A dizygotic twin pregnancy in a MODY 3-affected woman

Maturity-onset Diabetes of the Young (MODY) in Pregnancy: A Review

Hyperglycaemia in pregnancy is one of the most common complications of pregnancy and is generally diagnosed as gestational diabetes mellitus (GDM). Nevertheless, clinical symptoms of hyperglycaemia in pregnancy in some cases do not match the clinical manifestations of GDM. It is suspected that 1-2 % of women diagnosed with GDM are misdiagnosed maturity-onset diabetes of the young (MODY). MODY often has a subclinical course; thus, it is challenging for clinicians to aptly diagnose monogenic diabetes in pregnancy. Proper diagnosis is crucial for the effective treatment of hyperglycaemia in pregnancy. Many studies revealed that misdiagnosis of MODY increases the rate of complications for both mother and fetus. This literature review reports the current knowledge regarding diagnosis, treatment, and complications of the most common types of MODY in pregnancy.

Maturity-onset diabetes of the young type 3 and premature ovarian insufficiency: chance or causality: a case report and literature review

Summary

We present the case of a 23-year-old patient with maturity-onset diabetes of the young type 3 (MODY 3) and premature ovarian insufficiency (POI). There is no known correlation between MODY 3 and POI, although POI can impair glucose metabolism, and MODY can cause microvascular complications such as POI. We did not find literature describing a correlation between these two pathologies nor did we find similar cases described in the literature.

Learning points

Maturity-onset diabetes of the young type 3 (MODY 3) is an infrequent cause of diabetes that should be considered in young patients with atypical presentation of type 1 or type 2 diabetes. MODY 3 can be associated with microvascular complications of diabetes, which is why it is important to diagnose as early as possible. Impairment of glucose metabolism has been demonstrated in patients with premature ovarian insufficiency and menopause.

Molecular diagnosis of maturity onset diabetes of the young in Iranian patients: improving management

Background

The purpose of this study is to identify the mutations of the most common form of maturity-onset diabetes of the young (MODY), also known as MODY3, in diabetic patients suspected of MODY. This can recommend appropriate medical surveillance of at-risk family members of MODY based on the genetic cause.

Methods

We analyzed the clinical course of 19 patients from 12 unrelated Iranian families with diabetes features. The coding regions and intron-exon boundaries of the hepatocyte nuclear factor 1 alpha (HNF1A) gene were studied by polymerase chain reaction (PCR) and sanger sequencing. Also, the detected mutation was analyzed by bioinformatics tools.

Results

One novel frameshift insertion mutation (p.Glu11Argfs*12) was detected in one of the probands and seven other patients of her family with the heterozygote state. The mutation is located in the exon1 of the dimerization domain of the HNF1A gene. According to the In Silico analysis, the detected mutation is predicted as a pathogenic one.

Conclusions

Differential diagnosis between MODY3 and other forms of diabetes can be considered a necessity in terms of overlapping symptoms of MODY3 with type1 or 2 diabetes. Molecular genetic testing can provide an accurate diagnosis for optimal management.

Maternal or Paternal Diabetes and Its Crucial Role in Offspring Birth Weight and MODY Diagnosis

Maturity-onset diabetes of the young (MODY) represents a heterogenous group of monogenic autosomal dominant diseases, which accounts for 1-2% of all diabetes cases. Pregnancy represents a crucial time to diagnose MODY forms due to the 50% risk of inheritance in offspring of affected subjects and the potential implications on adequate fetal weight. Not only a history of maternal diabetes may affect the birth weight of offspring, paternal diabetes should also be taken into consideration for a correct pathogenetic diagnosis. The crucial role of maternal and paternal diabetes inheritance patterns and the impact of this inherited mutation on birthweight and the MODY diagnosis was discussed.

Guidelines for the screening and diagnosis of gestational diabetes in Italy from 2010 to 2019: critical issues and the potential for improvement

AIMS

In 2010, Italian health professionals rapidly implemented the one-step screening for gestational diabetes mellitus (GDM) based on a 75 g OGTT, to comply with the diagnostic criteria proposed by the International Association of Diabetes and Pregnancy Study Groups (IADPSG). The change was promoted by the two main Italian scientific societies of diabetology, Associazione Medici Diabetologi (AMD) and Società Italiana di Diabetologia (SID), and it took just a few months for the Istituto Superiore di Sanità, together with several scientific societies, to revise the criteria and include them in the National Guidelines System. Over the last 9 years, the implementation of these guidelines has shown some benefits and some drawbacks.

