青少年的成人起病型糖尿病2型和3型混合家系一例临床分析并文献复习

目的探究葡萄糖激酶基因(GCK)及肝细胞核因子1α基因(HNF-1α)同时突变致青少年的成人起病型糖尿病(MODY)的临床和遗传学特点。方法对北京协和医院2017年9月诊断的一例MODY患者及其家系的临床特征、实验室资料进行分析;对家系成员进行MODY相关致病基因检测。结果该家系的5名成员检测到GCK基因(NM_000162)c.686C>T(p.Thr229Met)杂合突变。其中3名成员同时检测到HNF-1α基因(NM_001306179)c.1531C>G(p.Gln511Glu)杂合突变。结论MODY混合家系GCK及HNF-1α基因突变导致同一家系出现不同的MODY类型。诊断时需考虑混合家系的可能性,以准确诊断。     

Routine mutation screening of HNF-1α and GCK genes in MODY diagnosis: How effective are the techniques of DHPLC and direct sequencing used in combination?

Aims/hypothesis. Mutations in the hepatocyte nuclear factor (HNF)-1α and glucokinase (GCK) genes are the major causes of monogenic forms of Type II (non-insulin-dependent) diabetes mellitus (Maturity-Onset Diabetes of the Young subtypes, MODY). We evaluated the effectiveness of fluorescent single-strand conformation polymorphism (F-SSCP), denaturing high-performance liquid chromatography (DHPLC) and sequencing based mutation detection in the molecular diagnosis of MODY. Our goal is to identify a rapid, efficient and cost effective mutation detection method for the molecular diagnosis of MODY and other human genetic disorders. Methods. We evaluated the accuracy of DHPLC in screening for MODY 2 and 3 mutations. In addition, we compared the sensitivity, specificity, cost, handling time and analysis time of fluorescent single-strand conformation polymorphism, denaturing high-performance liquid chromatography and direct sequencing screening methods. Results. Denaturing high-performance liquid chromatography is a recently developed method for mutation detection. It is cost effective, powerful and reliable and quite suitable for 22 out of the 24 fragments required for MODY 2 and 3 testing. However, exons 1 and 7 of the HNF-1α gene are very polymorphic and so direct sequencing is faster as well as more efficient and reliable. Conclusion/interpretation. Our results suggest that combining denaturing high-performance liquid chromatography and direct sequencing is a good approach for the routine detection of HNF-1α and GCK mutations in MODY families. Denaturing high-performance liquid chromatography appears to be a powerful tool in genetic testing and the method could be applied to the molecular diagnosis of other human genetic diseases. [Diabetologia (2001) 44: 775–778] Received: 15 November 2000 and in revised form: 13 February 2001     

Hepatocyte nuclear factor (HNF)1A and HNF4A substitution occurring simultaneously in a family with maturity‐onset diabetes of the young

Introduction Maturity‐onset diabetes of the young (MODY) is a monogenic form of diabetes mellitus characterized by an early age at onset, autosomal dominant inheritance and a primary defect in the function of the B‐cells of the pancreas. We report a family with two members carrying a substitution in both the hepatocyte nuclear factor (HNF)1A and HNF4A gene simultaneously. Case report A 39‐year‐old man was referred because of mild diabetic retinopathy. Because of a dominant presentation of diabetes in his family, genetic testing was performed. Sequence analysis of the genes involved in MODY‐1–3 revealed the presence of an amino acid substitution in the HNF1A as well as the HNF4A gene. Both substitutions were also detected in his mother. The HNF1A substitution has been described previously as pathogenic, whereas the HNF4A substitution had not been found previously. The HNF4A substitution was located in a conserved region of the protein and, additionally, the proband and his mother had high birthweights and low triglyceride levels, both of which are associated with pathogenic HNF4A substitutions. Conclusions To our knowledge this is the first reported family carrying both a substitution of HNF1A and HNF4A gene simultaneously. The exact contribution of each substitution to the phenotype of our subjects remains to be further elucidated, however, given the high birthweights and the low triglyceride levels in those with both substitutions, it is reasonable that the HNF4A substitution is pathogenic.     

