Prolonged episodes of hypoglycaemia in HNF4A-MODY mutation carriers with IGT. Evidence of persistent hyperinsulinism into early adulthood

Management of pregnancy in women with monogenic diabetes due to mutations in GCK, HNF1A and HNF4A genes

Women with maturity-onset diabetes of the young (MODY) need tailored antenatal care and monitoring of their offspring. Each MODY subtype has different implications for glycaemic targets, treatment choices and neonatal management. Hyperglycaemia of MODY is often first diagnosed in adolescence or early adulthood and therefore is clinically relevant to pregnant women. MODY remains an under-recognised and undiagnosed condition. Pregnancy represents an opportune time to make a genetic diagnosis of MODY and provide precision treatment. This review describes the nuance of antenatal care in women with MODY and the implications for pregnancies affected by a positive paternal genotype. Mutations in hepatic nuclear factor 1-alpha (HNF1A) and 4-alpha (HNF4A) genes are associated with progressive β-cell dysfunction resulting in early onset diabetes. Patients are largely managed with sulphonylureas outside of pregnancy. Macrosomia and persistent neonatal hypoglycaemia are reported in 54% and 15% of HNF4A genotype positive offspring respectively with a median increase in birthweight of 790 g. Close observation of foetal growth in utero allows optimal timing of delivery to minimise peri- and postpartum materno-foetal complications. Glucokinase (GCK)-MODY causes mild fasting hyperglycaemia which does not require treatment outside of pregnancy. Birthweight of offspring of maternal carriers is dependent on foetal genotype; heterozygous mutation carriers are usually normal weight while genotype negative offspring are large for gestational age (600 g heavier). Affected offspring of paternal carriers may be small for gestational age (500 g lighter). Serial growth scans with measurement of the abdominal circumference indirectly differentiate foetal genotype. Measurement of cell free foetal DNA in maternal blood from the late first trimester is superior to traditionally used ultrasound to distinguish foetal genotype. Cost and accessibility may limit its use.

How do I diagnose Maturity Onset Diabetes of the Young in my patients?

Maturity Onset Diabetes of the Young (MODY) is a monogenic form of diabetes diagnosed in young individuals that lack the typical features of type 1 and type 2 diabetes. The genetic subtype of MODY determines the most effective treatment and this is the driver for MODY genetic testing in diabetes populations. Despite the obvious clinical and health economic benefits, MODY is significantly underdiagnosed with the majority of patients being inappropriately managed as having type 1 or type 2 diabetes. Low detection rates result from the difficulty in identifying patients with a likely diagnosis of MODY from the high background population of young onset type 1 and type 2 diabetes, compounded by the lack of MODY awareness and education in diabetes care physicians. MODY diagnosis can be improved through (1) access to education and training, (2) the use of sensitive and specific selection criteria based on accurate prediction models and biomarkers to identify patients for testing, (3) the development and mainstream implementation of simple criteria-based selection pathways applicable across a range of healthcare settings and ethnicities to select the most appropriate patients for genetic testing and (4) the correct use of next generation sequencing technology to provide accurate and comprehensive testing of all known MODY and monogenic diabetes genes. The creation and public sharing of educational materials, clinical and scientific best practice guidelines and genetic variants will help identify the missing patients so they can benefit from the more effective clinical care that a genetic diagnosis brings.

Variable phenotypes of individual and family monogenic cases with hyperinsulinism and diabetes: a systematic review

