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Purpose Loss of function variants of the transient receptor potential cation channel, subfamily V, member 6 (TRPV6) have been recently associated with chronic pancreatitis (CP) in Japanese, German and French patients. Here, we investigated the association of TRPV6 variants with CP in independent European cohorts of early-onset CP patients from Poland and Germany. Patients and methods We enrolled 152 pediatric CP patients (median age 8.6 yrs.) with no history of alcohol/smoking abuse and 472 controls from Poland as well as 157 nonalcoholic young CP patients (median age 20 yrs.) and 750 controls from Germany. Coding regions of TRPV6 were screened by Sanger and next generation sequencing. Selected, potentially pathogenic TRPV6 variants were expressed in HEK293T cells and TRPV6 activity was analyzed using ratiometric Ca2+ measurements. Results Overall, we identified 10 novel (3 nonsense and 7 missenses) TRPV6 variants in CP patients. TRPV6 nonsense (p.V239SfsX53) and missense variants showing significant decrease in intracellular Ca2+ concentration in HEK293T cells (p.R174X, p.L576R, p.R342Q), were significantly overrepresented in Polish patients as compared to controls (6/152, 3.9% vs. 0/358, 0%; P = 0,0007). Nonsense TRPV6 variants predicted as loss of function (p.V239SfsX53 and p.R624X) were also significantly overrepresented in German patients (3/157; 2.0% vs 0/750; 0%, P = 0.005). Conclusions We showed that TRPV6 loss of function variants are associated with elevated CP risk in early-onset Polish and German patients confirming that TRPV6 is a novel CP susceptibility gene.

Dysplazje ektodermalne stanowią dużą grupę genetycznie uwarunkowanych chorób, które charakteryzują się spektrum objawów dotyczących struktur pochodzenia ektodermalnego (najczęściej zębów, włosów, paznokci i gruczołów potowych). Zidentyfikowano kilkadziesiąt genów, których mutacje mogą skutkować wystąpieniem określonego fenotypu. Znane jest podłoże molekularne wielu dysplazji ektodermalnych, które, jak się okazuje, często wynika z zaburzonej komunikacji w szlakach sygnałowych kluczowych dla morfogenezy zarodkowej w zakresie powstawania tkanek pochodzenia ektodermalnego lub nieprawidłowo funkcjonujących specyficznych kompleksów białkowych odpowiedzialnych za homeostazę, przyleganie i stabilność komórek w tkankach. Na podstawie powyższych danych zaproponowano odmienne podejścia klasyfikacyjne dla dysplazji ektodermalnych, w których punktem wyjścia były objawy kliniczne lub informacje o podłożu molekularnym. Rozwój technologii molekularnych pozwolił na przestrzeni lat znacznie rozszerzyć możliwości diagnostyczne dla pacjentów z objawami dysplazji ektodermalnych. Z pewnością w najbliższych latach należy się spodziewać identyfikacji nowych genów i mutacji związanych z patogenezą dysplazji ektodermalnych.

Introduction Cardiac abnormalities revealed in patients suffering from epidermolysis bullosa (EB) include dilated cardiomyopathy (DC) and aortopathy. DC is a rare but serious complication associated with an increased mortality, predominantly observed in recessive dystrophic EB. Echocardiography is the most available diagnostic tool used to detect heart disease in EB patients. Aim To analyse echocardiographic results obtained in Polish EB patients and compare them between the EB group and healthy persons. Material and methods We analysed retrospectively echocardiograms of 23 patients with EB (14 F, mean age 17.3 years) performed from 2017 to 2019. The incidence of left ventricular (LV) systolic and diastolic dysfunction, right heart disease and congenital heart disease was evaluated. A comparison of echo-parameters between EB patients and 20 matched healthy subjects was performed. Results We did not find any cases of DC and aortopathy in the EB group. One bicuspid aortic valve case was revealed. Analysis of LV diastolic parameters showed that the mean value of mitral A velocity was significantly higher and the pulmonary venous flow D velocity was lower in the EB group than in controls. Tissue Doppler analysis revealed lower values of E' velocities of mitral annulus in the EB group, what may suggest discreetly slower LV relaxation, however, this will definitely require further research. Conclusions Although most EB patients do not present cardiac symptoms, there is still a risk of developing cardiomyopathy associated with poor prognosis. It seems reasonable to perform a scheduled echocardiographic screening including LV systolic and diastolic function assessment to detect preclinical cardiac abnormalities.