人HNF4α基因真核表达载体的构建与鉴定*

目的体外构建人肝细胞核因子4α（HNF4α）基因真核表达载体,并初步鉴定其在HepG2细胞的表达。方法从肝癌手术患者获得肝组织,分离得到肝组织总RNA,将其逆转录合成cDNA,经特异性引物扩增HNF4α基因片段,将其定向连接到pcDNA3.1(+）真核表达载体,经抗生素筛选后,酶切及测序鉴定其序列正确。提取质粒,转染HepG2细胞,48 h后裂解细胞,应用抗HNF4α行Western blot检测目的蛋白。结果从临床肝癌患者肝组织中成功分离得到总RNA,扩增出HNF4α基因,经筛选、酶切鉴定和测序,确认pcDNA3.1-4α真核表达载体构建成功。在转染HepG2细胞48 h后,检测显示53 kDa位置有明显融合蛋白条带。结论我们成功构建了HNF4α基因真核表达载体,体外转染HepG2细胞成功表达HNF4α蛋白,为后续研究奠定了基础。     

Interferon-�� induced severe thrombocytopenia: A case report and review of the literature

We report a case of severe thrombocytopenia following pegylated interferon-α 2a (Peg-IFN-α 2a) treatment of hepatitis C virus infection and summarize the clinical characteristics of 16 cases of IFN-α induced severe thrombocytopenia and its immune-mediated mechanism. Discontinuation of IFN-α and early administration of immunosuppressants are the effective therapy for IFN-α induced severe thrombocytopenia.     

Nonsense variant of ATP8B1 gene in heterozygosis and benign recurrent intrahepatic cholestasis: A case report and review of literature

BACKGROUND Benign recurrent intrahepatic cholestasis is a genetic disorder with recurrent cholestatic jaundice due to ATP8B1 and ABCB11 gene mutations encoding for hepato-canalicular transporters. Herein, we firstly provide the evidence that a nonsense variant of ATP8B1 gene(c.1558AT) in heterozygous form is involved in BRIC pathogenesis.CASE SUMMARY A 29-year-old male showed severe jaundice and laboratory tests consistent with intrahepatic cholestasis despite normal gamma-glutamyltranspeptidase. Acute and chronic liver diseases with viral, metabolic and autoimmune etiology were excluded. Normal intra/extra-hepatic bile ducts were demonstrated by magnetic resonance. Liver biopsy showed: Cholestasis in the centrilobular and intermediate zones with bile plugs and intra-hepatocyte pigment, Kupffer's cell activation/hyperplasia and preserved biliary ducts. Being satisfied benign recurrent intrahepatic cholestasis diagnostic criteria, ATP8B1 and ABCB11 gene analysis was performed. Surprisingly, we found a novel nonsense variant of ATP8B1 gene(c.1558AT) in heterozygosis. The variant was confirmed by Sanger sequencing following a standard protocol and tested for familial segregation,showing a maternal inheritance. Immunohistochemistry confirmed a significant reduction of mutated gene related protein(familial intrahepatic cholestasis 1).The patient was treated with ursodeoxycholic acid 15 mg/kg per day and colestyramine 8 g daily with total bilirubin decrease and normalization at the 6~(th) and 12~(th) mo.CONCLUSION A genetic abnormality, different from those already known, could be involved in familial intrahepatic cholestatic disorders and/or pro-cholestatic genetic predisposition, thus encouraging further mutation detection in this field.     

