whether low dose gliclazide had an effect on glucagon secretion in HNF1A-MODY. Additionally, we explored the potential of GLP-1 to normalize hormone secretion using in vivo and in vitro models of HNF1A deficiency. A 75g oral glucose tolerance test was performed in 7 MODY patients before and 72h after stopping gliclazide. Glucose rise was greater off gliclazide (p=0.003), while c-peptide and glucagon levels were similar between the groups. When adjusting for glucose levels during the OGTT, the change from baseline glucagon levels (Δ glucagon/glucose ratio) showed a significant decrease in those taking gliclazide (p=0.048), while there was no difference in Δ c-peptide/glucose ratio. Hnf1a-/- mice compared to WT mice are hyperglycemic, have decreased plasma insulin levels and hyperglucagonemia that was not suppressed after a glucose challenge (p=0.008). Furthermore, induction of the HNF1A variant Pro291fsInsC in rat INS1 cells reduced insulin and increased glucagon secretion, both of which were improved by GLP-1 treatment. Using the TIGER database we found HNF1A to be heterogeneously expressed in human islets, and siHNF1A reduced insulin secretion at high glucose. Collectively, these findings indicate that HNF1A is also essential for the regulation of glucagon secretion and glucose homeostasis. The mechanism by which GLP-1 normalizes insulin and glucagon secretion needs further investigation but could contribute to a better understanding of treatment response in HNF1A-MODY. Disclosure C. Saponaro: None. A. Acosta-Montalvo: None. L. Anguelova: None. J. Thevenet: None. M. Chiral: None. G. Pasquetti: None. A. Piron: None. M. Cnop: None. V. Gmyr: None. J. Prehn: None. J.A. Kerr-Conte: None. F. Pattou: None. M. Pontoglio: None. K.R. Owen: None. I. Spiliotis: None. C. Bonner: None. Funding European Foundation for the Study of Diabetes/Lilly European Diabetes Research Programme; Oxford Health Sciences Research Committee (1233)

2050-P: A Multiomics Investigation of a Patient-Derived HNF-1A MODY IPSC Disease Model Reveals Insights into Its Role in Pancreatic Islet Development and Function

Heterozygous loss of function mutations in HNF1A, encoding the transcription factor hepatocyte nuclear factor 1 alpha (HNF-1A) are the most common cause of monogenic diabetes. HNF-1A is involved in both beta cell development and mature cell function. However, model organisms have often failed to faithfully recapitulate the human phenotypes. As such, we used a patient-derived HNF1A Pro291fsinsC iPSC model and CRISPR-Cas9 genome editing to correct the mutation and generate an isogenic control. iPSC clones (n=6) were differentiated towards the endocrine lineage in triplicate, with RNA-seq (bulk and single-cell) and ATAC-seq performed at definitive endoderm (DE), pancreatic endoderm (PE) and beta-like cells (BLC) stages. RNA-seq data confirmed HNF1A haploinsuffiency in the patient cell lines, with corrected cell lines demonstrating restored HNF1A expression at both transcript and protein level. At the BLC stage, there was a significant overlap in differentially expressed genes and HNF1A targets identified in an independent HNF1A knock-down experiment in the EndoC-βh1 cell line (p=4.4e-132). Corrected clones demonstrated a higher expression of INS (p=7.2e-03), insulin secretion genes and effects on pancreas progenitor cell genes indicating that HNF1A may mediate the cellular composition of the pancreatic islet. Bulk RNA-seq data were also supported in the preliminary analysis of the single-cell RNA-seq data. Open chromatin, assessed by ATAC-seq was significantly different between patient and corrected lines, with &amp;gt;90% of the sites being more accessible at both PE and BLC stages in the corrected clones. These sites were enriched for HNF1A binding motifs, implicating HNF1A in the establishment of open chromatin. In conclusion, our patient-derived HNF1A-MODY iPSC model recapitulates a number of features of HNF1A-MODY, as well as providing insights into the cellular and molecular phenotypes caused by HNF-1A deficiency. Disclosure C. Duff: Research Support; Self; Novo Nordisk A/S. R. Jensen: None. M. Perez-Alcantara: None. M. Rasmussen: None. A. Grotz: None. M. Jansen: None. B. Holst: None. C. Clausen: None. N.A.J. Krentz: None. M. Hansson: Employee; Self; Novo Nordisk A/S. M.I. McCarthy: Advisory Panel; Self; Illumina. Consultant; Self; Eli Lilly and Company, Novo Nordisk Inc., Zoe Global Ltd. Employee; Self; Genentech, Inc. Research Support; Self; AbbVie Inc., Merck &amp; Co., Inc., Sanofi-Aventis, Servier, Takeda UK. A.L. Gloyn: Consultant; Self; Merck Sharp &amp; Dohme Corp. Employee; Spouse/Partner; Genentech, Inc. Research Support; Self; Novo Nordisk A/S. A. Wesolowska-Andersen: None. C. Honore: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. Funding Innovative Medicines Initiative (115439)