Introduction Epidermolysis bullosa (EB) is a rare genetic skin disorder inherited either in autosomal recessive (AR) or autosomal dominant (AD) manner and characterized by blistering of the skin and mucous membranes. According to a subtype of EB, the oral manifestations and dental involvement vary in frequency and in severity. The most severe dental problems occur in patients with junctional epidermolysis bullosa (JEB) and severe generalized dystrophic epidermolysis bullosa (RDEB) and involve enamel erosion and development of blisters followed by painful oral wounds. Oral mucosa lesions decrease patients’ quality of life and may contribute to difficulties in nutrition leading to cachexia. Aim Assessment of efficacy of gentamicin 0.3% solution in the healing and preventing of oral erosions in patients with RDEB and evaluating its impact on the expression of type VII collagen. Material and methods The study included four female patients with RDEB, aged 16–42 who show different mutations in the COL7A1 gene and were administered the mouth rinse two times daily with a solution of 0.3% gentamycin for 4 consecutive weeks. Prior to and at the end of the study, the samples from oral mucosa were collected to estimate the expression of type VII collagen by immunofluorescence test. Results The clinical improvement of oral wounds healing and reduced number of new blisters and mucous membrane soreness as well as partial re-expression of type VII collagen was observed in all studied patients. Conclusions Topical gentamicin therapy of oral cavity in RDEB patients resulted in clinical improvement of mucosal lesions and re-expression of collagen type VII.

Introduction Mutations in the KRT1 gene encoding keratin 1 cause epidermolytic hyperkeratosis characterized by blistering in the neonatal period followed by ichthyotic hyperkeratosis in childhood and adolescent life. We observed a spectrum of clinical manifestations of blistering disorders caused by different mutations in the same KRT1 gene. Aim To analyse the phenotypic spectrum of blistering disorders caused by the KRT1 mutations. Material and methods Four patients with an epidermal barrier defect manifesting as blistering with the KRT1 mutations were included to the study. The clinical course of the disease was analysed, histology, immunofluorescence and electron microscopic examinations were performed. Results An adult patient with severe ichthyosis with p.Asn188Lys mutation in exon 1 of KRT1 who occasionally develops blisters in adolescence represents epidermolytic hyperkeratosis, a newborn child who died 4 days after birth due to disruption of the epidermal barrier (extensive blister and erosions) with mutation p.Ser193Pro in the KTR1 gene and two adult sisters harbouring heterozygous mutation c.591+1A>G in the KRT1 gene who present superficial blisters induced by mild trauma from the birth up to adolescent life without ichthyosis suggesting the diagnosis of epidermolysis bullosa simplex. Histopathology in all adult patients showed cytoplasm disruption in keratinocytes of the stratum spinosum with keratohyalin granule-like structures and, on the ultrastructural level, the presence of keratin clumping confirming the pathology of keratin intermediate filaments. Conclusions This study extends the knowledge of the clinical spectrum for the KRT1 gene mutations. This is the first description of familial dominant epidermolysis bullosa simplex linked to the KRT1 mutation.