Maturity-Onset Diabetes of the Youth (MODY) diabetes remains commonly misdiagnosed. A monogenic form should be suspected in individuals presenting hyperinsulinemic hypoglycemia (HH) associated with, either later development of MODY (hypoglycemia-remission-diabetes sequence), or with first/second-degree family history of diabetes. Herein, we aimed to describe this individual or family monogenic association between HH and diabetes, and identify potential genotype-phenotype correlations. We conducted a systematic review of 26 studies, including a total of 67 patients with this association resulting from variants in GCK (n = 5 cases), ABCC8 (n = 29), HNF1A (n = 5), or HNF4A (n = 28). A family history of hypoglycemia and/or diabetes was present in 91% of cases (61/67). Median age at first hypoglycemia was 24 h after birth. Diazoxide was initiated in 46 children (46/67-69%); responsiveness was found in 91% (42/46). Median HH duration was three years (1 day-25 years). Twenty-three patients (23/67-34%) later developed diabetes (median age: 13 years; range: 8-48); more frequently in those untreated with diazoxide. This association was most commonly inherited in an autosomal dominant manner (43/48-90%). Some genes were associated with less severe initial hypoglycemia (HNF1A), shorter duration of HH (HNF4A), and more maternal (ABCC8) or paternal (HNF4A) transmission. This study illustrates that the same genotype can give a biphasic phenotype in the same person or a reverse phenotype in the same family. Wider awareness of this association is necessary in pediatrics to establish annual monitoring of patients who have presented HH, and during maternity to screen diabetes and optimize genetic counseling and management of pregnancy, childbirth, and the newborn.PROSPERO registration: CRD42020178265.

"Please see this man with a 69-year history of hypoglycaemia"

Mutations in the HNF4A gene are associated with hyperinsulinaemic hypoglycaemia in infants, frequently evolving into relative deficiency of insulin in adulthood ---as maturity onset diabetes of the young (MODY). A 69-year-old male with a strong family history of adult-onset diabetes was referred with lifelong hypoglycaemia, found to be due to a pathogenic HNF4A mutation. HbA1c levels were low, continuous glucose monitoring demonstrated frequent low glucose events in the early morning, and he was successfully treated with diazoxide. This case represents a new phenotype of a known mutation associated more commonly with MODY. The same mutation in one family led to profoundly different manifestations. Genetic causes of hyperinsulinaemic hypoglycaemia can present late in life and identifying such cases is important to allow the correct treatment to be established.

Maturity Onset Diabetes of the Young-New Approaches for Disease Modelling

Maturity-onset diabetes of the young (MODY) is a genetically heterogeneous group of monogenic endocrine disorders that is characterised by autosomal dominant inheritance and pancreatic β-cell dysfunction. These patients are commonly misdiagnosed with type 1 or type 2 diabetes, as the clinical symptoms largely overlap. Even though several biomarkers have been tested none of which could be used as single clinical discriminator. The correct diagnosis for individuals with MODY is of utmost importance, as the applied treatment depends on the gene mutation or is subtype-specific. Moreover, in patients with HNF1A-MODY, additional clinical monitoring can be included due to the high incidence of vascular complications observed in these patients. Finally, stratification of MODY patients will enable better and newer treatment options for MODY patients, once the disease pathology for each patient group is better understood. In the current review the clinical characteristics and the known disease-related abnormalities of the most common MODY subtypes are discussed, together with the up-to-date applied diagnostic criteria and treatment options. Additionally, the usage of pluripotent stem cells together with CRISPR/Cas9 gene editing for disease modelling with the possibility to reveal new pathophysiological mechanisms in MODY is discussed.

A Clinical Prediction Model to Distinguish Maturity-Onset Diabetes of the Young From Type 1 and Type 2 Diabetes in the Chinese Population

OBJECTIVE

Genetic detection for the diagnosis of maturity-onset diabetes of the young (MODY) in China has low sensitivity and specificity. Better gene detection is urgently needed to distinguish testing subjects. We proposed to use numerous and weighted clinical traits as key indicators for reasonable genetic testing to predict the probability of MODY in the Chinese population.

METHODS

We created a prediction model based on data from 306 patients, including 140 patients with MODY, 84 patients with type 1 diabetes (T1D), and 82 patients with type 2 diabetes (T2D). This model was evaluated using receiver operating characteristic curves.

