Maturity-onset Diabetes Of The Young Type 3 Research Articles

Generation and characterization of an induced pluripotent stem cell (iPSC) line SDQLCHi063-A from peripheral blood mononuclear cells of a patient with Maturity-onset diabetes of the young type 2 carrying GCK exon 1 deletion

Maturity-onset diabetes of the young type 2 (MODY2) is an autosomal dominant disorder caused by mutations in the GCK gene. It is characterized by a non-progressive slight increase in glycosylated hemoglobin (HbA1c), and mildly raised fasting glucose. Here, we generated an induced pluripotent stem cell line SDQLCHi063-A from a five-year-old boy with MODY2 carrying exon 1 deletion of the GCK gene (OMIM*138079). The iPSC line carries original gene mutation, expresses pluripotency markers, has normal karyotype and differentiated spontaneously in the three germ layers.

MODY Probability Calculator Is Suitable for MODY Screening in China: A Population-based Study.

Selecting appropriate individuals for genetic testing is essential due to the optimal treatment for maturity-onset diabetes of the young (MODY). However, how to effectively screen for MODY in China remains unclear. To validate the performance of current screening strategies in selecting patients with MODY based on a nationwide type 2 diabetes cohort. A panel of 14 MODY genes was analyzed from 1911 type 2 diabetes patients who were ages 15 to 35 years. Variants were evaluated according to the American College of Medical Genetics and Genomics guidelines. Based on this cohort, we simulated the 2 most frequently used screening strategies, including the traditional MODY criteria and the MODY probability calculator (MPC), to assess their ability to select patients with MODY. From a total of 1911 participants, 42 participants harbored pathogenic/likely pathogenic variants. The performance of the traditional criteria was sensitivity: 19.0%, specificity: 72.9%, positive predictive value (PPV): 1.6%, and missing rate: 81.0%. The optimal cut-off for MPC was 40.7%. Based on this cut-off value, the performance was sensitivity: 54.8%, specificity: 81.0%, PPV: 6.1%, and missing rate: 45.2%. Moreover, hemoglobin A1c, insulin treatment, and family history of diabetes have poor discrimination between MODY and young-onset type 2 diabetes. The MPC is better than traditional criteria in terms of both sensitivity and PPV. To ensure more MODY patients benefit from optimal treatment, we therefore suggest that routine genetic testing be performed on all type 2 diabetes patients who are between the ages of 15 and35 years and have MPC probability value over 40.7%.

The first case of hyperosmolar diabetic ketoacidosis in a patient diagnosed with MODY 5 (maturity-onset diabetes of the young type 5) and 17q12 microdeletion syndrome.

The first case of hyperosmolar diabetic ketoacidosis in a patient diagnosed with MODY 5 (maturity-onset diabetes of the young type 5) and 17q12 microdeletion syndrome.

Assessment of pathogenicity and functional characterization of APPL1 gene mutations in diabetic patients.

Adaptor protein, phosphotyrosine interacting with PH domain and leucine zipper 1 (APPL1) plays a crucial role in regulating insulin signaling and glucose metabolism. Mutations in the APPL1 gene have been associated with the development of maturity-onset diabetes of the young type 14 (MODY14). Currently, only two mutations [c.1655T>A (p.Leu552*) and c.281G>A p.(Asp94Asn)] have been identified in association with this disease. Given the limited understanding of MODY14, it is imperative to identify additional cases and carry out comprehensive research on MODY14 and APPL1 mutations. To assess the pathogenicity of APPL1 gene mutations in diabetic patients and to characterize the functional role of the APPL1 domain. Patients exhibiting clinical signs and a medical history suggestive of MODY were screened for the study. Whole exome sequencing was performed on the patients as well as their family members. The pathogenicity of the identified APPL1 variants was predicted on the basis of bioinformatics analysis. In addition, the pathogenicity of the novel APPL1 variant was preliminarily evaluated through in vitro functional experiments. Finally, the impact of these variants on APPL1 protein expression and the insulin pathway were assessed, and the potential mechanism underlying the interaction between the APPL1 protein and the insulin receptor was further explored. A total of five novel mutations were identified, including four missense mutations (Asp632Tyr, Arg633His, Arg532Gln, and Ile642Met) and one intronic mutation (1153-16A>T). Pathogenicity prediction analysis revealed that the Arg532Gln was pathogenic across all predictions. The Asp632Tyr and Arg633His variants also had pathogenicity based on MutationTaster. In addition, multiple alignment of amino acid sequences showed that the Arg532Gln, Asp632Tyr, and Arg633His variants were conserved across different species. Moreover, in in vitro functional experiments, both the c.1894G>T (at Asp632Tyr) and c.1595G>A (at Arg532Gln) mutations were found to downregulate the expression of APPL1 on both protein and mRNA levels, indicating their pathogenic nature. Therefore, based on the patient's clinical and family history, combined with the results from bioinformatics analysis and functional experiment, the c.1894G>T (at Asp632Tyr) and c.1595G>A (at Arg532Gln) mutations were classified as pathogenic mutations. Importantly, all these mutations were located within the phosphotyrosine-binding domain of APPL1, which plays a critical role in the insulin sensitization effect. This study provided new insights into the pathogenicity of APPL1 gene mutations in diabetes and revealed a potential target for the diagnosis and treatment of the disease.

