Cause Of Permanent Neonatal Diabetes Mellitus Research Articles

Clinical Characteristics, Molecular Features, and Long-Term Follow-Up of 15 Patients with Neonatal Diabetes: A Single-Centre Experience

Background: Diabetes diagnosed within the first 6 months of life is defined as neonatal diabetes mellitus (NDM). Mutations in the KCNJ11, ABCC8, and INS genes are the most common cause of permanent NDM. In populations with a high rate of consanguinity, Wolcott-Rallison syndrome caused by biallelic EIF2AK3 mutations is common. Methods: We studied the clinical characteristics and underlying genetic cause of disease in 15 individuals with diabetes onset before 6 months of age as defined by sustained hyperglycaemia requiring insulin treatment. Patients who had a remission of the diabetes, defined by a normal blood glucose and HbA1c value without insulin or sulphonylurea (SU) treatment, within the first 18 months of life were classified as having transient NDM (TNDM). Results: We report 15 patients with NDM from 14 unrelated families, including 10 with reported parental consanguinity. 1/15 patients had a remission of diabetes, leading to a diagnosis of TNDM. Mutations were detected in 80% (n = 12/15) of the cohort (ABCC8 [n = 4], PTF1A-distal enhancer [n = 3], KCNJ11 [n = 2], EIF2AK3 [n = 1], INS [n = 1], and SLC19A2 [n = 1]). All cases were initially treated with multiple dose insulin injections. One patient with an ABCC8 mutation transitioned from insulin to SU resulting in improved metabolic control at the age of 20 years. Conclusion: Although the number of individuals born to consanguineous parents was considerably high in this cohort, KATP channel mutations (ABCC8/KCNJ11) were more common than EIF2AK3 mutations (n = 6 vs. n = 1). Genetic analyses should be performed in all NDM cases due to the potential impact on treatment and prognosis.

The clinical and genetic characteristics of permanent neonatal diabetes (PNDM) in the state of Qatar.

BackgroundNeonatal diabetes mellitus (NDM) is a rare condition that occurs within the first six months of life. Permanent NDM (PNDM) is caused by mutations in specific genes that are known for their expression at early and/or late stages of pancreatic beta‐ cell development, and are either involved in beta‐cell survival, insulin processing, regulation, and release. The native population in Qatar continues to practice consanguineous marriages that lead to a high level of homozygosity. To our knowledge, there is no previous report on the genomics of NDM among the Qatari population. The aims of the current study are to identify patients with NDM diagnosed between 2001 and 2016, and examine their clinical and genetic characteristics.MethodsTo calculate the incidence of PNDM, all patients with PNDM diagnosed between 2001 and 2016 were compared to the total number of live births over the 16‐year‐period. Whole Genome Sequencing (WGS) was used to investigate the genetic etiology in the PNDM cohort.ResultsPNDM was diagnosed in nine (n = 9) patients with an estimated incidence rate of 1:22,938 live births among the indigenous Qatari. Seven different mutations in six genes (PTF1A, GCK, SLC2A2, EIF2AK3, INS, and HNF1B) were identified. In the majority of cases, the genetic etiology was part of a previously identified autosomal recessive disorder. Two novel de novo mutations were identified in INS and HNF1B.ConclusionQatar has the second highest reported incidence of PNDM worldwide. A majority of PNDM cases present as rare familial autosomal recessive disorders. Pancreas associated transcription factor 1a (PTF1A) enhancer deletions are the most common cause of PNDM in Qatar, with only a few previous cases reported in the literature.

Identification of novel variants in neonatal diabetes mellitus genes in Egyptian patients with permanent NDM

Neonatal diabetes mellitus (NDM) is a monogenic form of diabetes resulting from mutations in more than 20 different genes encoding proteins playing a key role in the normal function of the pancreatic beta-cell. Mutations in the genes encoding the ATP-sensitive potassium channel, ABCC8, and KCNJ11 and insulin (INS) gene are the most common causes of NDM; however, in consanguineous populations, EIF2AK3 mutations are more common. Identification of the causative mutations by genetic testing is critical for appropriate management and to guide genetic counseling. To determine the genetic etiology of NDM in diabetic neonates and infants diagnosed before the age of 1 year and to describe their phenotype/genotype characteristics, DNA sequencing of coding regions and intronic boundaries of ABCC8, KCNJ11, INS, and EIF2AK3 genes was undertaken in 20 patients. Further, targeted next-generation sequencing was performed for other genes known to cause NDM. ABCC8 mutations were found in two patients (10%), with compound heterozygous mutations (p.N131 K/p.R598*) in one patient and a homozygous mutation (p.R1554Q) in the another patient. Heterozygous p.A174G and p.V59M mutations of KCNJ11 were identified in two patients (10%), and homozygous EIF2AK3 mutations were identified in two further patients (p.T905fs and p.R653T) (10%). No INS mutations were identified. Further testing identified a SLC19A2 mutation (p.W387*) in one patient (5%) and the same homozygous GCK mutation in two siblings (p.A188T). ABCC8, KCNJ11, and EIF2AK3 mutations were the main genetic causes of permanent NDM among Egyptian neonates.