Clinical application of next-generation sequencing for the management of desmoid tumors: A case report and literature review

Rationale:Desmoid tumors are rare myofibroblastic neoplasms characterized by local invasiveness and high rates of recurrence, and sometimes mimic local recurrence of previously resected malignancies. Previous studies have suggested that molecular profiling may be useful for the diagnosis of the tumors and risk stratification. However, the clinical utility of next-generation sequencing (NGS) for the management of desmoid tumors has not been established.Patient concerns:A 42-year-old man visited our clinic for routine follow-up 1 year after left upper lobe lingular segmentectomy for lung adenocarcinoma.Diagnoses:Chest computed tomography showed a pleural mass adherent to the thoracotomy site. Positron emission tomography revealed mildly increased metabolism with a maximal standardized uptake value of 2.7 within the tumor, suggesting local recurrence of the previous neoplasm. Exploratory thoracotomy and en bloc resection of the tumor revealed spindle cells in a massive collagenous tissue consistent with a desmoid tumor.Interventions:NGS was performed to confirm the diagnosis and to identify any genetic alterations that might be relevant to the prognosis of this tumor. The tumor harbored an S45F mutation in CTNNB1, which has been correlated with a high recurrence rate. Therefore, we performed adjuvant radiotherapy on the resection bed at a dose of 56 Gy.Outcomes:The patients experienced no postoperative or radiotherapy-related complications. Periodic follow-up examinations using computed tomography were performed every 3 months, and no evidence of recurrence of either tumor was observed during the 38 months after the last surgery.Lessons:To the best of our knowledge, this is the first case reporting the clinical application of NGS and aggressive treatment based on the genotyping results for the management of a desmoid tumor. Our case highlights the need to consider desmoid tumors among the differential diagnoses when a pleural mass is encountered at a previous thoracotomy site. More importantly, molecular profiling using NGS can be useful for the establishment of a treatment strategy for this tumor, although further investigations are required.     

Molecular genetics of diabetes mellitus in Chinese subjects: identification of mutations in glucokinase and hepatocyte nuclear factor-1alpha genes in patients with early-onset type 2 diabetes mellitus/MODY.

AIMS: To examine the prevalence of identified MODY-related genes in Chinese subjects with early onset Type 2 diabetes mellitus and a positive family history of diabetes and to look for possible associations between the gene mutations and the development of diabetes. METHODS: Ninety-two unrelated Chinese subjects with diabetes diagnosed before the age of 40 years who had a positive family history of diabetes were screened for mutations in hepatocyte nuclear factors (HNF-1alpha and HNF-4alpha) and glucokinase genes by direct sequencing. The family members of patients with mutations and 100 healthy controls were also examined. RESULTS: Mutations in the HNF-1alpha and the glucokinase genes were found in 5% and 3% of the diabetic subjects, respectively but no mutations were found in the coding region of the HNF-4alpha gene. Three mutations found in the glucokinase gene were novel missense mutations (I110T, A119D and G385V). The mutations in the HNF-1alpha gene were also new and included four missense mutations (G20R, R203H, S432C, I618M) and one splice acceptor site mutation (IVS2nt-1G-->A). Patients with mutations in these genes were clinically heterogeneous with respect to phenotype and basal pancreatic beta cell function. CONCLUSIONS: Genetic factors such as mutations in the HNF-1alpha and glucokinase genes may be important in the development of diabetes in Chinese people, especially when the disease is of early onset.     

In silico and in vitro analyses of the pathological relevance of the R258H mutation of hepatocyte nuclear factor 4α identified in maturity‐onset diabetes of the young type 1

Mutations of the hepatocyte nuclear factor 4α (HNF4α) gene give rise to maturity‐onset diabetes of the young type 1. Although many such mutations have been identified in affected individuals, part of these mutations has been characterized with regard to their pathological relevance. We here identified a missense mutation (c.773G>A, p.R258H) of HNF4A in a mother and daughter with early‐onset diabetes and impaired insulin secretion. In silico simulation and in vitro luciferase reporter analyses showed that the mutation impairs the stability of self‐dimerization and the transactivation activity of HNF4α. Although arginine‐258 does not appear to participate directly in dimerization, its mutation alters the electrostatic surface potential of the dimer interface. Our results thus suggest that this mutation impairs the function of HNF4α and thereby contributes to the pathogenesis of maturity‐onset diabetes of the young type 1.     