Clinical and genetic characteristics of maturity-onset diabetes of the young type 13: A systematic review of the literature.

Maturity-onset diabetes of the young type 13 (MODY13), a rare type of monogenic diabetes, is often misdiagnosed as type 1 or type 2 diabetes. To improve early diagnosis and precise treatment, we performed a systematic review and analysis of the literature about MODY13. PubMed, Cochrane, Embase, China National Knowledge Infrastructure (CNKI), Chinese BioMedical (CBM) Literature Database, and Wanfang Database were searched using the following search terms: "MODY13," "KCNJ11 maturity-onset diabetes of the young," "KCNJ11-MODY," "maturity-onset diabetes of the young type 13," and "neonatal diabetes mellitus KCNJ11." The demography, clinical characteristics, and gene mutations of patients were expressed with descriptive statistical methods. A total of 33 reports were included in this study, including 75 patients and 28 types of mutations. Thirty-six patients were male. The mean onset age was 25.20 ± 15.26 years. The averages of recorded body mass index, glycated hemoglobin (HbA1c), and fasting C-peptide were 23.45 ± 4.56kg/m2 , 10.07 ± 1.96%, and 0.31 ± 0.23nmol/L, respectively. Most of the mutation sites were located in the cytosolic region of N- and C-terminal domains of Kir6.2. Seven patients were reported to have diabetic chronic complications. MODY13 was diagnosed later than other types of MODY and was associated with low fasting C-peptide. Mutation sites of MODY13 were mostly concentrated in N- and C-terminal intracellular domains. The majority of KCNJ11 gene mutations causing MODY 13 were from G to A. The incidence rates of chronic complications were lower than type 1 and type 2 diabetes.

Maturity-onset diabetes of the young type 7 (MODY7) and mutation in the Krüppel-like transcription factor 11 (KLF11) gene.

Maturity-onset diabetes of the young type 7 (MODY7) and mutation in the Krüppel-like transcription factor 11 (KLF11) gene.

Glucokinase Variant Proteins Are Resistant to Fasting-Induced Uridine Diphosphate Glucose-Dependent Degradation in Maturity-Onset Diabetes of the Young Type 2 Patients.

We previously reported that glucokinase undergoes ubiquitination and subsequent degradation, a process mediated by cereblon, particularly in the presence of uridine diphosphate glucose (UDP-glucose). In this context, we hereby present evidence showcasing the resilience of variant glucokinase proteins of maturity-onset diabetes of the young type 2 (MODY2) against degradation and, concomitantly, their influence on insulin secretion, both in cell lines and in the afflicted MODY2 patient. Hence, glucose-1-phodphate promotes UDP-glucose production by UDP-glucose pyrophosphorylase 2; consequently, UDP-glucose-dependent glucokinase degradation may occur during fasting. Next, we analyzed glucokinase variant proteins from MODY2 or persistent hyperinsulinemic hypoglycemia in infancy (PHHI). Among the eleven MODY2 glucokinase-mutated proteins tested, those with a lower glucose-binding affinity exhibited resistance to UDP-glucose-dependent degradation. Conversely, the glucokinaseA456V-mutated protein from PHHI had a higher glucose affinity and was sensitive to UDP-glucose-dependent degradation. Furthermore, in vitro studies involving UDP-glucose-dependent glucokinase variant proteins and insulin secretion during fasting in Japanese MODY2 patients revealed a strong correlation and a higher coefficient of determination. This suggests that UDP-glucose-dependent glucokinase degradation plays a significant role in the pathogenesis of glucose-homeostasis-related hereditary diseases, such as MODY2 and PHHI.