METHODS

In order to evaluate the critical issues arisen from the implementation of the current Italian guidelines for the diagnosis of GDM, the studies published on this topic have been reviewed. The search was performed using the following keywords: "gestational diabetes" AND "diagnostic criteria" OR screening AND Ital*. The study is an expert opinion paper, based on the relevant scientific literature published between 2010 and 2019. The databases screened for the literature review included PubMed, MEDLINE, and Scopus.

RESULTS

The implementation of the Guidelines for Screening and Diagnosis of GDM in Italy present some strengths and some weaknesses. One of the positive aspects is that high-risk women are required to perform an OGTT early in pregnancy. By contrast, there are several aspects in need of improvement: (1) In spite of the current indications, only a minority of high-risk women perform OGTT early in pregnancy; (2) several low-risk women are screened for GDM; (3) in some low-risk women affected by GDM, the diagnosis might be missed with the application of the current guidelines; (4) there is a lack of homogeneity in the risk assessment data from different regions.

CONCLUSIONS

In order to improve the current Italian GDM guidelines, some practical solutions have been suggested.

Hepatocyte nuclear factor 1A deficiency causes hemolytic anemia in mice by altering erythrocyte sphingolipid homeostasis

The hepatocyte nuclear factor (HNF) family regulates complex networks of metabolism and organ development. Human mutations in its prototypical member HNF1A cause maturity-onset diabetes of the young (MODY) type 3. In this study, we identified an important role for HNF1A in the preservation of erythrocyte membrane integrity, calcium homeostasis, and osmotic resistance through an as-yet unrecognized link of HNF1A to sphingolipid homeostasis. HNF1A^-/- mice displayed microcytic hypochromic anemia with reticulocytosis that was partially compensated by avid extramedullary erythropoiesis at all erythroid stages in the spleen thereby excluding erythroid differentiation defects. Morphologically, HNF1A^-/- erythrocytes resembled acanthocytes and displayed increased phosphatidylserine exposure, high intracellular calcium, and elevated osmotic fragility. Sphingolipidome analysis by mass spectrometry revealed substantial and tissue-specific sphingolipid disturbances in several tissues including erythrocytes with the accumulation of sphingosine as the most prominent common feature. All HNF1A^-/- erythrocyte defects could be simulated by exposure of wild-type (WT) erythrocytes to sphingosine in vitro and attributed in part to sphingosine-induced suppression of the plasma-membrane Ca²⁺-ATPase activity. Bone marrow transplantation rescued the anemia phenotype in vivo, whereas incubation with HNF1A^-/- plasma increased the osmotic fragility of WT erythrocytes in vitro. Our data suggest a non-cell-autonomous erythrocyte defect secondary to the sphingolipid changes caused by HNF1A deficiency. Transcriptional analysis revealed 4 important genes involved in sphingolipid metabolism to be deregulated in HNF1A deficiency: Ormdl1, sphingosine kinase-2, neutral ceramidase, and ceramide synthase-5. The considerable erythrocyte defects in murine HNF1A deficiency encourage clinical studies to explore the hematological consequences of HNF1A deficiency in human MODY3 patients.

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

AIMS

HNF4A is an established cause of maturity onset diabetes of the young (MODY). Congenital hyperinsulinism can also be associated with mutations in the HNF4A gene. A dual phenotype is observed in HNF4A-MODY with hyperinsulinaemic hypoglycaemia in the neonatal period progressing to diabetes in adulthood. The nature and timing of the transition remain poorly defined. We performed an observational study to establish changes in glycaemia and insulin secretion over a 6-year period. We investigated glycaemic variability and hypoglycaemia in HNF4A-MODY using a continuous glucose monitoring system (CGMS).

METHODS

An OGTT with measurement of glucose, insulin and C-peptide was performed in HNF4A participants with diabetes mellitus (DM) (n = 14), HNF4A-IGT (n = 7) and age- and BMI-matched MODY negative family members (n = 10). Serial assessment was performed in the HNF4A-IGT cohort. In a subset of HNF4A-MODY mutation carriers (n = 10), CGMS was applied over a 72-h period.

RESULTS

There was no deterioration in glycaemic control in the HNF4A-IGT cohort. The fasting glucose-to-insulin ratio was significantly lower in the HNF4A-IGT cohort when compared to the normal control group (0.13 vs. 0.24, p = 0.03). CGMS profiling demonstrated prolonged periods of hypoglycaemia in the HNF4A-IGT group when compared to the HNF4A-DM group (432 vs. 138 min p = 0.04).

CONCLUSIONS

In a young adult HNF4A-IGT cohort, we demonstrate preserved glucose, insulin and C-peptide secretory responses to oral glucose. Utilising CGMS, prolonged periods of hypoglycaemia are evident despite a median age of 21 years. We propose a prolonged hyperinsulinaemic phase into adulthood is responsible for the notable hypoglycaemic episodes.