RESULTS

Compared with patients with T1D, patients with MODY had higher C-peptide levels and negative antibodies, and most patients with MODY had a family history of diabetes. Different from T2D, MODY was characterized by lower body mass index and younger diagnostic age. A clinical prediction model was established to define the comprehensive probability of MODY by a weighted consolidation of the most distinguishing features, and the model showed excellent discrimination (areas under the curve of 0.916 in MODY vs T1D and 0.942 in MODY vs T2D). Further, high-sensitivity C-reactive protein, glycated hemoglobin A1c, 2-h postprandial glucose, and triglyceride were used as indicators for glucokinase-MODY, while triglyceride, high-sensitivity C-reactive protein, and hepatocellular adenoma were used as indicators for hepatocyte nuclear factor 1-α MODY.

CONCLUSION

We developed a practical prediction model that could predict the probability of MODY and provide information to identify glucokinase-MODY and hepatocyte nuclear factor 1-α MODY. These results provide an advanced and more reasonable process to identify the most appropriate patients for genetic testing.

Approach to the Patient with MODY-Monogenic Diabetes

Maturity-onset diabetes of the young, or MODY-monogenic diabetes, is a not-so-rare collection of inherited disorders of non-autoimmune diabetes mellitus that remains insufficiently diagnosed despite increasing awareness. These cases are important to efficiently and accurately diagnose, given the clinical implications of syndromic features, cost-effective treatment regimen, and the potential impact on multiple family members. Proper recognition of the clinical manifestations, family history, and cost-effective lab and genetic testing provide the diagnosis. All patients must undergo a thorough history, physical examination, multigenerational family history, lab evaluation (glycated hemoglobin A1c [HbA1c], glutamic acid decarboxylase antibodies [GADA], islet antigen 2 antibodies [IA-2A], and zinc transporter 8 [ZnT8] antibodies). The presence of clinical features with 3 (or more) negative antibodies may be indicative of MODY-monogenic diabetes, and is followed by genetic testing. Molecular genetic testing should be performed before attempting specific treatments in most cases. Additional testing that is helpful in determining the risk of MODY-monogenic diabetes is the MODY clinical risk calculator (>25% post-test probability in patients not treated with insulin within 6 months of diagnosis should trigger genetic testing) and 2-hour postprandial (after largest meal of day) urinary C-peptide to creatinine ratio (with a ≥0.2 nmol/mmol to distinguish HNF1A- or 4A-MODY from type 1 diabetes). Treatment, as well as monitoring for microvascular and macrovascular complications, is determined by the specific variant that is identified. In addition to the diagnostic approach, this article will highlight recent therapeutic advancements when patients no longer respond to first-line therapy (historically sulfonylurea treatment in many variants).

LEARNING OBJECTIVES

Upon completion of this educational activity, participants should be able to.

TARGET AUDIENCE

This continuing medical education activity should be of substantial interest to endocrinologists and all health care professionals who care for people with diabetes mellitus.

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.

Hypoglycemia and antihyperglycemic treatment in adult MODY patients - A systematic review of literature

Maturity onset diabetes of the young (MODY) is a heterogeneous group of diseases caused by a single mutation in one of the 14 genes involved in the regulation of glucose homeostasis. GCK, HNF1A, and HNF4A genes are among the most common genes affected. Expression of these genes in the key organs for defense against hypoglycemia and their participation in counter-regulation to hypoglycemia may potentially put individuals with a heterozygous mutation in these genes at increased risk for hypoglycemia. In HNF4A-MODY and HNF1A-MODY patients, normal or even increased insulin sensitivity together with glucose-independent mechanism of action of the first-line therapy - sulphonylurea derivatives - often leads to hypoglycemia, even at the much lower dose used in type 2 diabetes. This review aims to analyze clinical studies and case reports concerning hypoglycemia associated with antihyperglycemic treatment in adult MODY patients.

