Screening of HNF1A and HNF4A mutation and clinical phenotype analysis in a large cohort of Chinese patients with maturity-onset diabetes of the young

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

Background

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.

Methods

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.

Results

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.

Discussion

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.

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.

Clinical Characteristics and Gene Mutations of Two Families with MODY 3 in Inner Mongolia

Objective

This study aimed to analyze the clinical characteristics and gene mutations of two families with maturity-onset diabetes of the young 3 (MODY 3) in Inner Mongolia.

Methods

Fifty-three patients in Inner Mongolia suspected of having MODY 3 were enrolled in this study according to clinical manifestations. Blood samples were collected, and all exons of the HNF1α gene were analyzed; the second-generation DNA of the splicing regions of the gene was determined by direct sequencing.

Results

In Family 1, the proband, mother, and uncle all carried the missense heterozygous mutation on exon 2 of the HNF1α gene (c.512G>A, p.Arg171Gln), and both the proband and uncle had MODY 3. In Family 2, the proband, grandfather, father, uncle I, and uncle II all carried a missense mutation on exon 2 (c.391C>t, p.Arg131Trp), and all had MODY 3. The blood glucose control in these patients was stable while they were being treated with oral sulfonylurea hypoglycemic drugs alone or with insulin. Uncle II had serious macrovascular and microvascular complications.

Conclusion

Maturity-onset diabetes of the young 3 gene mutations (c.512G>A, p.Arg171Gln) and (c.391C>T, p.Arg131Trp) may be the main pathogenic genes of the two families with MODY 3. The two gene mutations found in this study have not been reported previously in China.

A new screening strategy and whole-exome sequencing for the early diagnosis of maturity-onset diabetes of the young

AIMS

This study aimed to establish a systematic screening strategy to select candidates for genetic testing among patients with maturity-onset diabetes of the young (MODY) and to accomplish early diagnosis of MODY.

MATERIALS AND METHODS

We enrolled 1478 sporadic patients from the outpatient department of endocrinology. Out of the1478 patients, 1279 participants were successfully screened according to the "AACM" strategy, which includes the age of onset, autoantibody to islet antigen, C-peptide and metabolic syndrome. Another six probands and their families who fulfilled the common clinical criteria for MODY were also examined for causative gene mutations. Whole-exome sequencing (WES) was performed to examine the mutations.

RESULTS

A total of 24 out of 1279 sporadic patients with newly diagnosed diabetes were eligible for genetic testing. Mutations were found in 4/24 participants in the cohort, as well as in 2/6 pedigrees. A likely pathogenic alteration, a likely benign alteration and three alterations with uncertain significance were identified with WES. Most of the mutant genes recognised in our trial were not the most common causative genes of MODY, and all of the mutations were specifically reported in Asian patients only, suggesting a unique genetic background of MODY in different ethnicities.

CONCLUSIONS

In this systematic study of MODY in a new-onset diabetes cohort, MODY cases were incorrectly diagnosed as type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), suggesting that an observant clinician is necessary for early and correct MODY diagnosis. This systematic approach to screening is practical and specific enough to identify patients who are most appropriate for genetic testing.

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.

Precision Therapy for a Chinese Family With Maturity-Onset Diabetes of the Young

OBJECTIVE

To determine the pathogenic gene and explore the clinical characteristics of maturity-onset diabetes of the young type 2 (MODY2) pedigree caused by a mutation in the glucokinase (GCK) gene.

METHODS

Using whole-exome sequencing (WES), the pathogenic gene was detected in the proband-a 20-year-old young man who was accidentally found with hyperglycemia, no ketosis tendency, and a family history of diabetes. The family members of the proband were examined. In addition, relevant clinical data were obtained and genomic DNA from peripheral blood was obtained. Pathologic variants of the candidate were verified by Sanger sequencing technology, and cosegregation tests were conducted among other family members and non-related healthy controls. After adjusting the treatment plan based on the results of genetic testing, changes in biochemical parameters, such as blood glucose levels and HAblc levels were determined.

RESULTS

In the GCK gene (NM_000162) in exon 9, a heterozygous missense mutation c.1160C > T (p.Ala387Val) was found in the proband, his father, uncle, and grandmother. Thus mutation, which was found to co-segregate with diabetes, was the first discovery of such a mutation in the Asian population. After stopping hypoglycemic drug treatment, good glycemic control was achieved with diet and exercise therapy.