1312-P: Pancreas Volume in Individuals with MODY 1, 2, 3, and 5

Individuals with new-onset type 1 diabetes (T1D) have a smaller pancreas volume, which declines further during the first years after diagnosis. Whether this reflects the insulin deficiency associated with T1D or the underlying process leading to T1D is not clear. Mutations in several genes that are active in the pancreas and/or pancreatic islet cells cause varying degrees of insulin deficiency, resulting in Maturity Onset Diabetes of Youth (MODY). To determine whether decreased pancreas volume is associated with these other forms of diabetes, we used a standardized MRI protocol that has been validated in over 500 scans to measure pancreas volume normalized to body weight (pancreas volume index, PVI). Individuals with mutations in HNF4A (MODY 1, ages 19-71, PVI 0.79 ± 0.07 mL/kg, N=4), GCK (MODY 2, ages 9-55, PVI 0.97 ± 0.10 mL/kg, N=5), or HNF1A (MODY 3, ages 16-60, PVI 0.80 ± 0.09 mL/kg, N=7) had pancreas volume similar to controls (ages 8-65, 0.96 ± 0.03 mL/kg, N=78, p&amp;gt;0.59). Pancreas volume was not different in individuals with MODY 1, 2, or 3 who required insulin replacement therapy compared with those not on insulin (PVI 0.82 ± 0.08 vs. 0.89 ± 0.09 mL/kg, N=9 and 7, p=0.56). Individuals with a mutation in HNF1B (MODY 5), a less common mutation that can be associated with pancreatic hypoplasia, had widely variable pancreas volume (PVI 0.90 ± 0.36 mL/kg, N=3). Further studies to assess pancreas size in other forms of MODY are needed and may provide insight into why the pancreas volume is reduced in T1D. Disclosure J.J. Wright: None. J.M. Williams: None. J. Virostko: None. M.A. Hilmes: None. L. Du: None. H. Kang: None. S.W. Greeley: None. W.E. Russell: None. D.J. Moore: None. A.C. Powers: None. Funding JDRF (3-SRA-2019-759-M-B, 3-SRA-2015-102-M-B)

127-LB: Characteristics of INS-MODY Participants in a National Diabetes Registry

Introduction: Maturity onset diabetes of the young (MODY) may represent 2-5% of diabetes under 30-35 years. Rarely MODY may be due to mutation in the INS gene. HNF1A mutations are well described causes of MODY and may be treated with low dose sulfonylurea. Our aim was to compare clinical features and treatment of INS-MODY with HNF1A-MODY cohort population. Methods: Participants enrolled through the U.S. Monogenic Diabetes Registry, with Sanger or next-generation sequencing completed with causal mutations found in INS or HNF1A, diagnosed after 13 months of age. Those with neonatal diabetes due to INS were excluded. Results: Each group shared similar demographics (Table 1). Common presenting symptoms in each group included polyuria, polydipsia, weight loss, fatigue (Table 1). In the INS cohort, all showed residual c-peptide. None reported DKA. The majority had used insulin, though there were a variety of treatment modalities, even among those with the same mutation (Figure 1). For HNF1A cohort, over 60% had been on insulin or sulfonylurea, with 40% having discontinued insulin. Conclusion: Review of treatments in INS cohort consist of multiple agents with majority using insulin at some point. If clinical suspicion of MODY, genetic testing may help inform treatment. It appears that some variants of INS-MODY lead to a progressive disease eventually requiring insulin therapy and early insulin may improve outcomes. Disclosure M. McCauley: None. S. Korkmaz: None. L.R. Letourneau-Freiberg: None. R.N. Naylor: None. S.W. Greeley: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK104942, P30DK0205950); National Center for Advancing Translational Sciences (UL1TR002389)

