Lenka Kopečková

Keratin mutations in patients with epidermolysis bullosa simplex: correlations between phenotype severity and disturbance of intermediate filament molecular structure

Background  Epidermolysis bullosa simplex (EBS) is an inherited skin disorder caused by mutations in the keratin 5 (KRT5) and keratin 14 (KRT14) genes, with fragility of basal keratinocytes leading to epidermal cytolysis and blistering.

An APEX-based genotyping microarray for the screening of 168 mutations associated with familial hypercholesterolemia.

OBJECTIVE Familial hypercholesterolemia (FH) is an inborn disorder of lipid metabolism characterised by elevated plasma concentrations of low-density lipoprotein cholesterol and total cholesterol. This imbalance results in accelerated atherosclerosis and premature coronary heart disease. The early identification and treatment of FH patients is extremely important because it leads to significant reduction of both coronary morbidity and mortality. FH is transmitted in an autosomal dominant manner and associated predominantly with mutations in the genes encoding the low-density lipoprotein receptor (LDLR) and its ligand apolipoprotein B (APOB). To date, more than 1000 sequence variants have been described in the LDLR gene. In marked contrast to LDLR, only one APOB mutation is prevalent in Europe. METHODS AND RESULTS The aim of this study was, on the basis of data obtained by the molecular genetic analysis of 1945 Czech FH probands, to propose, generate, and validate a new diagnostic tool, an APEX (Arrayed Primer EXtension)-based genotyping DNA microarray called the FH chip. The FH chip contains the APOB mutation p.Arg3527Gln, all 89 LDLR point mutations and small DNA rearrangements detected in Czech FH patients, and 78 mutations frequent in other European and Asian FH populations. The validation phase revealed the sensitivity and specificity of this platform, 100% and 99.1%, respectively. CONCLUSIONS This FH chip is a rapid, reproducible, specific, and cost-effective tool for genotyping, and in combination with MLPA (multiple ligation-dependent probe amplification) represents a reliable molecular genetic protocol for the large-scale screening of FH mutations in the Czech population.

Analysis of the COL7A1 gene in Czech patients with dystrophic epidermolysis bullosa reveals novel and recurrent mutations.

Dystrophic epidermolysis bullosa (DEB) is an inherited skin fragility disorder where blistering occurs in the sublamina densa zone at the level of anchoring fibrils of the dermo-epidermal junction zone. Both autosomal dominant (DDEB) and recessive (RDEB) forms result from mutations in the type VII collagen gene (COL7A1). The purpose of this study was to analyse the COL7A1 gene and perform genotype-phenotype correlations in Czech patients with DEB. DNA analysis of the COL7A1 gene was performed in 27 probands with diagnosis of RDEB and 6 probands with diagnosis of DDEB. 29 different sequence variants were found, ten of which have not been reported previously In the set of our RDEB patients, the most frequent mutation was the splice site mutation c.425A>G (29,6% of RDEB mutant alleles)

Ten years of DNA diagnostics of epidermolysis bullosa in the Czech Republic.

Epidermolysis bullosa (EB) is a heterogeneous group of inherited skin disorders characterized by blister formation. Classification of patients with EB begins with their separation into one of the four major EB groups, based on the level to which blisters develop: EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB) and Kindler syndrome. The next level of subclassification takes into account the clinical features present in a given patient, most notably the distribution and severity of cutaneous and extracutaneous disease involvement.

Autosomal recessive congenital ichthyoses in the Czech Republic

Autosomal recessive congenital ichthyosis (ARCI) represents a heterogeneous group of disorders of epidermal cornification. Nine genes have been identified to be causative of ARCI, including TGM1 1,2 , ABCA12 3 , NIPAL4 4 , CYP4F22 5 , ALOX12B, ALOXE3 6 , PNPLA1 7 , LIPN 8 , and CERS3 9 . ARCI is rare, with a reported prevalence 1 in 200,000 in European and northern American populations 10 . We started DNA analysis of ARCI in 2012 when PCR-direct sequencing of the TGM1, ALOX12B, ALOXE3, NIPAL4, and CYP4F22 genes was introduced and patients were analysed step by step for mutations in these genes.

