Differential diagnosis of type 1 diabetes: which genetic syndromes need to be considered?

Genetic perspectives on childhood monogenic diabetes: Diagnosis, management, and future directions

Monogenic diabetes is caused by one or even more genetic variations, which may be uncommon yet have a significant influence and cause diabetes at an early age. Monogenic diabetes affects 1 to 5% of children, and early detection and gene-tically focused treatment of neonatal diabetes and maturity-onset diabetes of the young can significantly improve long-term health and well-being. The etiology of monogenic diabetes in childhood is primarily attributed to genetic variations affecting the regulatory genes responsible for beta-cell activity. In rare instances, mutations leading to severe insulin resistance can also result in the development of diabetes. Individuals diagnosed with specific types of monogenic diabetes, which are commonly found, can transition from insulin therapy to sulfonylureas, provided they maintain consistent regulation of their blood glucose levels. Scientists have successfully devised materials and methodologies to distinguish individuals with type 1 or 2 diabetes from those more prone to monogenic diabetes. Genetic screening with appropriate findings and interpretations is essential to establish a prognosis and to guide the choice of therapies and management of these interrelated ailments. This review aims to design a comprehensive literature summarizing genetic insights into monogenetic diabetes in children and adolescents as well as summarizing their diagnosis and mana-gement.

Role of Actionable Genes in Pursuing a True Approach of Precision Medicine in Monogenic Diabetes

Monogenic diabetes is a genetic disorder caused by one or more variations in a single gene. It encompasses a broad spectrum of heterogeneous conditions, including neonatal diabetes, maturity onset diabetes of the young (MODY) and syndromic diabetes, affecting 1-5% of patients with diabetes. Some of these variants are harbored by genes whose altered function can be tackled by specific actions ("actionable genes"). In suspected patients, molecular diagnosis allows the implementation of effective approaches of precision medicine so as to allow individual interventions aimed to prevent, mitigate or delay clinical outcomes. This review will almost exclusively concentrate on the clinical strategy that can be specifically pursued in carriers of mutations in "actionable genes", including ABCC8, KCNJ11, GCK, HNF1A, HNF4A, HNF1B, PPARG, GATA4 and GATA6. For each of them we will provide a short background on what is known about gene function and dysfunction. Then, we will discuss how the identification of their mutations in individuals with this form of diabetes, can be used in daily clinical practice to implement specific monitoring and treatments. We hope this article will help clinical diabetologists carefully consider who of their patients deserves timely genetic testing for monogenic diabetes.

Epidemiology, genetic landscape and classification of childhood diabetes mellitus in the State of Qatar

AIMS/INTRODUCTION

To study the epidemiology, genetic landscape and causes of childhood diabetes mellitus in the State of Qatar.

MATERIALS AND METHODS

All patients (aged 0-18 years) with diabetes mellitus underwent biochemical, immunological and genetic testing. American Diabetes Association guidelines were used to classify types of diabetes mellitus. The incidence and prevalence of all the different types of diabetes mellitus were calculated.

RESULTS

Total number of children with diabetes mellitus was 1,325 (type 1 n = 1,096, ≥1 antibody; type 2 n = 104, type 1B n = 53; maturity onset diabetes of the young n = 20; monogenic autoimmune n = 4; neonatal diabetes mellitus n = 10;, syndromic diabetes mellitus n = 23; and double diabetes mellitus n = 15). The incidence and prevalence of type 1 diabetes were 38.05 and 249.73 per 100,000, respectively, and for type 2 were 2.51 and 23.7 per 100,000, respectively. The incidence of neonatal diabetes mellitus was 34.4 per 1,000,000 live births, and in indigenous Qataris the incidence was 43.6 per 1,000,000 live births. The prevalence of type 1 diabetes and type 2 diabetes in Qatari children was double compared with other nationalities. The prevalence of maturity onset diabetes of the young in Qatar was 4.56 per 100,000.

CONCLUSIONS

This is the first prospective and comprehensive study to document the epidemiology and genetic landscape of childhood diabetes mellitus in this region. Qatar has the fourth highest incidence of type 1 diabetes mellitus, with the incidence and prevalence being higher in Qatari compared with non-Qatari. The prevalence of type 2 diabetes mellitus is also higher in Qatar than in Western countries. The incidence of neonatal diabetes mellitus is the second highest in the world. GCK is the most common form of maturity onset diabetes of the young, and a large number of patients have type 1B diabetes mellitus.