CONCLUSION

GCK gene mutation c.1160C > T (p.Ala387Val) is the pathogenic gene in the GCK-MODY pedigree. Formulating an optimized and personalized treatment strategy can reduce unnecessary excessive medical treatment and adverse drug reactions, and maintain a good HbA1c compliance rate.

Clinical and Genetic Characterization of 153 Patients with Persistent or Transient Congenital Hyperinsulinism

CONTEXT

Major advances have been made in the genetics and classification of congenital hyperinsulinism (CHI).

OBJECTIVE

To examine the genetics and clinical characteristics of patients with persistent and transient CHI.

DESIGN

A cross-sectional study with the register data and targeted sequencing of 104 genes affecting glucose metabolism.

PATIENTS

Genetic and phenotypic data were collected from 153 patients with persistent (n = 95) and transient (n = 58) CHI diagnosed between 1972 and 2015. Of these, 86 patients with persistent and 58 with transient CHI participated in the analysis of the selected 104 genes affecting glucose metabolism, including 10 CHI-associated genes, and 9 patients with persistent CHI were included because of their previously confirmed genetic diagnosis.

MAIN OUTCOME MEASURES

Targeted next-generation sequencing results and genotype-phenotype associations.

RESULTS

Five novel and 21 previously reported pathogenic or likely pathogenic variants in ABCC8, KCNJ11, GLUD1, GCK, HNF4A, and SLC16A1 genes were found in 68% (n = 65) and 0% of the patients with persistent and transient CHI, respectively. KATP channel mutations explained 82% of the mutation positive cases.

CONCLUSIONS

The genetic variants found in this nationwide CHI cohort are in agreement with previous studies, mutations in the KATP channel genes being the major causes of the disease. Pathogenic CHI-associated variants were not identified in patients who were both diazoxide responsive and able to discontinue medication within the first 4 months. Therefore, our results support the notion that genetic testing should be focused on patients with inadequate response or prolonged need for medication.

Primary hepatocellular adenoma due to biallelic HNF1A mutations and its co-occurrence with MODY 3: case-report and review of the literature

PURPOSE

Maturity-onset diabetes of the young type 3 (MODY 3) is a consequence of heterozygous germline mutations in HNF1A, and a subtype of hepatocellular adenoma (HCA) is caused by biallelic somatic HNF1A mutations; rare HCA may be related to MODY 3. This study aimed to investigate the cosegregation of HNF1A mutations with diabetes and HCA in two families.

METHODS

Two patients suffering from HCA and diabetes were screened for HNF1A germline and somatic mutations using direct sequence analysis and methylation-specific multiplex-ligation-dependent probe amplification (MS-MLPA) assay. Further, we screened eight relatives in the two independent families for diabetes, HCA and HNF1A variants. Additionally, we reviewed the literature concerning the phenotypes of MODY 3 and HCA at the background of HNF1A mutations.

RESULTS

Here we reported two families (a total of six relatives) with two missense germline mutations of HNF1A identified initially using direct sequence analysis (c.686G>A in family A and c.526 + 1G>A in family B). Somatic deletion of the second allele of HNF1A was found in liver tumor tissues in both probands who were diagnosed with HCA. There are a total of ten cases of both MODY 3 and HCA phenotypes reported in the literature to date; incomplete penetrance for HCA was observed, and all the patients with HCA developed diabetes. The onset of diabetes and HCA was highly variable, the treatment of diabetes varied from diet to insulin, and the clinical expression of HCA ranged from silent to hemorrhage. Further, the severity of diabetes mellitus was not related to the occurrence of HCA.

CONCLUSIONS

This study describes the association of HCA and MODY 3 at the background of HNF1A mutations and highlights the importance of screening for HCA in MODY 3 families to avoid the possibility of severe complications. Further, the current study indicated that there may be a special mutational spectrum of HNF1A correlated with HCA in MODY 3 families.

Using Clinical Indices to Distinguish MODY2 (GCK Mutation) and MODY3 (HNF1A Mutation) from Type 1 Diabetes in a Young Chinese Population

INTRODUCTION

Accurate diagnosis of maturity-onset diabetes of the young (MODY) is required in order to select appropriate treatment options and to assess prognosis. The aim of this study was to explore potential clinical indicators that could be used to differentiate MODY2, MODY3, and type 1 diabetes (T1D) in young subjects.

