Maturity-onset diabetes of the young type 9 or latent autoimmune diabetes in adults:A case report and review of literature

BACKGROUND Maturity-onset diabetes of the young(MODY)is a monogenic genetic disease often clinically misdiagnosed as type 1 or type 2 diabetes.MODY type 9(MODY9)is a rare subtype caused by mutations in the PAX4 gene.Currently,there are limited reports on PAX4-MODY,and its clinical characteristics and treatments are still unclear.In this report,we described a Chinese patient with high autoimmune antibodies,hyperglycemia and a site mutation in the PAX4 gene.CASE SUMMARY A 42-year-old obese woman suffered diabetes ketoacidosis after consuming substantial amounts of beverages.She had never had diabetes before,and no one in her family had it.However,her autoantibody tested positive,and she managed her blood glucose within the normal range for 6 mo through lifestyle interventions.Later,her blood glucose gradually increased.Next-generation sequencing and Sanger sequencing were performed on her family.The results revealed that she and her mother had a heterozygous mutation in the PAX4 gene(c.314G>A,p.R105H),but her daughter did not.The patient is currently taking liraglutide(1.8 mg/d),and her blood glucose levels are under control.Previous cases were retrieved from PubMed to investigate the relationship between PAX4 gene mutations and diabetes.CONCLUSION We reported the first case of a PAX4 gene heterozygous mutation site(c.314G>A,p.R105H),which does not appear pathogenic to MODY9 but may facilitate the progression of latent autoimmune diabetes in adults.

Latent autoimmune diabetes in adults： evidences for diabetes spectrum？

In 1936, Himworth first investigated insulin resistance and non-insulin resistance in diabetes. Then the terminology ＂type 1 diabetes （T1D）＂ and ＂type 2 diabetes （T2D）＂ were first used in 1951. In 1999, the World Health Organization （WHO） announced the classification of diabetes： as we all known, T1D and T2D.1 This classification is widely accepted and used. However, in clinical practice, it is quite often to find some patients cannot be simply diagnosed as T1D or T2D.

Six-year follow-up of pancreatic β cell function in adults with latent autoimmune diabetes

AIM: To investigate the characteristics of the progression of islet β cell function in Chinese latent autoimmune diabetes in adult (LADA) patients with glutamic acid decarboxylase antibody (GAD-Ab) positivity, and to explore the prognostic factors for β cell function. METHODS: Forty-five LADA patients with GAD-Ab positivity screened from phenotypic type 2 diabetic (T2DM) patients and 45 T2DM patients without GAD-Ab matched as controls were followed-up every 6 mo. Sixteen patients in LADA1 and T2DM1 groups respectively have been followed-up for 6 years, while 29 patients in LADA2 and T2DM2 groups respectively for only 1.5 years. GAD-Ab was determined by radioligand assay, and C-peptides (CP) by radioimmune assay.RESULTS: The percentage of patients whose fasting CP(FCP) decreased more than 50% compared with thebaseline reached to 25.0% at 1.5th year in LADA1 group, and FCP level decreased (395.8±71.5 vs 572.8±72.3 pmol/L, P＜0.05) at 2.5th year and continuously went down to the end of follow-up. No significant changes of the above parameters were found in T2DM1 group. The average decreased percentages of FCP per year in LADA and T2DM patients were 15.8% (4.0-91.0%) and 5.2% (-3.5 to 35.5%, P= 0.000) respectively. The index of GAD-Ab was negatively correlated with the FCP in LADA patients (rs= -0.483, P = 0.000). The decreased percentage of FCP per year in LADA patients were correlated with GAD-Ab index, body mass index (BMI) and age at onset (rs = 0.408, -0.301 and -0.523 respectively, P＜0.05). Moreover, GAD-Ab wasthe only risk factor for predicting βcell failure in LADA patients (B = 1.455, EXP (B) = 4.283, P = 0.023). CONCLUSION: The decreasing rate of islet β cell function in LADA, being highly heterogeneous, is three times that of T2DM patients. The titer of GAD-Ab is an important predictor for the progression of islet β cell function, and age at onset and BMI could also act as the predictors.

Newly diagnosed diabetes mellitus patients presenting with proliferative diabetic retinopathy as an initial sign

AIM: To investigate the clinical features of newly diagnosed diabetes mellitus(NDM) patients showing proliferative diabetic retinopathy(PDR) as an initial sign. ·METHODS: As a retrospective case series,the medical records of a total of four hundred and thirty-two patients who underwent a vitrectomy due to PDR were reviewed to find the subjects. Of 432 patients,six cases of NDM patients showing PDR as an initial sign were included and analyzed with their systemic and ocular features. Main outcome measures: the systemic features and ocular features [preoperative and postoperative best corrected visual acuity(BCVA),intraoperative findings]. ·RESULTS: The mean onset age of visual symptoms was 36.3 years old. The mean serum insulin and C-peptide titer was below the normal range. The mean fasting plasma glucose was 178mg/dL and the mean postprandial 2h plasma glucose was 306mg/dL. The mean HbA1c at diagnosis was 11.02%. In all cases,an acute progressive fibrovascular proliferation was observed. Intraoperative retinal tears were found in three cases of six. The mean preoperative BCVA was +0.67 ± 0.58 logMAR and the mean BCVA at postoperative 6 months was +0.20±0.30 logMAR. ·CONCLUSION: All patients were considered to have latent autoimmune diabetes in adults(LADA). A rapid deterioration of kidney function as well as poor diabetic control status at diagnosis was observed in all six cases. The ocular features of the patients showed acute progressive fibrovascular proliferation and relatively favorable postoperative visual acuity.