Hepatocyte nuclear factor 1B deletion, but not intragenic mutation, might be more susceptible to hypomagnesemia.

HNF1B syndrome is caused by defects in the hepatocyte nuclear factor 1B (HNF1B) gene, which leads to maturity-onset diabetes of the young type 5 and congenital organ malformations. This study aimed to identify a gene defect in a patient presenting with diabetes and severe diarrhea, while also analyzing the prevalence of hypomagnesemia and its correlation with the HNF1B genotype. Whole exome sequencing was used to identify responsible point mutations and small indels in the proband and their family members. Multiplex ligation-dependent probe amplification was carried out to identify HNF1B deletions. Furthermore, an analysis of published data on 539 cumulative HNF1B cases, from 29 literature sources, was carried out to determine the correlation between the HNF1B genotype and the phenotype of serum magnesium status. Using multiplex ligation-dependent probe amplification, we identified a de novo heterozygous HNF1B deletion in the patient, who showed dorsal pancreas agenesis and multiple kidney cysts, as detected by magnetic resonance imaging. Magnesium supplementation effectively alleviated the symptoms of diarrhea. Hypomagnesemia was highly prevalent in 192 out of 354 (54.2%) patients with HNF1B syndrome. Compared with patients with intragenic mutations, those with HNF1B deletions were more likely to suffer from hypomagnesemia, with an odds ratio of 3.1 (95% confidence interval 1.8-5.4). Hypomagnesemia is highly prevalent in individuals with HNF1B syndrome, and those with HNF1B deletion are more susceptible to developing hypomagnesemia compared with those with intragenic mutations. The genotype-phenotype associations in HNF1B syndrome have significant implications for endocrinologists in terms of genotype detection, treatment decisions and prognosis assessment.

Identification and precision therapy for three maturity-onset diabetes of the young (MODY) families caused by mutations in the HNF4A gene.

Heterozygous pathogenic variants in HNF4A gene cause maturity-onset diabetes of the young type 1 (MODY1). The mutation carriers for MODY1 have been reported to be relatively rare, in contrast to the most frequently reported forms of MODY2 and MODY3. Whole exome sequencing (WES) and Sanger sequencing were performed for genetic analysis of MODY pedigrees. Tertiary structures of the mutated proteins were predicted using PyMOL software. Three heterozygous missense mutations in the HNF4A gene, I159T, W179C, and D260N, were identified in the probands of three unrelated MODY families using WES, one of which (W179C) was novel. Cascade genetic screening revealed that the mutations co-segregated with hyperglycemic phenotypes in their families. The molecular diagnosis of MODY1 has partly transformed its management in clinical practice and improved glycemic control. The proband in family A successfully converted to sulfonylureas and achieved good glycemic control. Proband B responded well to metformin combined with diet therapy because of his higher body mass index (BMI). The proband in family C, with paternal-derived mutations, had markedly defective pancreatic β-cell function due to the superposition effect of T2DM susceptibility genes from the maternal grandfather, and he is currently treated with insulin. In silico analysis using PyMOL showed that the I159T and D260N mutations altered polar interactions with the surrounding residues, and W179C resulted in a smaller side chain. We identified three heterozygous missense mutations of HNF4A from Chinese MODY families. Structural alterations in these mutations may lead to defects in protein function, further contributing to the hyperglycemic phenotype of mutation carriers.

Low-Dose Glimepiride and Metformin Fixed-Dose Combination in treating Maturity-Onset Diabetes of the Young Type (MODY): A Cross Sectional Survey

Low-Dose Glimepiride and Metformin Fixed-Dose Combination in treating Maturity-Onset Diabetes of the Young Type (MODY): A Cross Sectional Survey