METHODS

Twelve patients with MODY3 and 29 patients with MODY2 were characterized and compared to 26 patients with T1D. These three groups were matched for age and gender. Clinical profiles of the 67 patients were collected. Receiver operating characteristic (ROC) curves were used to identify the optimal cutoff values of clinical indicators.

RESULTS

Compared to patients with T1D, subjects with MODY3 had higher fasting C-peptide levels (1.34 ± 1.51 vs. 0.29 ± 0.22 ng/mL; P  < 0.001) and lower high-sensitivity C-reactive protein (hsCRP) levels (0.18 ± 0.15 vs. 1.22 ± 1.49 mg/L, P  = 0.004); patients with MODY2 had lower hsCRP (0.37 ± 0.39 vs. 1.22 ± 1.49 mg/L; P  = 0.003), total cholesterol (4.12 ± 0.68 vs. 4.61 ± 0.81 mmol/L, P  = 0.034), and low-density lipoprotein cholesterol (LDL-C) (2.24 ± 0.68 vs. 2.67 ± 0.79 ng/L, P  = 0.002) levels and higher fasting C-peptide levels (0.96 ± 0.42 vs. 0.29 ± 0.22 ng/mL, P  = 0.002). The ROC-derived hsCRP values for discriminating MODY2 from T1D, MODY3 from T1D, and MODY3 from MODY2 were 0.675, 0.833, and 0.763, respectively. The ROC-derived fasting C-peptide levels for discriminating MODY2 from T1D and MODY3 from T1D were 0.951 and 0.975, respectively. The ROC-derived total cholesterol and LDL-C values for discriminating MODY2 from T1D were 0.670 and 0.662, respectively; the ROC-derived triglyceride value for discriminating MODY3 from MODY2 was 0.756. Additionally, a combination of indicators permitted better discrimination of MODY subtypes than any single parameter.

CONCLUSION

Our findings suggest that fasting C-peptide, hsCRP, and lipid levels permit good discrimination among MODY2, MODY3, and T1D. These clinical indicators could be used as markers of MODY2 and MODY3 in young patients with diabetes.

Birthweight correlates with later metabolic abnormalities in Chinese patients with maturity-onset diabetes of the young type 2

PURPOSE

Glucokinase-maturity onset diabetes of the young (GCK-MODY), also known as MODY2, is caused by heterozygous inactivating mutations in the GCK gene. The aim of this study is to investigate the relationship of birthweight and cardiometabolic characteristics in MODY2 patients.

METHODS

Genetic screening for GCK mutations from 192 classical MODY families was performed, and birthweight and clinical profiles of 76 patients from 25 families with identified GCK mutations were collected.

RESULTS

Mutations in GCK were identified in 25 (13%) of the 192 families. Four novel (c.1334 G > C, c.1289_1294delTGACGC, c.584 T > C, and c.30delC) and twenty-one previously reported mutations were identified and cosegregated with the clinical phenotypes of MODY2 within the pedigrees. MODY2 patients presented a mean birthweight of 3.11 ± 0.44 kg. Additionally, birthweight was negatively correlated with 2 h-postprandial glucose (r = -0.426, P = 0.006), glycated albumin (r = -0.462, P = 0.035), glycated hemoglobin (r = -0.529, P = 0.001), total cholesterol (r = -0.430, P = 0.016), and low-density lipoprotein cholesterol (LDL-C) (r = -0.383, P = 0.033) levels after adjustment for age, gender and BMI. Importantly, among the patients who inherited mutations from their mothers, 7 patients whose mothers were treated with insulin during pregnancy had particularly lower birthweight (2.83 ± 0.39 vs. 3.37 ± 0.39 kg; P = 0.003), higher total cholesterol (6.15 ± 0.43 vs. 4.06 ± 0.16 mmol/L; P = 0.002) and LDL-C (4.05 ± 0.35 vs. 2.21 ± 0.13 mmol/L; P = 0.001) levels compared to the other 21 patients whose mothers received no treatment.

CONCLUSIONS

The correlations between birthweight and cardiometabolic indexes indicated that MODY2 patients with lower birthweight (<3.1 kg) should be monitored and treated more actively to prevent metabolic abnormalities, particularly dyslipidemia. Importantly, prenatal genic diagnosis is highly recommended to avoid inappropriate treatment in pregnancy leading to lower birthweight of offspring.