MON-646 Novel Use of GLP-1 Receptor Agonist Therapy in MODY-1 (HNF4A Mutation)

Monogenic Diabetes (MODY) results from mutations or changes in a single gene, and currently account for about 1 to 4% of all cases of diabetes (1). Our group has previously published on the successful use of glucagon-like peptide-1 receptor agonist (GLP-1 RA) therapy in three consecutive generations of a family with an HNF1A mutation (MODY-3) (2). Although GLP-1 RA therapy has been studied in patients with HNF1A mutations (MODY-3) (3), it has not been studied in patients with HNF4A mutations (MODY-1). In this father-son cohort, we demonstrate successful use of GLP-1 RA therapy in two patients with c.790:1 bp deletion of G; codon:264 mutations of HNF4A. The son first presented with neonatal hypoglycemia, then later developed diabetes and presented to our clinic at age 20, when genetic testing was performed and confirmatory for an HNF4A mutation. He was prescribed glimepiride and titrated to 4 mg twice daily, and two years later, his hemoglobin A1c (HbA1c) rose to 8.7%. He was switched to semaglutide 0.25 mg once weekly and was titrated to a maximum dose of 1 mg weekly over 8 weeks. The patient reports improvement in his post-prandial blood glucose values at this time, but HbA1c has not yet been repeated. The father had been diagnosed with monogenic diabetes in his early 20s and had been on sulfonylurea therapy until age 40, at which time he was transitioned to a regimen of long- and short-acting insulin therapy. Thereafter, he presented to our clinic in July, 2018 with a HbA1c of 9.6% and was transitioned to long-acting insulin once daily and liraglutide 0.6 mg once daily which was subsequently titrated to 1.8 mg once daily over 3 weeks. The patient tolerated this well and has been off short acting insulin since December 2018, with notable improvement in his HbA1c to 5.9% and marked improvement in his post-prandial glycemic control. To our knowledge this is the first report demonstrating the benefits of GLP-1 RA therapy in patients with the HNF4A mutations (MODY-1). Based on this report, it appears that GLP-1 RA therapy could be an effective therapy in patients with MODY-1.1). Pihoker C, Gilliam LK, Ellard S, et al. Prevalence, characteristics and clinical diagnosis of maturity onset diabetes of the young due to mutations in HNF1A, HNF4A, and glucokinase: results from the SEARCH for Diabetes in Youth. The Journal of Clinical Endocrinology and Metabolism. 2013;98(10):4055–4062.2). Maricor Docena, Charles Faiman, Christine Stanley, and Kevin Pantalone (2014) Mody-3: Novel HNF1A Mutation and the Utility of Glucagon-Like Peptide (GLP)-1 Receptor Agonist Therapy. Endocrine Practice: February 2014, Vol. 20, No. 2, pp. 107–111.3). Ostoft SH, Bagger JI, Hansen T, et al. Glucose-lowering effects and low risk of hypoglycemia in patients with maturity-onset diabetes of the young when treated with a GLP-1 receptor agonist: a double-blind, randomized, crossover trial. Diabetes Care. 2014;37(7):1797–17805.

SUN-690 HNF4A Mutation in Siblings with Diazoxide Responsive Congenital Hyperinsulinism