Urinary Tract Involvement in Wolfram Syndrome: A Narrative Review

Wolfram Syndrome (WS) is a rare neurodegenerative disease with autosomal recessive inheritance and characterized by juvenile onset, non-autoimmune diabetes mellitus and later followed by optic atrophy leading to blindness, diabetes insipidus, hearing loss, and other neurological and endocrine dysfunctions. A wide spectrum of neurodegenerative abnormalities affecting the central nervous system has been described. Among these complications, neurogenic bladder and urodynamic abnormalities also deserve attention. Urinary tract dysfunctions (UTD) up to end stage renal disease are a life-threatening complication of WS patients. Notably, end stage renal disease is reported as one of the most common causes of death among WS patients. UTD have been also reported in affected adolescents. Involvement of the urinary tract occurs in about 90% of affected patients, at a median age of 20 years and with peaks at 13, 21 and 33 years. The aim of our narrative review was to provide an overview of the most important papers regarding urological impairment in Wolfram Syndrome. A comprehensive search on PubMed including Wolfram Syndrome and one or more of the following terms: chronic renal failure, bladder dysfunction, urological aspects, and urinary tract dysfunction, was done. The exclusion criteria were studies not written in English and not including urinary tract dysfunction deep evaluation and description. Studies mentioning general urologic abnormalities without deep description and/or follow-up were not considered. Due to the rarity of the condition, we considered not only papers including pediatric patients, but also papers with pediatric and adult case reports

Genetic syndromes with diabetes: A systematic review

Previous reviews and clinical guidelines have identified 10-20 genetic syndromes associated with diabetes, but no systematic review has been conducted to date. We provide the first comprehensive catalog for syndromes with diabetes mellitus. We conducted a systematic review of MEDLINE, Embase, CENTRAL, PubMed, OMIM, and Orphanet databases for case reports, case series, and observational studies published between 1946 and January 15, 2020, that described diabetes mellitus in adults and children with monogenic or chromosomal syndromes. Our literature search identified 7,122 studies, of which 160 fulfilled inclusion criteria. Our analysis of these studies found 69 distinct diabetes syndromes. Thirty (43.5%) syndromes included diabetes mellitus as a cardinal clinical feature, and 56 (81.2%) were fully genetically elucidated. Sixty-three syndromes (91.3%) were described more than once in independent case reports, of which 59 (93.7%) demonstrated clinical heterogeneity. Syndromes associated with diabetes mellitus are more numerous and diverse than previously anticipated. While knowledge of the syndromes is limited by their low prevalence, future reviews will be needed as more cases are identified. The genetic etiologies of these syndromes are well elucidated and provide potential avenues for future gene identification efforts, aid in diagnosis and management, gene therapy research, and developing personalized medicine treatments.

Clinical and exome sequencing findings in seven children with Bardet-Biedl syndrome from Turkey

BACKGROUND

Bardet-Biedl syndrome (BBS) is a very-rare autosomal recessive genetic disorder with severe multisystem manifestations. Genetic testing plays an important role in the early diagnosis of the disease. In this study, while trying to elucidate the genetic etiology of seven individuals with clinical BBS diagnosis from six different families, we also aimed to examine the distribution of BBS variations in this region of Turkey.

METHODS AND MATERIALS

Exome sequencing analysis is performed for clinically diagnosed patients with BBS in the present study followed by parental segregation. The unreported and previously described clinical features are presented.

RESULTS

Homozygous variants, four of which are unreported, in BBS-related genes (BBS5 [c.682-2A > G], MKKS [c.775del], BBS7 [c.849+1G > T], BBS9 [c.965G > A], BBS10 [c.145C > T], LZTFL1[c.384G > A]) are detected for all the seven individuals included in the study. The most common clinical finding is polydactyly followed by renal anomalies. The clinical features not previously described are correlated to the unreported variant.

CONCLUSIONS

In this study, exome sequencing findings are discussed and four previously unreported disease-associated variants are described including the fifth BBS-implicated LZTFL1 change and possible genotype-phenotype correlation is described.