A Genotype-First Approach for Clinical and Genetic Evaluation of Wolcott-Rallison Syndrome in a Large Cohort of Iranian Children With Neonatal Diabetes.

Wolcott-Rallison syndrome (WRS) is an extremely rare autosomal recessive condition, characterized by permanent neonatal diabetes mellitus (PNDM) associated with skeletal dysplasia, growth retardation and liver dysfunction. WRS is caused by biallelic mutations in the gene encoding eukaryotic translation initiation factor 2alpha kinase 3 (EIF2AK3). As part of a comprehensive study on clinical and genetic investigation of neonatal diabetes in an Iranian population, 60 unrelated Iranian subjects referred with PNDM were analyzed. All the probands were screened for KCNJ11, INS, ABCC8 and EIF2AK3 using a polymerase chain reaction-based sequencing approach. We identified 9 different variants in EIF2AK3 in 11 unrelated Iranian probands, of which 5 variants were shown to be novel and not reported previously. The diagnosis of WRS was made by molecular genetic testing and confirmed by clinical re-evaluation of the subjects. Clinical follow up of the affected individuals shows that in at least some of them, PNDM was associated with short stature, failure to thrive, neurodevelopmental delay, epilepsy and hepatic and renal dysfunction. There was a strong family history of neonatal diabetes in the families of the probands with a high mortality rate. WRS is a common cause of PNDM in children of consanguineous parents. Furthermore, clinical diagnosis of WRS would have been delayed or possibly missed without genetic testing because this study shows that the associated features of WRS might be obscured by a diagnosis of PNDM. Therefore EIF2AK3 should be considered for any infant and young child with PNDM, particularly if the parents are related.

A new compound heterozygosis for inactivating mutations in the glucokinase gene as cause of permanent neonatal diabetes mellitus (PNDM) in double-first cousins.

BackgroundPermanent neonatal diabetes mellitus (PNDM) is a rare disorder, characterized by uncontrolled hyperglycemia diagnosed during the first 6 months of life. In general, PNDM has a genetic origin and most frequently it results from heterozygous mutations in KCNJ11, INS and ABCC8 genes. Homozygous or compound heterozygous inactivating mutations in GCK gene as cause of PNDM are rare. In contrast, heterozygosis for GCK inactivating mutations is frequent and results in the maturity-onset diabetes of young (MODY), manifested by a mild fasting hyperglycemia usually detected later in life. Therefore, as an autosomal recessive disorder, GCK-PNDM should be considered in families with history of glucose intolerance or MODY in first relatives, especially when consanguinity is suspected.ResultsHere we describe two patients born from non-consanguineous parents within a family. They presented low birth weight with persistent hyperglycemia during the first month of life. Molecular analyses for KCNJ11,INS, ABCC8 did not show any mutation. GCK gene sequencing, however, revealed that both patients were compound heterozygous for two missense combined in a novel GCK-PNDM genotype. The p.Asn254His and p.Arg447Gly mutations had been inherited from their mothers and fathers, respectively, as their mothers are sisters and their fathers are brothers. Parents had been later diagnosed as having GCK-MODY.ConclusionsMutations’ in silico analysis was carried out to elucidate the role of the amino acid changes on the enzyme structure. Both p.Asn254His and p.Arg447Gly mutations appeared to be quite damaging. This is the first report of GCK-PNDM in a Brazilian family.

Permanent neonatal diabetes mellitus: prevalence and genetic diagnosis in the SEARCH for Diabetes in Youth Study.

Neonatal diabetes mellitus (NDM) is defined as diabetes with onset before 6 months of age. Nearly half of individuals with NDM are affected by permanent neonatal diabetes mellitus (PNDM). Mutations in KATP channel genes (KCNJ11, ABCC8) and the insulin gene (INS) are the most common causes of PNDM. To estimate the prevalence of PNDM among SEARCH for Diabetes in Youth (SEARCH) study participants (2001-2008) and to identify the genetic mutations causing PNDM. SEARCH is a multicenter population-based study of diabetes in youth <20 yr of age. Participants diagnosed with diabetes before 6 months of age were invited for genetic testing for mutations in the KCNJ11, ABCC8, and INS genes. Of the 15,829 SEARCH participants with diabetes, 39 were diagnosed before 6 months of age. Thirty-five of them had PNDM (0.22% of all diabetes cases in SEARCH), 3 had transient neonatal diabetes that had remitted by 18 months and 1 was unknown. The majority of them (66.7%) had a clinical diagnosis of type1 diabetes by their health care provider. Population prevalence of PNDM in youth <20 yr was estimated at 1 in 252 000. Seven participants underwent genetic testing; mutations causing PNDM were identified in five (71%), (two KCNJ11, three INS). We report the first population-based frequency of PNDM in the US based on the frequency of PNDM in SEARCH. Patients with NDM are often misclassified as having type1 diabetes. Widespread education is essential to encourage appropriate genetic testing and treatment of NDM.