Background: Congenital hyperinsulinism (HI) is the leading cause of severe, persistent hypoglycemia in infants. Transient HI seen at risk neonates due to prenatal stress and some of the congenital HI cases due to mutations in K-ATPase channel are responsive to diazoxide. It is not a common practice to obtain genetic evaluation for diazoxide responsive HI. However, children with dominant inactivating variants in HNF4A gene may present with diazoxide-responsive HI and mimic transient HI in infancy. Objective: To describe two siblings with diazoxide responsive HI with HNF4A mutation associated with maturity onset diabetes of youth type 1 (MODY1). Clinical Case: Case 1, term female with macrosomia and Case 2, preterm male appropriate for gestational age were born to same mother without gestational diabetes and with no perinatal stress. Siblings were non-dysmorphic and both presented with hypoglycemia during first week of life. Diagnosis of HI is confirmed based on inappropriately suppressed β-hydroxybutyrate at the time of hypoglycemia and inappropriate glycemic response to glucagon consistent with increased insulin action. Both siblings responded to diazoxide therapy. Family history was significant for late-onset diabetes in paternal extended family. Case 1 required very low dose diazoxide (2 mg/kg/day) during first year of life to sustain normoglycemia. She came off of diazoxide at 19 months of age. Case 2 is normoglycemic on 5mg/kg/day diazoxide at 4 months of age. Genetic evaluation through whole exome sequencing pursued upon diagnosis of Case 2 revealed paternally inherited heterozygous pathogenic start loss variant in HNF4A gene (c.3G>T) in both siblings. Father was completely asymptomatic without any history of hypo- or hyperglycemia. Conclusion: HNF4A gene encodes hepatocyte nuclear factor-4-alpha that regulates hepatic gluconeogenesis and lipid metabolism. Dominant inactivating variants in HNF4A gene associated with familial HI, are typically associated with increased size for gestational age, mild diazoxide-responsive hypoglycemia (which may be transient) and monogenic diabetes during adolescence. HNF4A mutations were described as one of the most common genetic cause of diazoxide-responsive congenital hyperinsulinism and are associated with MODY1. It is important to consider genetic evaluation in diazoxide responsive HI cases. Identifying children with HNF4A variant early on will impact their long-term follow-up leading to earlier diagnosis and treatment of MODY-1 and potentially improve long-term outcomes.

MON-LB120 MODY3 With Insulin Coding Gene Mutation and Craniofacial Microsomia: A Case Report

Background: Maturity onset diabetes in young 3 (MODY 3) is caused by mutation of the hepatic nuclear factor 1 alpha (HNF-1A) gene. Craniofacial macrosomia (CFM) is associated with an abnormal development of craniofacial structures during the embryonic period. Maternal diabetes and genetic predisposition have been associated with CFM1. There are rare reports about an association of MODY 3 and CFM. Clinical case: An 11-year-old male patient presented with right side CFM (mild mandibular hypoplasia, internal auditory canal absence, severe pinna hypoplasia, abnormal orbital size and location, O3.M0.E3.N0.S02) noted at 8 months of age. Preoperative examination revealed A1c at 10.9%. After short term intensive insulin therapy, he had standard bread meal test: fasting glucose 8.11 mmol/L, insulin 13.9 mIU/L (3-25), C-peptide 1.25 ng/ml (0.81-3.85); 1 hour glucose 10.05 mmol/L, insulin 27 mIU/L, C-peptide 2.42 ng/ml; 2 hour glucose 8.17 mmol/L, insulin 16.09 mIU/L, C-peptide 2.11 ng/ml. GADA, IAA and ICA were negative. The mother was diagnosed diabetes at age 27years, when the patient was 8-month-old, and received insulin therapy. The mother was blind by age 35years due to diabetic retinopathy and died of DKA at 38-years-old. The patient’s 16-year-old brother had left side CFM (O2.M1.E2.N0.S0) and his OGTT was normal. The father was diagnosed with impaired glucose tolerance. The family had whole genome sequencing by Sanger technique, and resequenced the mutation with side primers. The CGA to CAA mutation was present at the 686 loci of exon 3 of HNF1A gene in the patient and mother. The HNF1A exon 3 mutation of CGA to CAA resulted in the change of arginine to glutamine which by the HGMA database is recognized as a reported MODY3 gene mutation. There was a mutation of G to A in the 4 loci of exon 1 of the insulin coding region in chromosome 11 in both the patient and elder brother. Neither elder brother nor father had the CGA mutation of HNF1A. Conclusion: There has not been a previous report of a relationship between HNF1A and CFM. In this case, the elder brother had CFM without a HNF1A mutation which does not support a connection between CFM and HNF1A. The two brothers both had CFM and insulin coding gene mutations which would represent a new association not previously described. Further testing is needed to confirm a relationship between the two. Reference: 1. Chen Q, Zhao Y, Shen G, Dai J. Etiology and Pathogenesis of Hemifacial Microsomia. J Dent Res 2018; 97(12): 1297-305. 2. Gougoutas AJ, Singh DJ, Low DW, Bartlett SP. Hemifacial microsomia: clinical features and pictographic representations of the OMENS classification system. Plast Reconstr Surg 2007; 120(7): 112e-20e.