Review of current status of molecular diagnosis and characterization of monogenic diabetes mellitus: a focus on next-generation sequencing

Introduction: Monogenic diabetes is a subset of diabetes characterized by the presence of single-gene mutations and includes neonatal diabetes mellitus and maturity-onset diabetes of the young. Due to the genetic etiology of monogenic diabetes, molecular genetic testing can be used for diagnosis and classification.Areas covered: In addition to first-generation molecular analyses, many large clinical laboratories are transitioning to multiplexed next-generation sequencing panels to simultaneously assess patients for several of the most common genetic mutations seen in monogenic diabetes. With expanded development and adoption of next-generation sequencing panels, particularly in reference to laboratory settings, diagnostic testing for monogenic diabetes has the potential to be more accessible to the patient population.Expert opinion: Although molecular diagnostic testing is becoming increasingly prevalent, it is crucial to identify patients most likely to benefit from molecular testing versus those whose disease can be diagnosed and characterized with more traditional, less costly laboratory analyses. The continuous evolution of clinical molecular testing will be echoed in the clinical laboratory analysis of monogenic diabetes and continue to improve the diagnostic capabilities for monogenic diabetes mellitus.

Evidence of retinal degeneration in Wolfram syndrome

PURPOSE

Wolfram syndrome is characterized by early onset diabetes mellitus, diabetes insipidus, deafness, and optic atrophy, but retinal degeneration has not been described as a major component of the phenotype. We present two cases with Wolfram syndrome and evidence of retinal degeneration.

MATERIALS AND METHODS

Observational case series. Patients underwent complete ocular examinations as well as retinal imaging and electroretinography.

RESULTS

Both patients had electroretinographic evidence of retinal dysfunction/degeneration in addition to optic atrophy with an otherwise normal-appearing retina.

CONCLUSIONS

Some patients with Wolfram syndrome have a mild retinal degeneration that may be a manifestation of the neuronal involvement that is present in this condition.

Monogenic Diabetes in Children and Adolescents: Recognition and Treatment Options

PURPOSE OF REVIEW

We provide a review of monogenic diabetes in young children and adolescents with a focus on recognition, management, and pharmacological treatment.

RECENT FINDINGS

Monogenic forms of diabetes account for approximately 1-2% of diabetes in children and adolescents, and its incidence has increased in recent years due to greater awareness and wider availability of genetic testing. Monogenic diabetes is due to single gene defects that primarily affect beta cell function with more than 30 different genes reported. Children with antibody-negative, C-peptide-positive diabetes should be evaluated and genetically tested for monogenic diabetes. Accurate genetic diagnosis impacts treatment in the most common types of monogenic diabetes, including the use of sulfonylureas in place of insulin or other glucose-lowering agents or discontinuing pharmacologic treatment altogether. Diagnosis of monogenic diabetes can significantly improve patient care by enabling prediction of the disease course and guiding appropriate management and treatment.

Genetics of type 1 diabetes

Type 1 diabetes (T1D) results from immune-mediated loss of pancreatic beta cells leading to insulin deficiency. It is the most common form of diabetes in children, and its incidence is on the rise. This article reviews the current knowledge on the genetics of T1D. In particular, we discuss the influence of HLA and non-HLA genes on T1D risk and disease progression through the preclinical stages of the disease, and the development of genetic scores that can be applied to disease prediction. Racial/ethnic differences, challenges and future directions in the genetics of T1D are also discussed.

Glucokinase mutations in pediatric patients with impaired fasting glucose

AIMS

Our aim was to detect the frequency of glucokinase (GCK) gene mutations in a cohort of patients with impaired fasting glucose and to describe the clinical manifestations of identified variants. We also aimed at predicting the effect of the novel missense mutations by computational approach.

METHODS

Overall 100 unrelated Italian families with impaired fasting glucose were enrolled and subdivided into two cohorts according to strict and to mild criteria for diagnosis of maturity-onset diabetes of the young (MODY). GCK gene sequencing was performed in all participants.

RESULTS

Fifty-three Italian families with 44 different mutations affecting the GCK and co-segregating with the clinical phenotype of GCK/MODY were identified. All mutations were in heterozygous state. In Sample 1, GCK defects were found in 32/36 (88.9%) subjects selected with strict MODY diagnostic criteria, while in Sample 2 GCK defects were found in 21/64 (32.8%) subjects selected with mild MODY diagnostic criteria.