Hepatic adenoma in a 7-year-old girl: a case report and literature review

BackgroundHepatocellular adenomas (HCAs) are rare benign tumors of the liver that occur predominantly in women taking oral contraceptives. In children, HCAs comprise < 5% of hepatic tumors. We report a case of HCAs in a 7-year-old girl with estrogen and glucose imbalance.Case presentationA 7-year-old girl was presented to our hospital with bilateral breast enlargement for 2 months, polydipsia, polyuria, polyphagia, hyperglycemia, and significant weight gain. Computed tomography (CT) showed a 7.2 cm×6.9 cm×5.3 cm round-shaped mass in the left inner lobe of the liver, ovarian ultrasound showed multiple follicles in the ovaries bilaterally, and cranial magnetic resonance imaging (MRI) showed an enlarged superior pituitary. Hematological and biochemical results were as follows: fasting glucose was 19.7 mmol/L, estradiol was 122.9 pmol/L, follicle-stimulating hormone 10.81 IU/L, luteinizing hormone 10.99 IU/L, insulin-like growth factor 1,513 ng/mL, glutamine aminotransferase 86 U/L, and alkaline phosphatase 362 U/L. Thyroid functions, methemoglobin, fetal protein, carcinoembryonic antigen, and chorionic gonadotropin were normal. The patient had a complete surgical resection of the liver tumor, and the postoperative histopathological diagnosis was HCAs. After the surgery, insulin was injected and the glucose levels were stable. During the 36-month follow-up period, neither tumor recurrence nor significant abnormalities were detected using color Doppler ultrasound of the liver. The child’s precocious puberty is currently under control.ConclusionsHCAs are particularly rare in children with liver tumors, and risk factors for the development of HCAs in children include sex hormone imbalance, obesity, Fanconi anemia (FA), glycogen storage diseases (GSDs) type I, III, and IV, galactosemia, immunodeficiency, congenital portosystemic shunts (CPSS), cardiac hepatopathy status-post Fontan procedure, Hurler syndrome, familial adenomatous polyposis, germline HNF1A mutations, and maturity-onset diabetes of the young type 3. Most HCAs are detected during a physical examination without clinical symptoms, and some patients may present with symptoms such as abdominal pain, abdominal distension, and abdominal masse. Serum liver function tests can show increased alkaline phosphatase (ALP) and γ- glutamyl transferase (GT), whereas α-Fetoprofein (AFP) levels are normal. The definitive diagnosis relies mainly on histopathological examination. Because HCAs can rupture and bleed and become malignant. Early surgical treatment is recommended after detection.

Hepatocellular Adenoma: Report of 2 Cases That Highlight the Relevance of Phenotype-Genotype Correlation in the Pediatric Population.

Hepatocellular adenoma (HCA) in the pediatric population is very rare and there are only limited studies, especially with molecular characterization of the tumors. Main HCA subtypes recognized in the current WHO classification include HNF1A-inactivated HCA (H-HCA), inflammatory HCA (IHCA), β-catenin-activated HCA (b-HCA), and β-catenin-activated IHCA (b-IHCA) and sonic hedgehog HCA (shHCA) is reported as an emerging subtype. Clinical history, pathological information, and molecular studies for a series of 2 cases of pediatric HCA were reviewed. Case 1 was a b-HCA characterized by somatic CTNNB1 S45 mutation in a 11-year-old male with Abernethy malformation. Case 2 was a H-HCA characterized by germline HNF1A variant (c.526+1G>A) in a 15-year-old male associated with maturity-onset diabetes of the young type 3 (MODY3). Our findings highlight the rarity of these 2 cases associated with adenomatosis, and the contribution of molecular/genetic analysis for proper sub-typing, prognosis and family surveillance.

De novo HNF1A mutation of young maturity-onset diabetes 3 of a young girl—Case report

Young maturity-onset diabetes of the young type3(MODY3) as a special type of diabetes, the probability of diagnosis is low. This article reports on a case and reviews the relevant knowledge of the disease. We report an 11-year-and-11-month-old girl whose grandmother died from diabetic complications while the rest of the families were non-diabetes. The proband was initially treated with insulin and metformin but the threatment proved inefficient. After an exome-targeted capture sequencing test, she was diagnosed with mature-onset diabetes of young type 3 (MODY3), and sulfonylureas make sense. The key to mody treatment is a correct and timely diagnosis, which contributes to helping patients overcome the problems of MODY3, especially for blood sugar control.

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 does not match the clinical manifestations of GDM. It is suspected that 1-2% of women diagnosed with GDM are in fact misdiagnosed maturity-onset diabetes of the young (MODY). MODY has often 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 review of literature reports the current knowledge of diagnosis, treatment and complications of the most common types of MODY in pregnancy.

A clinical mutation in glucokinase causing maturity-onset diabetes in the young type 2 increases enzyme activity.

Glucokinase (GCK) is the pancreatic β-cell glucose sensor, and its kinetics are key to that purpose. A slow transition step, displayed as non-hyperbolic kinetics, and a low affinity for glucose characterize GCK. Mutations in GCK associated with maturity-onset diabetes of the young type 2 (MODY2) previously describedreduce the functionality of the human pancreatic β-cell, leading to diabetic clinical phenotypes. We present a kinetic characterization of the G448D mutation identified in a MODY2 patient, which is one of the first mutations to exhibit increased functionality. This mutant displays increased activity, high affinity for both Mg2+ -ATP and glucose, hyperbolic kinetics and increased phosphorylation potential. Hyperbolic kinetics and assays in the presence of glycerol indicate that G448D lacks the slow transition step crucial for the pancreatic β-cell glucose sensor function.

