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Arrhythmogenic Cardiomyopathy (ACM) is an inherited cardiac disease characterized by arrhythmias and fibro-fatty replacement in the ventricular myocardium. Causative mutations are mainly reported in desmosomal genes, especially in plakophilin2 (PKP2). Here, using a virus-free reprogramming approach, we generated induced pluripotent stem cells (iPSCs) from skin fibroblasts of one ACM patient carrying the frameshift heterozygous PKP2 mutation c.2569_3018del50. The iPSC line (EURACi004-A) showed the typical morphology of pluripotent cells, possessed normal karyotype and exhibited pluripotency markers and trilineage differentiation potential, including cardiomyogenic capability. Thus, this line can represent a human in vitro model to study the molecular basis of ACM.

Mutations in the PRKN gene, encoding parkin, are the most frequent known cause of recessive Parkinson's disease (PD). We report the generation of an induced pluripotent stem cell (iPSC) line of a patient carrying a homozygous deletion of exon 3 in the PRKN gene. Skin fibroblasts were reprogrammed using non-integrating episomal plasmids. The generated cell line (EURACi005-A; iPS-2011) exhibits expression of pluripotency markers, the potential to differentiate into all three germ layers, and a stable karyotype. This iPSC line provides a valuable resource for further research on the pathomechanism and drug testing for PRKN-linked PD.

Purpose Mutations in SZT2 have been previously reported in several cases of early onset epilepsy and intellectual disability. In this study we investigate potential causal mutations in two male siblings affected by early onset epilepsy, intellectual disability and macrocephaly. Methods We use family-based whole-exome sequencing to identify candidate variants. Results We report the identification of two potential causal SZT2 mutations in compound heterozygous state. We observe considerable differences in the clinical phenotype severity of the two affected individuals. The cerebral MRI revealed no abnormalities in the older affected brother, while in the youngest one it revealed a right frontal polymicrogiria. Moreover, while good seizure control was achieved in the older affected individual the younger brother is affected by pharmacoresistant epilepsy, progressive spastic paraplegia, cortical myoclonus and a more severe intellectual disability. We also analyzed the relative location of the reported pathogenic mutations in the SZT2 protein. Conclusion Variable phenotypic expressivity is observed for this condition, while the location and type of mutations in SZT2 also has a potential impact on epilepsy severity. These findings extend our knowledge of epileptogenic conditions related to SZT2 and mTOR signaling.

Background Linkage analyses of families with primary familial brain calcification (formerly idiopathic basal ganglia calcification [IBGC]) identified 3 candidate loci (IBGC1-3). Recently, SLC20A2 mutations were found in the IBGC1 and IBGC3 families, merging these 2 loci. We here elucidate the genetic cause of primary familial brain calcification in the 'IBGC2' kindred. Methods We sequenced known primary familial brain calcification genes and quantified SLC20A2 and PDGFB. Moreover, CT scans of affected and unaffected family members were evaluated by 2 blinded neuroradiologists for distribution of brain calcification. Results A heterozygous multiexonic SLC20A2 deletion was detected in several affected family members. A reevaluation of neuroimaging data revealed a subset of mutation-negative individuals with only mild and/or unilateral calcification. Conclusions The identified SLC20A2 mutation resolves the genetic cause of primary familial brain calcification in the 'IBGC2' kindred, collapsing 'IBGC2' into IBGC1. We suggest an algorithm for predicting the chances of finding genetic mutations that has to be validated in further studies. Our study enhances criteria for the evaluation of neuroimaging data, contributing further to the much needed harmonization of diagnostic and research data collection in primary familial brain calcification. © 2016 International Parkinson and Movement Disorder Society.

Background Arrhythmogenic cardiomyopathy (ACM) is an inherited genetic disorder, characterized by the substitution of heart muscle with fibro-fatty tissue and severe ventricular arrhythmias, often leading to heart failure and sudden cardiac death. ACM is considered a monogenic disorder, but the low penetrance of mutations identified in patients suggests the involvement of additional genetic or environmental factors. Methods We used whole exome sequencing to investigate digenic inheritance in two ACM families where previous diagnostic tests have revealed a PKP2 mutation in all affected and some healthy individuals. In family members with PKP2 mutations we determined all genes that harbor variants in affected but not in healthy carriers or vice versa. We computationally prioritized the most likely candidates, focusing on known ACM genes and genes related to PKP2 through protein interactions, functional relationships, or shared biological processes. Results We identified four candidate genes in family 1, namely DAG1, DAB2IP, CTBP2 and TCF25, and eleven candidate genes in family 2. The most promising gene in the second family is TTN, a gene previously associated with ACM, in which the affected individual harbors two rare deleterious-predicted missense variants, one of which is located in the protein’s only serine kinase domain. Conclusions In this study we report genes that might act as digenic players in ACM pathogenesis, on the basis of co-segregation with PKP2 mutations. Validation in larger cohorts is still required to prove the utility of this model. Electronic supplementary material The online version of this article (10.1186/s12881-017-0503-7) contains supplementary material, which is available to authorized users.