CONCLUSIONS

Our study enlarged the wide spectrum of GCK defects by adding 9 novel variants. The application of strict recruitment criteria resulted in 88.9% incidence of GCK/MODY, which confirmed it as the commonest form of MODY in the Italian population. In order to avoid misdiagnosis of GCK/MODY, it could be useful to perform molecular screening even if one or more clinical parameters for the diagnosis of MODY are missing. Computational analysis is useful to understand the effect of GCK defect on protein functionality, especially when the novel identified variant is a missense mutation and/or parents' DNA is not available.

Genetic Testing for Wolfram Syndrome Mutations in a Sample of 71 Patients with Hereditary Optic Neuropathy and Negative Genetic Test Results for OPA1/OPA3/LHON

In this study, the authors present a sample of 71 patients with hereditary optic neuropathy and negative genetic test results for OPA1/OPA3/LHON. All of these patients later underwent genetic testing to rule out WFS. As a result, 53 patients (74.7%) were negative and 18 patients (25.3%) were positive for some type of mutation or variation in the WFS gene. The authors believe that this study is interesting because it shows that a sizeable percentage (25.3%) of patients with hereditary optic 25 neuropathy and negative genetic test results for OPA1/OPA3/LHON had WFS mutations or variants.

Diabetes mellitus in neonates and infants: genetic heterogeneity, clinical approach to diagnosis, and therapeutic options

Over the last decade, we have witnessed major advances in the understanding of the molecular basis of neonatal and infancy-onset diabetes. It is now widely accepted that diabetes presenting before 6 months of age is unlikely to be autoimmune type 1 diabetes. The vast majority of such patients will have a monogenic disorder responsible for the disease and, in some of them, also for a number of other associated extrapancreatic clinical features. Reaching a molecular diagnosis will have immediate clinical consequences for about half of affected patients, as identification of a mutation in either of the two genes encoding the ATP-sensitive potassium channel allows switching from insulin injections to oral sulphonylureas. It also facilitates genetic counselling within the affected families and predicts clinical prognosis. Importantly, monogenic diabetes seems not to be limited to the first 6 months but extends to some extent into the second half of the first year of life, when type 1 diabetes is the more common cause of diabetes. From a scientific perspective, the identification of novel genetic aetiologies has provided important new knowledge regarding the development and function of the human pancreas.

A novel ALMS1 splice mutation in a non-obese juvenile-onset insulin-dependent syndromic diabetic patient

Insulin-dependent juvenile-onset diabetes may occur in the context of rare syndromic presentations suggesting monogenic inheritance rather than common multifactorial autoimmune type 1 diabetes. Here, we report the case of a Lebanese patient diagnosed with juvenile-onset insulin-dependent diabetes presenting ketoacidosis, early-onset retinopathy with optic atrophy, hearing loss, diabetes insipidus, epilepsy, and normal weight and stature, who later developed insulin resistance. Despite similarities with Wolfram syndrome, we excluded the WFS1 gene as responsible for this disease. Using combined linkage and candidate gene study, we selected ALMS1, responsible for Alström syndrome, as a candidate gene. We identified a novel splice mutation in intron 18 located 3 bp before the intron-exon junction (IVS18-3T>G), resulting in exon 19 skipping and consequent frameshift generating a truncated protein (V3958fs3964X). The clinical presentation of the patient significantly differed from typical Alström syndrome by the absence of truncal obesity and short stature, and by the presence of ketoacidotic insulin-dependent diabetes, optic atrophy and diabetes insipidus. Our observation broadens the clinical spectrum of Alström syndrome and suggests that ALMS1 mutations may be considered in patients who initially present with an acute onset of insulin-dependent diabetes.

Hyperglycaemia and β-cell antibodies: is it always pre-type 1 diabetes?

We describe 10-year-old girl with mild incidental hyperglycaemia, impaired glucose tolerance and GADA positivity. Family history for mild hyperglycaemia and GADA fluctuation alerted us to a possible MODY diagnosis which was confirmed by detection of GCK mutation c.626C>T; p.T209M. Weak or transient β-cell autoimmunity should not preclude genetic testing for MODY when the clinical features are suggestive.

[Diabetes mellitus: clinical presentation and differential diagnosis of hyperglycemia in childhood and adolescence]

Diabetes mellitus is one of the most common chronic diseases in childhood. Despite being a clinical and etiopathogenically heterogeneous disorder, type 1 autoimmune diabetes accounts for more than 95% of cases in children. Recent advances have meant that a growing number of patients have been assigned to other subtypes of diabetes. In such cases, the correct diagnosis is facilitated by the fact that many of these rare causes of diabetes are associated with specific clinical syndromes or may present at a certain age. Many of them are also subsidiaries of molecular diagnosis. The aim of this review is to update the current knowledge in this field of pediatric diabetes, in an attempt to determine the most accurate diagnosis and its implications on appropriate treatment and prognosis.