Successful treatment of arrhythmia with β‐blocker and flecainide combination in pregnant patients with Andersen–Tawil syndrome: A case report and literature review

Andersen–Tawil syndrome (ATS) is a rare disorder characterized by a triad of ventricular arrhythmia (VA), dysmorphic features, and periodic paralysis. Due to the rarity of this condition, less is known about physiologic effect of pregnancy to ATS and arrhythmia. There is no established guideline for peripartum or postpartum treatment and prevention of arrhythmia in ATS; thus, the clinical management is challenging. We reported two KCNJ2‐associated ATS patients who got pregnant and underwent vaginal birth safely. Both individuals had VA, micrognathia without periodic paralysis. β‐blocker plus flecainide could be an effective treatment combination when monotherapy failed to control arrhythmia. VA of two pregnant patients with ATS could be controlled by either physiologic changes associated pregnancy or the combination treatment of β‐blocker and flecainide.     

Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature

Steroid 5β-reductase [aldo-keto reductase family 1 member D1(AKR1D1)] is essential for bile acid biosynthesis. Bile acid deficiency caused by genetic defects in AKR1D1 leads to life-threatening neonatal hepatitis and cholestasis. There is still limited experience regarding the treatment of this disease. We describe an infant who presented with hyperbilirubinemia and coagulopathy but normal bile acid and γ-glutamyltransferase. Gene analysis was performed using genomic DNA from peripheral lymphocytes from the patient, his parents, and his elder brother. The patient was compound heterozygous for c.919CT in exon 8 and exhibited a loss of heterozygosity of the AKR1D1 gene, which led to an amino acid substitution of arginine by cysteine at amino acid position 307(p.R307C). Based on these mutations, the patient was confirmed to have primary 5β-reductase deficiency. Ursodeoxycholic acid(UDCA) treatment did not have any effect on the patient. However, when we changed to chenodeoxycholic acid(CDCA) treatment, his symptoms and laboratory tests gradually improved. It is therefore crucial to supplement with an adequate dose of CDCA early to improve clinical symptoms and to normalize laboratory tests.     

Mutations in AR or SRD5A2 Genes: Clinical Findings,Endocrine Pitfalls,and Genetic Features of Children with 46,XY DSD

Objective:Androgen insensivity syndrome (AIS) and 5α-reductase deficiency (5α-RD) present with indistinguishable phenotypes among the 46,XY disorders of sexual development (DSD) that usually necessitate molecular analyses for the definitive diagnosis in the prepubertal period. The aim was to evaluate the clinical, hormonal and genetic findings of 46,XY DSD patients who were diagnosed as AIS or 5α-RD.Methods:Patients diagnosed as AIS or 5α-RD according to clinical and hormonal evaluations were investigated. Sequence variants of steroid 5-α-reductase type 2 were analyzed in cases with testosterone/dihydrotestosterone (T/DHT) ratio of ≥20, whereas the androgen receptor (AR) gene was screened when the ratio was <20. Stepwise analysis of other associated genes were screened in cases with no causative variant found in initial analysis. For statistical comparisons, the group was divided into three main groups and subgroups according to their genetic diagnosis and T/DHT ratios.Results:A total of 128 DSD patients from 125 non-related families were enrolled. Birth weight SDS and gestational weeks were significantly higher in 5α-RD group than in AIS and undiagnosed groups. Completely female phenotype was higher in all subgroups of both AIS and 5α-RD patients than in the undiagnosed subgroups. In those patients with stimulated T/DHT <20 in the prepubertal period, stimulated T/DHT ratio was significantly lower in AIS than in the undiagnosed group, and higher in 5α-RD. Phenotype associated variants were detected in 24% (n=18 AIS, n=14 5α-RD) of the patients, revealing four novel AR variants (c.94G>T, p.Glu32*, c.330G>C, p.Leu110=; c.2084C>T, p.Pro695Leu, c.2585_2592delAGCTCCTG, p.(Lys862Argfs*16), of these c.330G>C with silent status remained undefined in terms of its causative effects.Conclusion:T/DHT ratio is an important hormonal criterion, but in some cases, T/DHT ratio may lead to diagnostic confusion. Molecular diagnosis is important for the robust diagnosis of 46,XY DSD patients. Four novel AR variants were identified in our study.     