Background: The epidermis forms the barrier between an organism and its external environment. Although one of the major functional elements of the epidermis is the lipid-enriched extracellular matrix, containing mainly ceramides, cholesterol (CHOL) and free fatty acids, the data are limited regarding the lipid profile in the epidermis. The aim of the study was to determine the whole profile of fatty acids (FAs) in the epidermis and to examine any dependence according to the age of the subject and the site on the epidermis. Materials and methods: Epidermis extracts obtained from 10 adults and 6 children were analyzed by gas chromatography-mass spectrometry. Results: In total, 74 FAs in the human epidermis were identified. We observed the highest amounts of neutral lipids (including CHOL) compared to other lipid fractions in the epidermis, regardless of age. However, we detected an age-dependent content of the major lipid fractions, where the main difference was in the levels of polyunsaturated fatty acids. There were also differences in the lipid profile between various sites of the body, e.g. samples from the breast and abdomen were enriched with very long-chain fatty acids compared to the limb. Conclusion: Our research provides novel data concerning the lipid profile in the epidermis, gives further insight into skin biology and proves that the epidermis is a highly dynamic structure.

Aromatic amino acid decarboxylase (AADC) deficiency is a rare monogenic disease, often fatal in the first decade, causing severe intellectual disability, movement disorders and autonomic dysfunction. It is due to mutations in the gene coding for the AADC enzyme responsible for the synthesis of dopamine and serotonin. Using whole exome sequencing, we have identified a novel homozygous c.989C > T (p.Pro330Leu) variant of AADC causing AADC deficiency. Pro330 is part of an essential structural and functional element: the flexible catalytic loop suggested to cover the active site as a lid and properly position the catalytic residues. Our investigations provide evidence that Pro330 concurs in the achievement of an optimal catalytic competence. Through a combination of bioinformatic approaches, dynamic light scattering measurements, limited proteolysis experiments, spectroscopic and in solution analyses, we demonstrate that the substitution of Pro330 with Leu, although not determining gross conformational changes, results in an enzymatic species that is highly affected in catalysis with a decarboxylase catalytic efficiency decreased by 674- and 194-fold for the two aromatic substrates. This defect does not lead to active site structural disassembling, nor to the inability to bind the pyridoxal 5’-phosphate (PLP) cofactor. The molecular basis for the pathogenic effect of this variant is rather due to a mispositioning of the catalytically competent external aldimine intermediate, as corroborated by spectroscopic analyses and pH dependence of the kinetic parameters. Altogether, we determined the structural basis for the severity of the manifestation of AADC deficiency in this patient and discussed the rationale for a precision therapy.

Background Skin lesions on the feet and foot deformities impair daily activities and decrease quality of life. Although substantial foot deformities occur in many genodermatoses, few reports have been published on this topic. Therefore, we performed a retrospective chart review to identify patients with genodermatoses and foot disorders. We included 16 patients, who were investigated clinically and with molecular biology. Results The following genodermatoses with foot deformities were detected: autosomal recessive congenital ichthyosis (ARCI, n = 7); palmoplantar keratodermas (PPKs, n = 6); ichthyosis follicularis, atrichia, and photophobia (IFAP, n = 1); ectrodactyly-ectodermal dysplasia-clefting (EEC, n = 1); and ichthyosis with confetti (IWC, n = 1). Foot problems not only varied in severity depending on the disease but also showed phenotypic heterogeneity among patients with the same condition. Foot deformities were most pronounced in patients with EEC (split foot) or IWC (contractures) and less severe in those with ARCI (clawed toes), IFAP (hollow feet), or PPK (no bone abnormalities in the feet). Conclusion Because a range of distinct genodermatoses involve foot abnormalities, early rehabilitation and other corrective measures should be provided to patients with foot involvement to improve gait and prevent/delay irreversible complications.