Skin Lesions in a Boy With X-linked Lymphoproliferative Disorder: Comparison of 5 SH2D1A Deletion Cases

SH2D1A gene defects are the cause of X-linked lymphoproliferative disorder (XLP-1), a rare condition characterized by severe immune dysregulation. We present a patient lacking the typical symptoms of XLP-1, but experiencing a severe unusual skin condition encompassing features of dermatosclerosis and vesiculobullous skin disease. A maternal cousin of the patient was diagnosed with XLP-1 and found to carry a deletion of the SH2D1A gene. SH2D1A deletion was also identified in our patient, which offered a possible explanation for his skin symptoms. Subsequent analysis showed that the deletion in both cousins was identical and involved the whole SH2D1A gene and a part of the adjacent ODZ1 gene. High phenotypic variability of XLP-1 observed in this family prompted us to analyze the genotype-phenotype correlation of 2 different-sized deletions involving SH2D1A and ODZ1 in 5 patients from 2 families, and we report the clinical and laboratory data on these individuals. Our findings illustrate the wide clinical variability of XLP-1, both inter- and intrafamilial, which may complicate the diagnosis of this condition. The comparison of phenotypes of our patients argues against a strong involvement of the ODZ1 gene in the skin disorder and other symptoms observed in our index patient. His hitherto not described severe skin condition extends the phenotypic range of XLP-1.

Epidermolysis bullosa simplex with muscular dystrophy. Review of the literature and a case report

BACKGROUND Epidermolysis bullosa simplex associated with muscular dystrophy is a genetic skin disease caused by plectin deficiency. A case of a 19-year-old Czech patient affected with this disease and a review all previously published clinical cases are presented. MAIN OBSERVATIONS In our patient, skin signs of the disease developed after birth. Bilateral ptosis at the age of 8 years was considered as the first specific symptom of muscular dystrophy. Since then, severe scoliosis, urological and psychiatric complication have quickly developed. The signs of plectin deficiency were found by histopathological studies, electron microscopy and antigen mapping of the skin and muscular samples. Two autosomal recessive mutations in the plectin gene leading to premature termination codon were disclosed by mutation analysis. By review of all published clinical cases, 49 patients with this disease were found. 54 different mutations in the plectin gene were published, p.(Arg2319*) in exon 31 being the most frequently found. Median age of muscular dystrophy development was 9.5 years. Hoarseness and respiratory complications were the most often complications beside skin involvement. CONCLUSION Epidermolysis bullosa simplex with muscular dystrophy was diagnosed based on clinical, histopathological (skin and muscle biopsy) and mutation analysis of the plectin gene. Overview of the genetic and clinical characteristic of this disease could be presented by review of all previously published clinical cases.

A dual-fMRI investigation of the iterated Ultimatum Game reveals that reciprocal behaviour is associated with neural alignment

Dyadic interactions often involve a dynamic process of mutual reciprocity; to steer a series of exchanges towards a desired outcome, both interactants must adapt their own behaviour according to that of their interaction partner. Understanding the brain processes behind such bidirectional reciprocity is therefore central to social neuroscience, but this requires measurement of both individuals’ brains during real-world exchanges. We achieved this by performing functional magnetic resonance imaging (fMRI) on pairs of male individuals simultaneously while they interacted in a modified iterated Ultimatum Game (iUG). In this modification, both players could express their intent and maximise their own monetary gain by reciprocating their partner’s behaviour – they could promote generosity through cooperation and/or discourage unfair play with retaliation. By developing a novel model of reciprocity adapted from behavioural economics, we then show that each player’s choices can be predicted accurately by estimating expected utility (EU) not only in terms of immediate payoff, but also as a reaction to their opponent’s prior behaviour. Finally, for the first time we reveal that brain signals implicated in social decision making are modulated by these estimates of EU, and become correlated more strongly between interacting players who reciprocate one another.