Role of hepatocyte nuclear factor 4-alpha in gastrointestinal and liver diseases

Hepatocyte nuclear factor 4-alpha (HNF4α) is a highly conserved member of nuclear receptor superfamily of ligand-dependent transcription factors that is expressed in liver and gastrointestinal organs (pancreas, stomach, and intestine). In liver, HNF4α is best known for its role as a master regulator of liver-specific gene expression and essential for adult and fetal liver function. Dysregulation of HNF4α expression has been associated with many human diseases such as ulcerative colitis, colon cancer, maturity-onset diabetes of the young, liver cirrhosis, and hepatocellular carcinoma. However, the precise role of HNF4α in the etiology of these human pathogenesis is not well understood. Limited information is known about the role of HNF4α isoforms in liver and gastrointestinal disease progression. There is, therefore, a critical need to know how disruption of the expression of these isoforms may impact on disease progression and phenotypes. In this review, we will update our current understanding on the role of HNF4α in human liver and gastrointestinal diseases. We further provide additional information on possible use of HNF4α as a target for potential therapeutic approaches.

How Recent Advances in Genomics Improve Precision Diagnosis and Personalized Care of Maturity-Onset Diabetes of the Young

PURPOSE OF REVIEW

Non-autoimmune monogenic diabetes (MD) in young people shows a broad spectrum of clinical presentations, which is largely explained by multiple genetic etiologies. This review discusses how the application of state-of-the-art genomics research to precision diagnosis of MD, particularly the various subtypes of maturity-onset diabetes of the young (MODY), has increasingly informed diabetes precision medicine and patient care throughout life.

RECENT FINDINGS

Due to extended genetic and clinical heterogeneity of MODY, diagnosis approaches based on next-generation sequencing have been worthwhile to better ascribe a specific subtype to each patient with young-onset diabetes. This guides the best appropriate treatment and clinical follow-up. Early etiological diagnosis of MD and individualized treatment are essential for achieving metabolic targets and avoiding long-term diabetes complications, as well as for drastically decreasing the financial and societal burden of diabetes-related healthcare. Genomic medicine-based practices help to optimize long-term clinical follow-up and patient care management.

Frequency and Characteristics of MODY 1 (HNF4A Mutation) and MODY 5 (HNF1B Mutation): Analysis From the DPV Database

OBJECTIVE

To characterize the initial presentation and clinical course of patients with hepatocyte nuclear factor (HNF) 4A‒ and HNF1B‒MODY in a multinational registry.

DESIGN, SETTING, AND PARTICIPANTS

Within the Diabetes Patienten Verlaufsdokumentation (DPV) registry, 44 patients with HNF4A- and 35 patients with HNF1B-MODY were characterized and compared with patients <20 years old with type 1 diabetes (T1D)/type 2 diabetes (T2D).

MAIN OUTCOME MEASURE

Clinical and laboratory parameters, therapy, metabolic control, and extrapancreatic symptoms in patients with HNF1B-MODY.

RESULTS

Patients with both MODY types were significantly older than patients with T1D at diagnosis (HNF4A, 13.8 years, and HNF1B, 13.5 years, vs T1D, 8.8 years; P < 0.0001). Mean C-peptide at diagnosis was higher for HNF4A-MODY than for T1D (1.8 vs 0.9 ng/mL; P < 0.01); 36.4% of patients with HNF4A-MODY and 65.7% of patients with HNF1B-MODY were treated with insulin, whereas 20.5% and 8.6% received oral antidiabetics only (P < 0.05 and P < 0.01 vs T2D). At the most recent visit, glycated hemoglobin levels were lower in HNF4A- and HNF1B-MODY (mean, 6.5% and 6.1%) than in T1D (7.9%; P < 0.0001). In 40% of patients with HNF1B-MODY, extrapancreatic symptoms were reported. Several clinical predictors previously described to differentiate between MODY and T1D or T2D were revalidated by logistic regression analyses in this cohort.

CONCLUSION

The DPV registry enabled us to precisely characterize phenotype and treatment in these two rare MODY types. Although phenotype of HNF4A- and HNF1B-MODY showed distinct differences from those of T1D and T2D, 38% of patients were initially misclassified as having T1D or T2D.