The effect of linagliptin treatment on gut microbiota in patients with HNF1A-MODY or type 2 diabetes — a preliminary cohort study

Introduction. Many studies have evaluated the relationship between diabetes and microbiota. In animal models, the dipeptidyl peptidase-4 inhibitors altered the gut microbiota. We investigated whether linagliptin alters the gastrointestinal flora in humans. Materials and methods. This prospective cohort study enrolled 24 patients: 5 patients with maturity onset diabetes of the young associated with HNF1A mutation and 19 patients with type 2 diabetes mellitus. Stool samples were collected at baseline and 4 weeks after treatment intensification with either linagliptin or a sulphonylurea alongside current treatment. Faecal 16S rRNA was analysed by next-generation sequencing. Results. Nine patients initiated linagliptin whereas 15 patients initiated or increased the dose of a sulphonylurea. After linagliptin treatment, we did not observe changes in taxa in L2–L7 based on analysis of composition of microbiomes (ANCOM). The same held true for pairwise alpha diversity (Shannon diversity, p = 0.59; Pielou’s measure of evenness, p = 0.68; and observed operational taxonomic units [OTUs], p = 0.77) and beta diversity distances (unweighted UniFrac, p = 0.99; weighted UniFrac, p = 0.93; Bray-Curtis, p = 0.98; and Jaccard, p = 0.99). Similarly, after sulphonylurea intensification, we did not observe changes in taxa in L2–L7 in ANCOM, nor were there changes in alpha diversity (Shannon diversity, p = 0.19; Pielou’s measure of evenness, p = 0.21; and observed OTUs, p = 0.42) or beta diversity distances (unweighted UniFrac, p = 0.99; weighted UniFrac, p = 0.99; Bray-Curtis, p = 1; and Jaccard, p = 0.99). Conclusion. We did not observe changes in colonic microbiota 4 weeks after addition of linagliptin to current diabetes treatment. Further studies are required to determine whether linagliptin influences the colonic microbiota in humans.

Comprehensive analysis in mucin-producing urothelial-type adenocarcinoma of the prostate: case study with literature review.

It is critical to distinguish the rare neoplasm of mucin-producing urothelial-type adenocarcinoma of the prostate (MPUAP) from either prostate origin or metastatic adenocarcinoma. This is mainly because they have different tumor staging, clinical behavior and treatment plans. In the current study, we try to fulfill the lack of knowledge in this field. There were totally 24 MPUAP cases including previous reported 23 cases and adding one new MPUAP case in the current study. We performed IHC and 78 genes panel analysis in two cases of ours. Most of the cases had urinary obstruction symptoms and normal PSA level. Pathological features showed dissection of the stroma by mucin pools and glands lined by pseudostratified columnar mucinous epithelium with varying degrees of cytological atypia. The IHC results showed positive for CK20, CEA, CDX-2, β-catenin, p53, MUC2 and MUC5AC, negative for PSA, AMACR, GATA3, MUC6, AR and NKX3.1 and variable expression for HMWCK and CK7. Genetic analysis revealed concurrent mutations of FAT1 (c.10001 T>C) and HNF1A in both cases. The similar morphology features of MPUAP and colorectal adenocarcinoma were seen. Membranous staining pattern of β-catenin and genetic mutation of FAT1 and HNF1A are two distinct features in MPUAP.