Cancer risk among patients hospitalized for Type 1 diabetes mellitus: a population-based cohort study in Sweden

AIMS

Type 1 diabetes mellitus (T1DM) is an autoimmune disease with potential mechanistic links to immune-related cancers. We aimed at examining the overall and specific cancer risks among hospitalized T1DM patients from the national registers in Sweden.

METHODS

A T1DM research cohort was created by identifying T1DM patients from the Hospital Discharge Register and linking them with the Cancer Registry. Standardized incidence ratios (SIRs) for subsequent cancers were calculated among patients with T1DM compared with those without T1DM.

RESULTS

Two hundred and fifty-eight cases were ascertained with subsequent cancers during the follow-up duration from 1964 to 2006, with an increased overall SIR of 1.17 (95% CI 1.04-1.33) among 24 052 T1DM patients identified at baseline. Significant excess was noted for gastric and skin (squamous cell carcinoma) cancers and for leukaemia. Increased risk of acute lymphatic leukaemia accounted for most of the variation of leukaemia risk (SIR = 5.31, 95% CI 3.32-8.05). Cancer risk varied with sex, age at first hospitalization and numbers of hospitalizations. The risk was higher in women compared with men and in those hospitalized for T1DM at age over 10 years compared with the younger patients. Higher risks were also found among those with more hospital visits.

CONCLUSION

By quantifying the variations of overall and site-specific cancer risks after T1DM, the current study provides novel associations between T1DM and subsequent cancers, the mechanisms of which remain to be established.

A novel hypomorphic PDX1 mutation responsible for permanent neonatal diabetes with subclinical exocrine deficiency

OBJECTIVE

Genes responsible for monogenic forms of diabetes have proven very valuable for understanding key mechanisms involved in beta-cell development and function. Genetic study of selected families is a powerful strategy to identify such genes. We studied a consanguineous family with two first cousins affected by neonatal diabetes; their four parents had a common ancestor, suggestive of a fully penetrant recessive mutation.

RESEARCH DESIGN AND METHODS

We performed genetic studies of the family, detailed clinical and biochemical investigations of the patients and the four parents, and biochemical and functional studies of the new mutation.

RESULTS

We found a novel mutation in the pancreatic and duodenal homeobox 1 gene (PDX1, IPF1) in the two patients, which segregated with diabetes in the homozygous state. The mutation resulted in an E178G substitution in the PDX1 homeodomain. In contrast to other reported PDX1 mutations leading to neonatal diabetes and pancreas agenesis, homozygosity for the E178G mutation was not associated with clinical signs of exocrine pancreas insufficiency. Further, the four heterozygous parents were not diabetic and displayed normal glucose tolerance. Biochemical studies, however, revealed subclinical exocrine pancreas insufficiency in the patients and slightly reduced insulin secretion in the heterozygous parents. The E178G mutation resulted in reduced Pdx1 transactivation despite normal nuclear localization, expression level, and chromatin occupancy.

CONCLUSIONS

This study broadens the clinical spectrum of PDX1 mutations and justifies screening of this gene in neonatal diabetic patients even in the absence of exocrine pancreas manifestations.

Familial association between type 1 diabetes and other autoimmune and related diseases

AIMS/HYPOTHESIS

In the era of genome-wide association studies, familial risks are used to estimate disease heritability and success in gene identification. We wanted to estimate associations between type 1 diabetes mellitus and 33 autoimmune and related diseases in parents, offspring, singleton siblings and twins.

METHODS

The availability of a Multigeneration Register in Sweden provides reliable access to families throughout the last century. The diseases in individual family members were obtained through linkage to the Hospital Discharge Register. Standardised incidence ratios (SIRs) were calculated as relative risks of contracting type 1 diabetes in family members of affected patients compared with those lacking affected family members.