Hailey-Hailey disease (HHD) is a rare, late-onset autosomal dominant genodermatosis characterized by blisters, vesicular lesions, crusted erosions, and erythematous scaly plaques predominantly in intertriginous regions. HHD is caused by ATP2C1 mutations. About 180 distinct mutations have been identified so far; however, data of only few cases from Central Europe are available. The aim was to analyze the ATP2C1 gene in a cohort of Polish HHD patients. A group of 18 patients was enrolled in the study based on specific clinical symptoms. Mutations were detected using Sanger or next generation sequencing. In silico analysis was performed by prediction algorisms and dynamic structural modeling. In two cases, mRNA analysis was performed to confirm aberrant splicing. We detected 13 different mutations, including 8 novel, 2 recurrent (p.Gly850Ter and c.325-3 T > G), and 6 sporadic (c.423-1G > T, c.899 + 1G > A, p.Leu539Pro, p.Thr808TyrfsTer16, p.Gln855Arg and a complex allele: c.[1610C > G;1741 + 3A > G]). In silico analysis shows that all novel missense variants are pathogenic or likely pathogenic. We confirmed pathogenic status for two novel variants c.325-3 T > G and c.[1610C > G;1741 + 3A > G] by mRNA analysis. Our results broaden the knowledge about genetic heterogeneity in Central European patients with ATP2C1 mutations and also give further evidence that careful and multifactorial evaluation of variant pathogenicity status is essential.

Objectives It has previously been reported in a European case-control study with patients from Germany and France that CEL-HYB1, a hybrid allele of the carboxyl ester lipase (CEL) gene and its pseudogene CELP, increases susceptibility to chronic pancreatitis (CP). Here, we aimed to replicate this finding in Polish pediatric patients with CP. Method The distribution of the CEL-HYB1 allele in a CP pediatric cohort (n = 147, median age at CP onset 7.6 years) with no history of alcohol/smoking abuse was compared with ethnically matched healthy controls (n = 500, median age 46 years). Screening was performed using long-range PCR followed by agarose gel-electrophoresis. Results We observed no significant difference in the carrier frequency of the CEL-HYB1 allele between CP patients (7/147, 4.8%) and controls (12/500, 2.4%; P = 0.16). Conclusions This study found no statistically significant association between CEL-HYB1 and chronic pancreatitis in a cohort of Polish pediatric CP patients.

Ectodermal dysplasias are a wide group of genetic disorders characterised by clinical symptoms in ectodermal derivatives (most frequently teeth, hair, nails and sweat glands). There is a number of genes, which, if mutated, can cause the specified phenotype. The molecular basis of many ectodermal dysplasias have been investigated. The phenotype often results from the imparied communication in molecular pathways important in embryonic morphogenesis or disturbed function of protein complexes involved in homeostasis, adhesion and stability of the cells in the tissue. Different classification systems have been proposed to group ectodermal dysplasias according to clinical symptoms or molecular basis. Molecular technologies have let recently to expand diagnostic abilities for ectodermal dysplasias patients. Certainly in the nearest years new genes and mutations will be discovered as a cause of ectodermal dysplasias.Dysplazje ektodermalne stanowią dużą grupę genetycznie uwarunkowanych chorób, które charakteryzują się spektrum objawów dotyczących struktur pochodzenia ektodermalnego (najczęściej zębów, włosów, paznokci i gruczołów potowych). Zidentyfikowano kilkadziesiąt genów, których mutacje mogą skutkować wystąpieniem określonego fenotypu. Znane jest podłoże molekularne wielu dysplazji ektodermalnych, które, jak się okazuje, często wynika z zaburzonej komunikacji w szlakach sygnałowych kluczowych dla morfogenezy zarodkowej w zakresie powstawania tkanek pochodzenia ektodermalnego lub nieprawidłowo funkcjonujących specyficznych kompleksów białkowych odpowiedzialnych za homeostazę, przyleganie i stabilność komórek w tkankach. Na podstawie powyższych danych zaproponowano odmienne podejścia klasyfikacyjne dla dysplazji ektodermalnych, w których punktem wyjścia były objawy kliniczne lub informacje o podłożu molekularnym. Rozwój technologii molekularnych pozwolił na przestrzeni lat znacznie rozszerzyć możliwości diagnostyczne dla pacjentów z objawami dysplazji ektodermalnych. Z pewnością w najbliższych latach należy się spodziewać identyfikacji nowych genów i mutacji związanych z patogenezą dysplazji ektodermalnych.