Primary hepatocellular adenoma due to biallelic HNF1A mutations and its co-occurrence with MODY 3: case-report and review of the literature

PurposeMaturity-onset diabetes of the young type 3 (MODY 3) is a consequence of heterozygous germline mutations in HNF1A, and a subtype of hepatocellular adenoma (HCA) is caused by biallelic somatic HNF1A mutations; rare HCA may be related to MODY 3. This study aimed to investigate the cosegregation of HNF1A mutations with diabetes and HCA in two families.MethodsTwo patients suffering from HCA and diabetes were screened for HNF1A germline and somatic mutations using direct sequence analysis and methylation-specific multiplex-ligation-dependent probe amplification (MS-MLPA) assay. Further, we screened eight relatives in the two independent families for diabetes, HCA and HNF1A variants. Additionally, we reviewed the literature concerning the phenotypes of MODY 3 and HCA at the background of HNF1A mutations.ResultsHere we reported two families (a total of six relatives) with two missense germline mutations of HNF1A identified initially using direct sequence analysis (c.686G>A in family A and c.526 + 1G>A in family B). Somatic deletion of the second allele of HNF1A was found in liver tumor tissues in both probands who were diagnosed with HCA. There are a total of ten cases of both MODY 3 and HCA phenotypes reported in the literature to date; incomplete penetrance for HCA was observed, and all the patients with HCA developed diabetes. The onset of diabetes and HCA was highly variable, the treatment of diabetes varied from diet to insulin, and the clinical expression of HCA ranged from silent to hemorrhage. Further, the severity of diabetes mellitus was not related to the occurrence of HCA.ConclusionsThis study describes the association of HCA and MODY 3 at the background of HNF1A mutations and highlights the importance of screening for HCA in MODY 3 families to avoid the possibility of severe complications. Further, the current study indicated that there may be a special mutational spectrum of HNF1A correlated with HCA in MODY 3 families.

Human iPSCs-Derived Endothelial Cells with Mutation in HNF1A as a Model of Maturity-Onset Diabetes of the Young

Patients with HNF1A-maturity-onset diabetes of the young (MODY) often develop endothelial dysfunction and related microvascular complications, like retinopathy. As the clinical phenotype of HNF1A-MODY diabetes varies considerably, we used human induced pluripotent stem cells (hiPSCs) from two healthy individuals (control) to generate isogenic lines with mutation in HNF1A gene. Subsequently, control hiPSCs and their respective HNF1A clones were differentiated toward endothelial cells (hiPSC-ECs) and different markers/functions were compared. Human iPSC-ECs from all cell lines showed similar expression of CD31 and Tie-2. VE-cadherin expression was lower in HNF1A-mutated isogenic lines, but only in clones derived from one control hiPSCs. In the other isogenic set and cells derived from HNF1A-MODY patients, no difference in VE-cadherin expression was observed, suggesting the impact of the genetic background on this endothelial marker. All tested hiPSC-ECs showed an expected angiogenic response regardless of the mutation introduced. Isogenic hiPSC-ECs responded similarly to stimulation with pro-inflammatory cytokine TNF-α with the increase in ICAM-1 and permeability, however, HNF1A mutated hiPSC-ECs showed higher permeability in comparison to the control cells. Summarizing, both mono- and biallelic mutations of HNF1A in hiPSC-ECs lead to increased permeability in response to TNF-α in normal glycemic conditions, which may have relevance to HNF1A-MODY microvascular complications.

MODY probability calculator for GCK and HNF1A screening in a multiethnic background population.

Objective We aimed to identify the frequency of monogenic diabetes, which is poorly studied in multiethnic populations, due to GCK or HNF1A mutations in patients with suggestive clinical characteristics from the Brazilian population, as well as investigate if the MODY probability calculator (MPC) could help patients with their selection. Subjects and methods Inclusion criteria were patients with DM diagnosed before 35 years; body mass index < 30 kg/m2; negative autoantibodies; and family history of DM in two or more generations. We sequenced HNF1A in 27 patients and GCK in seven subjects with asymptomatic mild fasting hyperglycemia. In addition, we calculated MODY probability with MPC. Results We identified 11 mutations in 34 patients (32.3%). We found three novel mutations. In the GCK group, six cases had mutations (85.7%), and their MODY probability on MPC was higher than 50%. In the HNF1A group, five of 27 individuals had mutations (18.5%). The MPC was higher than 75% in 11 subjects (including all five cases with HNF1A mutations). Conclusion Approximately one third of the studied patients have GCK or HNF1A mutations. Inclusion criteria included efficiency in detecting patients with GCK mutations but not for HNF1A mutations (< 20%). MPC was helpful in narrowing the number of candidates for HNF1A screening.