17q12 Microdeletion Syndrome as a Rare Cause of Elevated Liver Enzymes: Case Report and Literature Review

17q12 deletion syndrome is a rare autosomal dominant inherited condition. It results from de novo mutation and can occur without a family history. Hepatocyte nuclear factor-1 beta (HNF1B) and LIM homeobox 1 (LXH1) genes are the most common genes to be deleted in this syndrome. It has unique clinical characteristics involving multiple systems in the body. The most common presentations are usually renal involvement and maturity-onset diabetes of the young type 5 (MODY5). Genetic study is the golden tool to diagnose patients with this syndrome. Our case presents the unique clinical features of 17q12 deletion syndrome along with a literature review.

Genetic predisposition to gestational diabetes mellitus in the Kazakh population

Background and aimsThe purpose of the study was to conduct a comparative analysis of population frequencies of alleles and genotypes of polymorphic variants of genes for impaired insulin synthesis and associated with insulin signal transduction. MethodsThis investigation uses a genomic database of 1800 conditionally healthy individuals of Kazakh ethnicity, who underwent full genome genotyping using OmniChip 2.5–8 Illumina chips of ∼2.5 million Single Nucleotide Polymorphism at deCODE Iceland Genomic Centre. ResultsThe highest frequency of carriage of minor A allele – 17.6% rs4607517 polymorphism of Glucokinase gene, unfavorable genotypes A/G – 29.5% and A/A – 3.0% in comparison with European and Asian populations, indicates a contribution of hereditary family forms of Maturity-onset diabetes of the young type 2 to gestational diabetes mellitus in Kazakh population. ConclusionsThe study of the associations of genetic markers of gestational diabetes mellitus will allow timely identification of high-risk groups before and at an early stage of pregnancy, carrying out the necessary effective preventive measures and, in the case of gestational diabetes mellitus development, optimizing the correction of carbohydrate metabolism disorders and predicting outcomes for the mother and the fetus.

ODP255 Woman With Maturity-Onset Diabetes of the Young Type 2 (MODY2) Mistakenly Diagnosed and Treated as Type 2 Diabetes Mellitus

Abstract Background MODY2 is a rare, monogenic form of diabetes, caused by mutations in the glucokinase gene (GCK), and is often misclassified as type 2 diabetes. Clinical case: A 37-year-old woman, during childhood, at the age of 9, was characterized as overweight and had a poor diet, despite being physically active. Her pediatrician diagnosed her with DM2 and started treatment with metformin. However, there was no improvement in fasting glucose levels, so the family decided to stop the medication on their own. In 2008, the patient became pregnant, presenting fasting glucose levels between 120-130 mg/dl (n&amp;lt;99 mg/dl), and continued without hypoglycemic treatment. In 2010, she resumed treatment for glycemic control having used: metformin, sulphonylurea, IDDP4, and basal insulin. Despite the various treatments tested, there was altered fasting glycemia, in the 130mg/dl range. In 2012, she increased her physical activity by training for a half marathon run. At the peak of her form, but maintaining hyperglycemia (always measuring while fasting), she started liraglutide 1.8mg. In 2019, she presented episodes of malaise during training, being indicated by her physician, to discontinue liraglutide, then starting dapagliflozin, but there was still no improvement of blood glucose levels. In August 2019, she was instructed to take the following medications: insulin degludec, liraglutide, and dapagliflozin. Current weight was 53kg, height 1,57cm and a BMI 21,5kg/. Laboratory exams were requested with the following results: A1C 6,6% (n: &amp;lt;5,7%), mean glycemia 143mg/dL (n: 70-99 mg/dL), fasting glycemia 127mg/dL (n: &amp;lt;100mg/dL), urea 24mg/dL (n: 13-43 mg/dL), creatinine 0,83mg/dL (n: 0,8-1,3 mg/dL), AST 16U/L (n: 10-34 U/L), ALT 17U/L (n 10-130 U/L), LDL 109mg/dL (n&amp;lt;100mg/dl), HDL 80mg/dL (n&amp;gt;60 mg/dL), TG 90mg/dL (n&amp;lt;150 mg/dL), total cholesterol 207mg/dL (&amp;lt;200 mg/dL). Faced with the suspicion of diabetes with different behavior than DM1 and DM2, genetic testing was requested for confirmation. In September 2019, the result arrived, pointing out a genetic change in heterozygosis in the GCK gene. This is a rare mutation that results in the depletion of the phenylalanine amino acid at position 150 of the protein glucokinase. This result confirmed the diagnose of MODY type 2. The patient was oriented to discontinue anti-hyperglycemic agents, maintain a low glycemic index diet, and daily physical exercises. Thus, she has been maintaining excellent glycemic control and adequate weight. Conclusion Suspicion and characterization of MODY through clinical history, and confirmation of diagnosis through genetic testing, is essential to avoid unnecessary or inefficient treatments, and to ensure a better quality of life for the patient. Presentation: No date and time listed