Gly482Ser polymorphism of the peroxisome proliferator-activated receptor-gamma coactivator-1 gene might be a risk factor for diabetic retinopathy in Slovene population (Caucasians) with type 2 diabetes and the Pro12Ala polymorphism of the PPARgamma gene is not

BACKGROUND: The peroxisome proliferator-activated receptor-gamma (PPARgamma) gene has been recently associated with type 2 diabetes, obesity and traits depending on VEGF expression (e.g. retinopathy). The PPARgamma gene and its coactivator, the peroxisome proliferator-activated receptor-gamma coactivator-1 (PPARGC1) gene, have been implicated to be involved in glucose uptake and altered lipid oxidation. We therefore hypothesized that the Gly482Ser polymorphism of the PPARGC1 gene and Pro12Ala polymorphism of the PPARgamma gene might confer susceptibility to diabetic retinopathy in type 2 diabetes. The aim of this study was to investigate the association between the Pro12Ala polymorphism in the PPARgamma gene and Gly482Ser polymorphism in the PPARGC1 gene and the development of diabetic retinopathy in the Slovene population (Caucasians) with type 2 diabetes. METHODS: One hundred and sixty subjects with type 2 diabetes and diabetic retinopathy were compared with 101 diabetic subjects without diabetic retinopathy. Chi-square test was used to compare discrete variables, and continuous clinical data were compared by unpaired students t - test. RESULTS: A significantly higher frequency of the AA genotype of the Gly482Ser polymorphism of the PPARGC1 gene was found in the patients with diabetic retinopathy compared to the patients without diabetic retinopathy (14.4% vs 5.9%; p = 0.035), whereas the Pro12Ala polymorphism of the PPARgamma gene failed to yield an association with diabetic retinopathy. CONCLUSIONS: The present study demonstrates that the AA genotype of the Gly482Ser polymorphism in the PPARGC1 gene might be a risk factor for diabetic retinopathy in the Slovene population (Caucasians) with type 2 diabetes (odds ratio 2.7, 95% confidence interval 1.0-6.8), whereas the Pro12Ala polymorphism of the PPARgamma gene failed to confer susceptibility to diabetic retinopathy.     

An examination of sex and racial/ethnic differences in the metabolic syndrome among adults: A confirmatory factor analysis and a resulting continuous severity score

Objective

The metabolic syndrome (MetS) is typically diagnosed based on abnormalities in specific clustered clinical measures that are associated with increased risk for coronary heart disease (CHD) and Type 2 diabetes mellitus (T2DM). However, current MetS criteria result in racial/ethnic discrepancies. Our goals were to use confirmatory factor analysis (CFA) to delineate differential contributions to MetS by sub-group, and if contributions were discovered, develop sex and racial/ethnic-specific equations to calculate MetS severity.

Research Design and Methods

Using data on adults from the National Health and Nutrition Examination Survey 1999–2010, we performed a CFA of a single MetS factor that allowed differential loadings across groups, resulting in a sex and race/ethnicity-specific continuous MetS severity score.

Results

Loadings to the single MetS factor differed by sub-group for each MetS component (p < 0.001), with lower factor loadings among non-Hispanic-blacks for triglycerides and among Hispanics for waist circumference. Systolic blood pressure exhibited low factor loadings among all groups. MetS severity scores were correlated with biomarkers of future disease (high-sensitivity C-reactive-protein, uric acid, insulin resistance). Non-Hispanic-black-males with diabetics had a low prevalence of MetS but high MetS severity scores that were not significantly different from other racial/ethnic groups.

Conclusions

This analysis among adults uniquely demonstrated differences between sexes and racial/ethnic groups regarding contributions of traditional MetS components to an assumed single factor. The resulting equations provide a clinically-accessible and interpretable continuous measure of MetS for potential use in identifying adults at higher risk for MetS-related diseases and following changes within individuals over time. These equations hold potential to be a powerful new outcome for use in MetS-focused research and interventions.