Permanent neonatal diabetes: different aetiology in Arabs compared to Europeans

ObjectiveMutations in the KCNJ11 and ABCC8 genes that encode the pancreatic KATP channel are the commonest cause of permanent neonatal diabetes mellitus (PNDM). The authors aimed to define the genetic...

Permanent neonatal diabetes mellitus - the importance of diabetes differential diagnosis in neonates and infants

The differential diagnosis of various types and forms of diabetes is of great practical importance. This is particularly true for monogenic disease forms, where some spectacular applications of pharmacogenetics have recently been described. For many years the distinct character of diabetes diagnosed in the first weeks and months of life remained unnoticed. The results of the search for type 1 diabetes-related autoantibodies, description of the HLA haplotypes distribution and analysis of clinical features in patients diagnosed in the first 6 months of life provided the initial evidence that the etiology of their disease might be different from that of autoimmune diabetes. Over the last decade, mutations in about a dozen of genes have been linked to the development of Permanent Neonatal Diabetes Mellitus (PNDM). The most frequent causes of PNDM are heterozygous mutations in the KCNJ11, INS and ABCC8 genes. Although PNDM is a rare phenomenon (one case in about 200,000 live births), this discovery has had a large impact on clinical practice as most carriers of KCNJ11 and ABCC8 gene mutations have been switched from insulin to oral sulphonylureas with an improvement in glycemic control. In this review we summarize the practical aspects of diabetes differential diagnosis in neonates and infants. Genetic testing should be advised in all subjects with PNDM as it may influence medical care in subjects with these monogenic forms of early onset diabetes.

Transfer from Insulin to Sulfonylurea Treatment in a Chinese Patient with Permanent Neonatal Diabetes Mellitus due to a KCNJ11 R201H Mutation

Neonatal diabetes mellitus (NDM) is a rare and specific type of diabetes which is characterized by onset of hyperglycemia within the first 6 months of life. The reported incidence of NDM is 1:300 000–400 000 in newborns [1] [2]. It is clinically classified into two groups: transient neonatal diabetes mellitus (TNDM) and permanent neonatal diabetes mellitus (PNDM). TNDM usually spontaneously resolves within the first months of life, with possible recurrence in childhood or adolescent stage. It represents 50% to 60% of cases of NDM, and is often associated with an abnormality of the imprinted region of 6q24 [1] [3]. In contrast, PNDM needs a lifelong medication. It has been recognized that heterozygous activating mutation in the KCNJ11 gene which encodes the Kir6.2 subunits of the ATP sensitive K+ channel (KATP channel) is a major cause of PNDM [1] [3]. And cases have been reported in which a better glycemic control was obtained after initiation of oral sulfonylurea treatment compared to insulin therapy [4] [5]. Here we report the first Chinese case of PNDM with a KCNJ11 R201H mutation and the successful transition from insulin injections to oral sulfonylurea therapy.

KCNJ11activating mutations in Italian patients with permanent neonatal diabetes

Permanent neonatal diabetes mellitus (PNDM) is a rare condition characterized by severe hyperglycemia constantly requiring insulin treatment from its onset. Complete deficiency of glucokinase (GCK) can cause PNDM; however, the genetic etiology is unknown in most PNDM patients. Recently, heterozygous activating mutations of KCNJ11, encoding Kir6.2, the pore forming subunit of the ATP-dependent potassium (K(ATP)) channel of the pancreatic beta-cell, were found in patients with PNDM. Closure of the K(ATP) channel exerts a pivotal role in insulin secretion by modifying the resting membrane potential that leads to insulin exocytosis. We screened the KCNJ11 gene in 12 Italian patients with PNDM (onset within 3 months from birth) and in six patients with non-autoimmune, insulin-requiring diabetes diagnosed during the first year of life. Five different heterozygous mutations were identified: c.149G>C (p.R50P), c.175G>A (p.V59M), c.509A>G (p.K170R), c.510G>C (p.K170N), and c.601C>T (p.R201C) in eight patients with diabetes diagnosed between day 3 and 182. Mutations at Arg50 and Lys170 residues are novel. Four patients also presented with motor and/or developmental delay as previously reported. We conclude that KCNJ11 mutations are a common cause of PNDM either in isolation or associated with developmental delay. Permanent diabetes of non autoimmune origin can present up to 6 months from birth in individuals with KCNJ11 and EIF2AK3 mutations. Therefore, we suggest that the acronym PNDM be replaced with the more comprehensive permanent diabetes mellitus of infancy (PDMI), linking it to the gene product (e.g., GCK-PDMI, KCNJ11-PDMI) to avoid confusion between patients with early-onset, autoimmune type 1 diabetes.