Activated partial thromboplastin time (aPTT) and prothrombin time (PT) are clinical tests commonly used to screen for coagulation-factor deficiencies. One genome-wide association study (GWAS) has been reported previously for aPTT, but no GWAS has been reported for PT. We conducted a GWAS and meta-analysis to identify genetic loci for aPTT and PT. The GWAS for aPTT was conducted in 9,240 individuals of European ancestry from the Atherosclerosis Risk in Communities (ARIC) study, and the GWAS for PT was conducted in 2,583 participants from the Genetic Study of Three Population Microisolates in South Tyrol (MICROS) and the Lothian Birth Cohorts (LBC) of 1921 and 1936. Replication was assessed in 1,041 to 3,467 individuals. For aPTT, previously reported associations with KNG1, HRG, F11, F12, and ABO were confirmed. A second independent association in ABO was identified and replicated (rs8176704, p = 4.26 × 10(-24)). Pooling the ARIC and replication data yielded two additional loci in F5 (rs6028, p = 3.22 × 10(-9)) and AGBL1 (rs2469184, p = 3.61 × 10(-8)). For PT, significant associations were identified and confirmed in F7 (rs561241, p = 3.71 × 10(-56)) and PROCR/EDEM2 (rs2295888, p = 5.25 × 10(-13)). Assessment of existing gene expression and coronary artery disease (CAD) databases identified associations of five of the GWAS loci with altered gene expression and two with CAD. In summary, eight genetic loci that account for ∼29% of the variance in aPTT and two loci that account for ∼14% of the variance in PT were detected and supported by functional data.

Background Thyroid hormones have important roles in growth, development and control of metabolism, and their dysregulation can lead to disease. Objectives To identify genes contributing to hyperthyrotropinaemia. Design, setting, participants Linkage and association analyses using 1258 individuals from three Alpine villages. Outcome measures The study applied two different upper limits of the reference range (URR) for serum thyroid stimulating hormone (TSH) values (TSH ≥4.6 mU/l and TSH >3.0 mU/l), along with normal or low fT4 (free thyroxine) values or thyroid medical treatment to define two groups of individuals for analysis: one hyperthyrotropinaemic or high-TSH (H-TSH) (TSH ≥4.6 mU/l) group; and a larger group (TSH >3.0 mU/l) called hyperthyrotropinaemic and upper reference range TSH (H+URR-TSH). Results Non-parametric genome-wide linkage analysis was performed on pedigrees generated from the two groups. Linkage analysis in the H+URR-TSH group revealed a significant peak on chromosome 3q28-q29 (LOD 3.34) and a suggestive linkage peak on chromosome 6q26-27 (LOD 2.66). Analysis in the smaller hyperthyrotropinaemic (H-TSH) group supported linkage to chromosome 6q26-27. Single SNP and gene based SNP association analyses under the linkage peaks identified the PDE10A and DACT2 genes as candidates at the chromosome 6 locus. Conclusions PDE10A or DACT2 were identified as candidate genes contributing to hyperthyrotropinaemia (and possibly hypothyroidism) in this sample. Studies in additional populations support association of variants at this locus with TSH values, especially in the PDE10A gene. Genetic linkage in families with hyperthyrotropinaemia suggests the presence of functional variants that contribute to pathological disruption of the hypothalamus–pituitary–thyroid axis.

Based on the observed inverse association between hyperuricemia and Parkinson’s disease (PD) risk, the natural antioxidant activity of uric acid has been suggested to play a protective role. SLC2A9 has been indicated as the most effective of all uric acid transporters, and SLC2A9 variants have been shown to influence circulating uric acid levels. With this study, we aimed to test the association between such SLC2A9 polymorphisms and age at onset (AAO) of PD. Variants rs733175, rs737267, rs1014290, and rs6449213 within SLC2A9 were genotyped in 664 PD individuals from three European centers. The effect of each polymorphism on AAO was estimated within each center using a linear regression model adjusted for gender and genotype at the other SNPs and assuming an additive genetic model. Results across centers were combined using inverse-variance weighted fixed-effect meta-analysis. The minor allele of rs1014290, previously shown to be associated with lower serum uric acid levels, was found to be associated with a lower AAO of PD (pooled estimate −4.56 years; 95% CI −8.13, −1.00; p = 0.012). The association remained significant after adjustment for multiple comparisons and was highly consistent across centers (heterogeneity, I 2 0%). No gender differences were observed. Our study suggests that SLC2A9 genetic variants influence age of onset of Parkinson’s disease.