Mutations in transcription factor as rare causes of diabetes in pregnancy

MODY1 and MODY3 represent rare causes of diabetes in pregnancy. Establishing a molecular diagnosis of MODY1 or MODY3 during pregnancy may be important for minimizing risk of perinatal complications and for improving glycemic control after pregnancy. The objective of the study was to evaluate the contribution of mutations in HNF4A and HNF1A genes in development of diabetes in pregnancy and to describe clinical characteristics of diabetes in pregnancy associated with these mutations. 230 pregnant women (20-43 years) with different type of glucose intolerance complicated during their current pregnancy were included in the study. A custom NGS panel targeting 28 diabetes causative genes was used for sequencing. Heterozygous mutations in HNF4A and HNF1A genes were detected in 3% of cases. Mutations p.I271T in HNF4A gene and p.L148F, p.Y265C, p.G288W in HNF1A gene were novel. This study includes a description of patients with pregnancy diabetes due to mutations in hepatocyte nuclear factors.

Natural history of liver adenomatosis: A long-term observational study

Liver adenomatosis (LA) is characterized by the presence of at least 10 hepatocellular adenomas (HCAs), but the natural history of this rare liver disorder remains unclear. Thus, we aimed to reappraise the natural history and the risk of complications in a cohort of patients with at least 10 HCAs. We analyzed the natural history of 40 patients with LA, excluding glycogen storage disorders, in a monocentric cohort. Pathological examination was performed, with immunostaining and molecular biology carried out on surgical specimens or liver biopsies. Forty patients (36 female) were included with a median follow-up of 10.6 (1.9-26.1) years. Six (15%) patients had familial LA, all with germline HNF1A mutations. Median age at diagnosis was 39 (9-55) years. Thirty-three (94%) women had a history of oral contraception, and 29 (81%) women had a pregnancy before LA diagnosis. Overall, thirty-seven (93%) patients underwent surgery at diagnosis. Classification of HCAs showed 46% of patients with HNF1A-mutated HCA, 31% with inflammatory HCA, 3% with sonic hedgehog HCA, 8% with unclassified HCA. Only 15% of the patients demonstrated a "mixed LA" with different HCA subtypes. Hepatic complications were identified in 7 patients: 1 patient (3%) died from recurrent hepatocellular carcinoma after liver transplantation; 6 (15%) had hemorrhages, of which 5 occurred at diagnosis, with 1 fatal case during pregnancy, and 2 occurred in male patients with familial LA. Four patients (10%) had repeated liver resections. Finally, 4 (10%) patients developed extrahepatic malignancies during follow-up. The diversity in HCA subtypes, as well as the occurrence of bleeding and malignant transformation during long-term follow-up, underline the heterogeneous nature of LA, justifying close and specific management. In patients with germline HNF1A mutation, familial LA occurred equally frequently in males and females, with a higher rate of bleeding in male patients. Liver adenomatosis is a rare disease characterized by the presence of 10 or more hepatocellular adenomas that may rarely be of genetic origin. Patients with liver adenomatosis have multiple adenomas of different subtypes, with a risk of bleeding and malignant transformation that justify a specific management and follow-up.

Modeling Monogenic Diabetes using Human ESCs Reveals Developmental and Metabolic Deficiencies Caused by Mutations in HNF1A.

Human monogenic diabetes, caused by mutations in genes involved in beta cell development and function, has been a challenge to study because multiple mouse models have not fully recapitulated the human disease. Here, we use genome edited human embryonic stem cells to understand the most common formof monogenic diabetes, MODY3, caused by mutations in the transcription factor HNF1A. We found that HNF1A is necessary to repress an alpha cell gene expression signature, maintain endocrine cell function, and regulate cellular metabolism. In addition, we identified the human-specific long non-coding RNA, LINKA, as an HNF1A target necessary for normal mitochondrial respiration. These findings provide a possible explanation for the species difference in disease phenotypes observed with HNF1A mutations and offer mechanistic insights into how the HNF1A gene may also influence type 2diabetes.