Novel Loss-of-Function Variant in HNF1a Induces β-Cell Dysfunction through Endoplasmic Reticulum Stress.

Heterozygous variants in the hepatocyte nuclear factor 1a (HNF1a) cause MODY3 (maturity-onset diabetes of the young, type 3). In this study, we found a case of novel HNF1a p.Gln125* (HNF1a-Q125ter) variant clinically. However, the molecular mechanism linking the new HNF1a variant to impaired islet β-cell function remains unclear. Firstly, a similar HNF1a-Q125ter variant in zebrafish (hnf1a+/-) was generated by CRISPR/Cas9. We further crossed hnf1a+/- with several zebrafish reporter lines to investigate pancreatic β-cell function. Next, we introduced HNF1a-Q125ter and HNF1a shRNA plasmids into the Ins-1 cell line and elucidated the molecular mechanism. hnf1a+/- zebrafish significantly decreased the β-cell number, insulin expression, and secretion. Moreover, β cells in hnf1a+/- dilated ER lumen and increased the levels of ER stress markers. Similar ER-stress phenomena were observed in an HNF1a-Q125ter-transfected Ins-1 cell. Follow-up investigations demonstrated that HNF1a-Q125ter induced ER stress through activating the PERK/eIF2a/ATF4 signaling pathway. Our study found a novel loss-of-function HNF1a-Q125ter variant which induced β-cell dysfunction by activating ER stress via the PERK/eIF2a/ATF4 signaling pathway.

Hypertriglyceridemia as a main feature associated with 17q12 deletion syndrome-related hepatocyte nuclear factor 1β-maturity-onset diabetes of the young.

SummaryHepatocyte nuclear factor 1β (HNF1B) gene is located on chromosome 17q12. It is a transcription factor implicated in the early embryonic development of multiple organs. HNF1B-associated disease is a multi-system disorder with variable clinical phenotypes. There are increasing reports suggesting that the 17q12 deletion syndrome should be suspected in patients with maturity-onset diabetes of the young type 5 (MODY5) due to the deletion of HNF1B gene. In contrast to classical 17q12 syndrome in childhood with neurological disorders and autism, patients with HNF1B-MODY deletion rarely had neuropsychological disorders or learning disabilities. The diagnosis of 17q12 deletion syndrome highlighted the phenotypic heterogeneity of HNF1B-MODY patients. In this study, we report the clinical course of a Thai woman with young-onset diabetes mellitus and hypertriglyceridemia as a predominant feature due to HNF1B deletion as part of the 17q12 deletion syndrome. Our findings and others suggest that hypertriglyceridemia should be considered a syndromic feature of HNF1B-MODY. Our case also highlights the need to use sequencing with dosage analyses to detect point mutations and copy number variations to avoid missing a whole deletion of HNF1B.Learning pointsMaturity-onset diabetes of the young type 5 (MODY5) may be caused by heterozygous point mutations or whole gene deletion of HNF1B. Recent studies revealed that complete deletion of the HNF1B gene may be part of the 17q12 deletion syndrome with multi-system involvement.The length of the deletion can contribute to the phenotypic variability in patients with HNF1B-MODY due to whole gene deletion.Using next-generation sequencing alone to diagnose MODY could miss a whole gene deletion or copy number variations. Specialized detection methods such as microarray analysis or low-pass whole genome sequencing are required to accurately diagnose HNF1B-MODY as a component of the 17q12 deletion syndrome.Molecular diagnosis is necessary to distinguish other acquired cystic kidney diseases in patients with type 2 diabetes which could phenocopy HNF1B-MODY.Hypertriglyceridemia is a possible metabolic feature in patients with HNF1B-MODY due to 17q12 deletion syndrome.