Classic galactosemia (OMIM #230400) is an autosomal recessive disorder caused by homozygous or compound heterozygous pathogenic variants in the galactose-1-phosphate uridylyltransferase gene (GALT; 606999) on chromosome 9p13. Its diagnosis is established by detecting elevated erythrocyte galactose-1-phosphate concentration, reduced erythrocyte galactose-1-phosphate uridylyltransferase (GALT) enzyme activity. Biallelic pathogenic variants in the GALT gene is confirmed by DNA analysis. Our paper presents molecular characteristics of 195 Polish patients diagnosed with galactosemia I, intending to expand the current knowledge of this rare disease's molecular etiology. To the best of our knowledge, the described cohort of galactosemia patients is the largest single-center cohort presented so far. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01869-3.

Background Large and giant congenital melanocytic nevi (CMN), benign naevomelanocytic proliferations derived from neural crests, with a projected adult size (PAS) ≥ 20 cm, are connected to a high risk of melanoma and neurocutaneous melanosis. Among several factors, genetic alterations seem to be involved in tumorigenesis. The aim of the present study was to analyse the mutation status of NRAS and BRAF genes in resection specimens from large or giant CMN in a group of Polish patients. Material and methods The formalin-fixed, paraffin-embedded resection specimens from 18 patients, fixed in the years of 2006 to 2017, were included in the study. The regions containing the highest load of melanocytes were macrodissected prior to DNA isolation. The NRAS and BRAF mutation status was evaluated using qPCR. Results We detected activating mutations in NRAS gene (codons: 12 and 61) in 7 out of the 18 (38.9%) patients. No BRAF mutations were found. Conclusion Our study, the first molecular analysis of large/giant CMN in Polish patients, supports the hypothesis that NRAS mutation in codon 61 are frequent, recurrent mutations in large/giant CMN. Moreover, we show, for the first time, that NRAS mutations in codon 12 (p.Gly12Asp) can be also detected in giant CMN. The exact role of these genetic alterations in CMN formation remains to be elucidated.

Chronic pancreatitis (CP) is a rare disease in children. We describe the first case of a 3-year-old Caucasian patient with CP with the presence of a homozygous pathogenic variant c.194 + 2T > C in serine protease inhibitor, Kazal type 1 (SPINK1) and pancreas divisum.

Genetycznie uwarunkowane choroby skóry, genodermatozy, stanowią grupę rzadko występujących chorób o wysoce zróżnicowanym przebiegu klinicznym, rokowaniu izłożonej patologii molekularnej. Pęcherzowe oddzielanie się naskórka (EB) i zaburzenia rogowacenia o dziedziczeniu Mendlowskim (MeDOC) to genodermatozy, w których dochodzi do zaburzeń funkcjonowania naskórka. Zidentyfikowano już kilkadziesiąt genów przyczynowo związanych z występowaniem objawów klinicznych, a więc, w ogólnym ujęciu, tendencji do tworzenia pęcherzy i nadmiernej podatności skóry na urazy w przypadku EB oraz nieprawidłowego rogowacenia w MeDOC. Objawy kliniczne tych chorób mogą być jednak bardzo zróżnicowane, a zależności genotypowo-fenotypowe określone zostały tylko częściowo. Diagnostyka molekularna, której celem jest identyfikacja mutacji u poszczególnych pacjentów umożliwia weryfikację rozpoznania klinicznego, określenie ryzyka powtórzenia się choroby w rodzinie, a stopniowo także podstawę do opracowania nowych terapii. Jednakże, nawet nowoczesne technologie analizy molekularnej pozwalają na wykrycie mutacji tylko u 80% chorych. Określenie patologii molekularnej w przypadku pozostałych pacjentów oraz opracowanie skutecznych terapii wymaga dalszych, interdyscyplinarnych badań naukowych.