A genetic marker screening panel, ParkScreen, optimized for simultaneous marker amplification, was constructed to test or exclude linkage in families with parkinsonism or Parkinson's disease, using only a few affected individuals per family. ParkScreen functionality was proven by detection of linkage to PARK2 in a family with known Parkin mutations, exclusion of linkage to several of the known loci, and detection of suggestive linkage to PARK8, PARK3, and PARK11 in some families. In a novel approach, we also tested the ability of ParkScreen to screen patients originating from isolated populations. Using apparently sporadic patients from geographically isolated Alpine villages, suggestive linkage to PARK11 was found in one village. ParkScreen is a useful and inexpensive tool that allows the rapid screening of patients in families suitable for clinical follow-up and further characterization in order to identify specific mutations or novel genes. A genetic marker screening panel, ParkScreen, optimized for simultaneous marker amplification, was constructed to test or exclude linkage in families with parkinsonism or Parkinson's disease, using only a few affected individuals per family. ParkScreen functionality was proven by detection of linkage to PARK2 in a family with known Parkin mutations, exclusion of linkage to several of the known loci, and detection of suggestive linkage to PARK8, PARK3, and PARK11 in some families. In a novel approach, we also tested the ability of ParkScreen to screen patients originating from isolated populations. Using apparently sporadic patients from geographically isolated Alpine villages, suggestive linkage to PARK11 was found in one village. ParkScreen is a useful and inexpensive tool that allows the rapid screening of patients in families suitable for clinical follow-up and further characterization in order to identify specific mutations or novel genes. © Humana Press 2009.

Familial Idiopathic Basal Ganglia Calcification (FIBGC) is a neurodegenerative syndrome that usually follows an autosomal dominant pattern of inheritance. Linkage to only one locus on chromosome 14q (IBCG1) has been described so far. We identified and characterized a large multigenerational Italian family from a population isolate with 14 FIBGC affected members. Linkage analysis excluded the IBCG1 locus, thus demonstrating further locus heterogeneity for this disease.

Familial idiopathic basal ganglia calcification (FIBGC) is an inherited neurodegenerative disorder characterized by the accumulation of calcium deposits in different brain regions, particularly in the basal ganglia. FIBGC usually follows an autosomal dominant pattern of inheritance. Despite the mapping to chromosome 14q of a susceptibility locus for IBGC (IBCG1) in one family, this locus has been excluded in several others, demonstrating genetic heterogeneity in this disorder. The etiology of this disorder thus remains largely unknown. Using a large extended multigenerational Italian family from South Tyrol with 17 affected in a total of 56 members, we performed a genome-wide linkage analysis in which we were able to exclude linkage to the IBCG1 locus on chromosome 14q and obtain evidence of a novel locus on chromosome 2q37. Electronic supplementary material. The online version of this article (doi:10.1007/s12031-009-9287-3) contains supplementary material, which is available to authorized users.

Exposure to ionizing radiation is a well-known risk factor for a number of human cancers, including leukemia and thyroid cancer. It has been known for a long time that exposure of cells to radiation results in extensive DNA damage; however, a small number of studies have tried to explain the mechanisms of radiation-induced carcinogenesis. The high prevalence of RET/PTC rearrangements in patients who have received external radiation, and the evidence of in vitro induction of RET rearrangements in human cells, suggest an enhanced sensitivity of the RET genomic region to damage by ionizing radiation. To assess whether RET is indeed more sensitive to radiations than other genomic regions, we used a COMET assay coupled with fluorescence in situ hybridization, which allows the measurement of DNA fragmentation in defined genomic regions of single cells. We compared the initial DNA damage of the genomic regions of RET, CXCL12/SDF1, ABL, MYC, PLA2G2A, p53, and JAK2 induced by ionizing radiation in both a lymphoblastoid and a fetal thyroid cell line. In both cell lines, RET fragmentation was significantly higher than in other genomic regions. Moreover, a differential distribution of signals within the COMET was associated with a higher percentage of RET fragments in the tail. RET was more susceptible to fragmentation in the thyroid-derived cells than in lymphoblasts. This enhanced susceptibility of RET to ionizing radiation suggests the possibility of using it as a radiation exposure marker. [Cancer Res 2008;68(21):8986–92]

Genetic contributions to restless legs syndrome (RLS) have been consistently recognized from population and family studies. To determine the clinical and genetic features of RLS in a population isolate and explore linkage to three previously described susceptibility loci on chromosomes 12q, 14q, and 9p, respectively, an isolated population in the South Tyrolean Alps was identified and 530 adults participated in the study. Using a two-step strategy, 47 patients with idiopathic RLS were ascertained. The prevalence in the population was 8.9%. Twenty-eight patients (59.6%) had at least one affected first-degree relative and were classified as hereditary cases. In a single extended pedigree, linkage to known RLS loci was investigated specifying autosomal dominant and recessive models; parametric and nonparametric multipoint linkage scores were computed. None of the calculated linkage scores was suggestive of linkage between RLS and any of the three investigated loci. This study was conducted in a population isolate providing for a homogeneous genetic and environmental background. The absence of a suggestive linkage signal at the three known RLS susceptibility loci is indicative of further locus heterogeneity of this frequent disorder and encourages further studies to unveil the genetic causes of RLS. (C) 2006 Movement Disorder Society.