RESULTS

Among a total of 450,899 patients, 21,168 were diagnosed with type 1 diabetes. Familial cases amounted to 10.3% of all type 1 diabetes patients. SIR for type 1 diabetes was 8.23 in offspring of affected parents, 11.92 in singleton siblings, 39.22 in multiplex families and 21.88 in twins; the calculated risk for monozygotic twins was 32.33. Type 1 diabetes in offspring was associated with 13 diseases in parents, including Addison's disease (SIR 2.41), asthma (1.38), coeliac disease (2.73), Graves' disease/hyperthyroidism (1.86), Hashimoto disease/hypothyroidism (2.35), pernicious anaemia (3.09), primary biliary cirrhosis (3.63), rheumatoid arthritis (2.12), sarcoidosis (1.62), systemic lupus erythematosus (2.04), ulcerative colitis (1.23) and Wegener's granulomatosis (2.12).

CONCLUSIONS/INTERPRETATION

The concordant familial risks for type 1 diabetes were high and the calculated risk for multiplex families and monozygotic twins may be explained by epistatic gene x gene or gene x environment interactions. Familial associations with several autoimmune and related diseases suggest genetic sharing and challenge to gene identification.

Diabetes mellitus, exocrine pancreatic deficiency, hypertrichosis, hyperpigmentation, and chronic inflammation: confirmation of a syndrome

Type 1 diabetes mellitus is characterized by dysregulation of the immune system leading to inflammation and selective destruction of pancreatic beta cells. Mild to moderate pancreatic exocrine insufficiency is found in patients with type 1 diabetes. Diabetes mellitus may also be part of a syndrome occasionally involving hair and skin abnormalities. We report our observations on two siblings with insulin-dependent diabetes, severe exocrine pancreatic deficiency, pigmented hypertrichotic skin patches with induration and chronic inflammation. The first sibling presented at the age of 9 months with hypertrichosis and hyperpigmentation, particularly on her back and legs and then developed diabetes mellitus at the age of 4 yr. The second sibling presented with exactly the same clinical features but at a later age of 12 yr. Both siblings had severe pancreatic exocrine deficiency with chronic persistent inflammation. Some of the clinical features in these siblings resemble those described by Prendiville et al. although our patients had additional features. The chronic inflammatory response in both siblings is highly suggestive of some form of immune dysregulation. The presence of consanguinity in the parents and similarity of clinical features in the siblings are suggestive of a novel autoimmune disorder, possibly secondary to autosomal recessive inheritance.

WFS1 mutations are frequent monogenic causes of juvenile-onset diabetes mellitus in Lebanon

Most cases of juvenile-onset diabetes (JOD) are diagnosed as type 1 diabetes (T1D), for which genetic studies conducted in outbred Caucasian populations support the concept of multifactorial inheritance. However, this view may be partly challenged in particular population settings. In view of the suggestive evidence for a high prevalence of Wolfram syndrome (WFS) in Lebanon, the phenotypic variability associated with WFS1 mutations, and the high consanguinity rate in Lebanon, we aimed to evaluate the contribution of WFS1 mutations as monogenic determinants to JOD in Lebanon. We performed a family-based genetic study, with linkage analysis followed by systematic mutation screening of WFS1 exons in all JOD probands. The study population consisted of an unbiased recruitment of all juvenile-onset insulin-dependent diabetic patients from a specialized diabetes pediatric clinic in Beirut, Lebanon. Homozygous or compound heterozygous WFS1 mutations were found in 22 of the 399 JOD probands (5.5%), resulting in WFS (17 probands) or in non-syndromic non-autoimmune diabetes mellitus (DM, five probands). These accounted for 12.1% (21/174) of probands in consanguineous families, compared with 0.4% (1/225) in non-consanguineous families. Of the 38 patients identified with homozygous or compound heterozygous WFS1 mutations, 11 (29%) had non-syndromic DM, all of whom carried a particular WFS1 mutation, WFS1(LIB), encoding a protein with an extended C-terminal domain. This mutation resulted in a delayed onset or absence of extrapancreatic features. These results underscore the major impact of population-specific factors, such as population-specific mutations and founder effects, and family structure in the genetic determinism of JOD.

A case of new mutation in maturity-onset diabetes of the young type 3 (MODY 3) responsive to a low dose of sulphonylurea

We describe a girl aged 10.5 years with hyperglycemia, whose mother and maternal father had insulin treated diabetes since adolescence. Using genetic analysis in mother and child, we identified identical new mutation of the HNF-1alpha sequence. Treatment with small doses of sulphonylurea was initiated and that therapy gave good results.