Genetic studies in adults/adolescent patients with chronic pancreatitis (CP) identified chymotrypsinogen C (CTRC) genetic variants but their association with CP risk has been difficult to replicate. To evaluate the risk of CP associated with CTRC variants in CP pediatric patients-control study.The distribution of CTRC variants in CP pediatric cohort (n = 136, median age at CP onset 8 years) with no history of alcohol/smoking abuse was compared with controls (n = 401, median age 45).We showed that p.Arg254Trp (4.6%) and p.Lys247_Arg254del (5.3%) heterozygous mutations are frequent and significantly associated with CP risk in pediatric patients (odds ratio [OR] = 19.1; 95% CI 2.8-160; P = 0.001 and OR = 5.5; 95% CI 1.6-19.4; P = 0.001, respectively). For the first time, we demonstrated that the c.180TT genotype of common p.Gly60Gly variant is strong, an independent CP risk factor (OR = 23; 95% CI 7.7-70; P 0.001) with effect size comparable to p.Arg254Trp mutation. The other novel observation is that common c.493+51CA variant, both CA and AA genotype, is significantly underrepresented in CP compared with controls (15% vs 35%; OR = 0.33; 95% CI 0.19-0.59; P 0.001 and 2.8% vs 11%; OR = 0.24; 95% CI 0.06-0.85; P = 0.027, respectively).Our study provides evidence that CTRC variants, including c.180TT (p.Gly60Gly) are strong CP risk factors. The c.493+51CA variant may play a protective role against CP development.

Usher syndrome is rare genetic disorder impairing two human senses, hearing and vision, with the characteristic late onset of vision loss. This syndrome is divided into three types. In all cases, the vision loss is postlingual, while loss of hearing is usually prelingual. The vestibular functions may also be disturbed in Usher type 1 and sometimes in type 3. Vestibular areflexia is helpful in making a proper diagnosis of the syndrome, but, often, the syndrome is misdiagnosed as a nonsyndromic hearing loss. Here, we present a Polish family with hearing loss, which was clinically classified as nonsyndromic. After excluding mutations in the DFNB1 locus, we implemented the next-generation sequencing method and revealed that hearing loss was syndromic and mutations in the USH2A gene indicate Usher syndrome. This research highlights the importance of molecular analysis in establishing a clinical diagnosis of congenital hearing loss.

Introduction More than 2000 mutations have been identified since the discovery of the CFTR gene in 1989. However, only 346 mutations have been classified as cystic fibrosis (CF)-causing mutations. Due to the increasing number of mutations and poor correlation between the genotype and phenotype, there is an urgent need to determine the mutations that are pathogenic, nonpathogenic, or lead to variable symptoms. Aim The aim of the study was to present the clinical characteristics of Polish patients with rare and novel CFTR mutations, with an attempt to determine the pathogenicity status of those variants. Materials and methods The group included 13 patients born between September 2006 and May 2019, who underwent CF newborn screening and in whom two CFTR mutations, including at least one rare or a novel mutation, were identified. Results We identified 13 patients with mutations in both alleles of the CFTR gene, one of which was at least rare in Polish population (R289NfsX17, I618RfsX2, T682KfsX40, S1347PfsX13, W356X, E33X, dup.16,17A) or was a mutation of unknown clinical consequences (H199R, L468P, A1217E, Q359R, T1036I, W1282R). None of them were described in the CFTR2 database. In all examined patients, sweat tests were elevated. The diagnosed patients presented with a wide spectrum of clinical symptoms. Broad clinical characteristics and test results are presented. Conclusion Pathogenic mutations are H199R, L468P, A1217E, Q359R, T1036I, W1282R, R289NfsX17, I618RfsX2, T682KfsX40, S1347PfsX13, W356X, E33X, dup.16,17A. Every patient with a mutation of unknown clinical consequences in one CFTR allele requires attentive follow-up.

Chronic pancreatitis (CP) is a progressive, irreversible inflammatory disorder of the pancreas, which results from interrelations between different genetic and environmental factors. Genetic variants are the primary cause of the disease in early-onset nonalcoholic CP patients. Novel CP-associated genes are continuously emerging from genetic studies on CP cohorts, providing important clues for distinct mechanisms involved in CP development. On the basis of functional studies, the genetic alterations have been sub-grouped into CP-driving pathological pathways. This review focuses on the concept of CP as a complex disease driven by multiple genetic factors. We will discuss only well-defined genetic risk factors and distinct functional pathways involved in CP development, especially in the context of the early-onset nonalcoholic CP group. The diagnostic implications of the genetic testing will be addressed as well.

