Type 1 diabetes (T1D) is an autoimmune disease characterized by the T-cell-mediated destruction of insulin-producing β-cells in pancreatic islets. It generally occurs in genetically susceptible individuals, and genetics plays a major role in the development of islet autoimmunity. Furthermore, these processes are heterogeneous among individuals; hence, different endotypes have been proposed. In this review, we highlight the interplay between genetic predisposition and other non-genetic factors, such as viral infections, diet, and gut biome, which all potentially contribute to the aetiology of T1D. We also discuss a possible active role for β-cells in initiating the pathological processes. Another component in T1D predisposition is epigenetic influences, which represent a link between genetic susceptibility and environmental factors and may account for some of the disease heterogeneity. Accordingly, a shift towards personalized therapies may improve the treatment results and, therefore, result in better outcomes for individuals in the long-run. There is also a clear need for a better understanding of the preclinical phases of T1D and finding new predictive biomarkers for earlier diagnosis and therapy, with the final goal of reverting or even preventing the development of the disease.

Type 1 diabetes is a chronic autoimmune disease in which the destruction of pancreatic β cells leads to hyperglycemia. The prevention of hyperglycemia is very important to avoid or at least postpone the development of micro- and macrovascular complications, also known as late complications. These include diabetic retinopathy, chronic renal failure, diabetic neuropathy, and cardiovascular diseases. The impact of long-term hyperglycemia has been shown to persist long after the normalization of blood glucose levels, a phenomenon known as metabolic memory. It is believed that epigenetic mechanisms such as DNA methylation, histone modifications, and microRNAs, play an important role in metabolic memory. The aim of this review is to address the impact of long-term hyperglycemia on epigenetic marks in late complications of type 1 diabetes.

Type 1 diabetes (T1D) is one of the most common chronic diseases of the endocrine system, associated with several life-threatening comorbidities. While the etiopathogenesis of T1D remains elusive, a combination of genetic susceptibility and environmental factors, such as microbial infections, are thought to be involved in the development of the disease. The prime model for studying the genetic component of T1D predisposition encompasses polymorphisms within the HLA (human leukocyte antigen) region responsible for the specificity of antigen presentation to lymphocytes. Apart from polymorphisms, genomic reorganization caused by repeat elements and endogenous viral elements (EVEs) might be involved in T1D predisposition. Such elements are human endogenous retroviruses (HERVs) and non-long terminal repeat (non-LTR) retrotransposons, including long and short interspersed nuclear elements (LINEs and SINEs). In line with their parasitic origin and selfish behaviour, retrotransposon-imposed gene regulation is a major source of genetic variation and instability in the human genome, and may represent the missing link between genetic susceptibility and environmental factors long thought to contribute to T1D onset. Autoreactive immune cell subtypes with differentially expressed retrotransposons can be identified with single-cell transcriptomics, and personalized assembled genomes can be constructed, which can then serve as a reference for predicting retrotransposon integration/restriction sites. Here we review what is known to date about retrotransposons, we discuss the involvement of viruses and retrotransposons in T1D predisposition, and finally we consider challenges in retrotransposons analysis methods.

Cascade familial hypercholesterolemia (FH) screening of parents could reduce the burden cardiovascular disease (CVD) in relatives of index cases by enabling timely diagnosis of FH. Here, we present the positive outcomes of the pilot child-parent cascade screening program in Slovenia. One hundred and thirty-eight parents from 123 families of an index child with genetically confirmed FH were randomly included in the pilot child-parent cascade screening program. Index children were identified through the universal FH screening program in preschool children. Genetic testing using Sanger sequencing was performed for cascade screening to detect (likely) pathogenic variants, previously confirmed in the index child. The success rate of confirming a (likely) pathogenic variant was 77.2 % when the first parent, preferably with higher total cholesterol levels, was tested, and reached 99.1 % when the variant was identified in the first tested parent or when both parents were tested. In the minority of cases (13.8 %), parents had had a clinical diagnosis of FH prior to their child and these had somewhat higher prevalence of CVD compared to parents that were diagnosed after their index child through the pilot program (12.5 % vs. 4.3 %; p = 0.382). In conclusion, the presented pilot child-parent cascade screening program is feasible in clinical practice and shows a high success rate in identifying parents with FH. Parents diagnosed through the program appeared to have a lower prevalence of CVD. However, larger cohorts are needed to confirm these findings.

Familial hypercholesterolemia (FH) is the most common metabolic disease, with prevalence estimated between 1:250 and 1:300. The affected individuals have a significantly higher risk for developing atherosclerosis and cardiovascular disease (CVD) compared to non-affected individuals. Early CVD can be prevented with early detection and treatment of FH. In Slovenia we have been conducting a national three-staged program of universal screening for FH of preschoolers. Goals: Our goal is to collect data for 5000 children, which is approximately one-quarter of one generation of preschoolers for the year 2023 (n = 5000). Methods: Our study includes both prospective and retrospective components and is a non-interventional cohort study. The prospective component began in 2023, when a questionnaire was distributed to multiple community health centers and outpatient practices in Slovenia. Pediatricians or school medicine specialists completed these questionnaires. The retrospective component involves our research team collecting the remaining necessary data from existing medical records. We are going to follow our algorithm for the implementation of the universal cholesterol screening program and seek all children that will be referred to the Pediatric Lipid Clinic at the University Children’s Hospital, University Medical Centre (UCH-UMC), Ljubljana, for further genetic testing. If a child has a positive genetic result, their parents and siblings will undergo genetic testing. Conclusions: Despite being a common genetic disorder, familial hypercholesterolemia (FH) is still largely underdiagnosed globally; fewer than 10% of affected individuals are thought to be identified. Early detection through effective screening is therefore essential to improve outcomes and prevent premature cardiovascular events.

Multiple familial hypercholesterolemia (FH) screening strategies are recommended, but how they work together within a population remains poorly understood. Here, we aimed to compare the characteristics of children diagnosed through a universal screening program with those of adults identified through opportunistic screening. In this retrospective cross-sectional study, we analyzed the clinical and genetic characteristics of children and adults with genetically confirmed heterozygous FH (HeFH). Out of 442 children and 299 adults with a definite or probable FH based on clinical criteria, 39 (13.0%) adults and 197 (44.6%) children had also a genetic HeFH. FH causative variants were present in low-density lipoprotein receptor (LDLR) in 159 (67.4%) patients and in apolipoprotein B (APOB) in 77 (32.6%) patients. The combined screening approach identified 44 disease-causing variants, of which 2 and 25 were unique to the adult and pediatric cohort, respectively. The proportion of children with missense variants was significantly higher (172 [87.3%] vs. 27 [69.2%]; p = 0.005), whereas the proportion of termination variants was significantly lower (20 [10.2%] vs. 11 [28.2%]; p = 0.002) compared to the adult group. Adults had higher adjusted low-density lipoprotein cholesterol compared to children. Our study suggests that opportunistic adult screening identifies more severe FH phenotypes, while universal pediatric screening detects milder cases.