Usher syndrome (USH) is the most common form of simultaneous loss of hearing and vision. USH is autosomal recessive disorder, clinically and genetically heterogenous. It is characterised by congenital sensorineural hearing loss, retinitis pigmentosa and in some cases by vestibular defect. Based on the symptoms observed in patients, USH is classified into three types (1, 2 and 3). To date, eleven genes with causative mutations have been identified. Proteins encoded by these genes are part of a functional complex which is present in humans hair cells in the inner ear and in photoreceptor cells in the retina. This complex is the most important in the development of the stereocilia and it is essential in a proper functioning of calyceal processes in photoreceptor cells. Disruption of proteins involved in this complex leads to Usher syndrome. In this review, we focus on molecular pathophysiology of USH with an emphasis on USH etiology, genotype–phenotype correlation, characterization of USH genes, protein complexes and their functions in human tissues.

Genetically determined skin diseases, genodermatoses, are a group of rare disorders characterized by heterogeneous clinical course, prognosis and complex molecular pathology. In Epidermolysis Bullosa (EB) and Mendelian disorders of cornification (MeDOC) epidermal dysfunction occurs. Mutations in several dozen genes have been identified to be responsible for clinical symptoms of EB and MeDOC, which, in general, include: tendency to blister formation with skin fragility and abnormal keratinization, respectively. However, clinical symptoms of these diseases can be variable and genotype-phenotype correlations are only partially determined. Molecular diagnostics aimed at identification of mutations in affected individuals enables verification of clinical diagnosis, calculation of disease recurrence risk in other family members and, gradually, is also the basis for new therapies development. Nevertheless, even modern molecular technologies allow mutation detection in 80% of patients only. Hence, further, interdisciplinary scientific research are needed in order to increase detection rate and develop effective therapies.Genetycznie uwarunkowane choroby skóry, genodermatozy, stanowią grupę rzadko występujących chorób o wysoce zróżnicowanym przebiegu klinicznym, rokowaniu i złożonej patologii molekularnej. Pęcherzowe oddzielanie się naskórka (EB) i zaburzenia rogowacenia o dziedziczeniu Mendlowskim (MeDOC) to genodermatozy, w których dochodzi do zaburzeń funkcjonowania naskórka. Zidentyfikowano już kilkadziesiąt genów przyczynowo związanych z występowaniem objawów klinicznych, a więc, w ogólnym ujęciu, tendencji do tworzenia pęcherzy i nadmiernej podatności skóry na urazy w przypadku EB oraz nieprawidłowego rogowacenia w MeDOC. Objawy kliniczne tych chorób mogą być jednak bardzo zróżnicowane, a zależności genotypowo-fenotypowe określone zostały tylko częściowo. Diagnostyka molekularna, której celem jest identyfikacja mutacji u poszczególnych pacjentów umożliwia weryfikację rozpoznania klinicznego, określenie ryzyka powtórzenia się choroby w rodzinie, a stopniowo także podstawę do opracowania nowych terapii. Jednakże, nawet nowoczesne technologie analizy molekularnej pozwalają na wykrycie mutacji tylko u 80% chorych. Określenie patologii molekularnej w przypadku pozostałych pacjentów oraz opracowanie skutecznych terapii wymaga dalszych, interdyscyplinarnych badań naukowych.

Epidermolysis bullosa simplex (EBS) is a hereditary genodermatosis characterised by trauma-induced intraepidermal blistering of the skin. EBS is mostly caused by mutations in the KRT5 and KRT14 genes. Disease severity partially depends on the affected keratin type and may be modulated by mutation type and location. The aim of our study was to identify the molecular defects in KRT5 and KRT14 in a cohort of 46 Polish and one Belarusian probands with clinical suspicion of EBS and to determine the genotype–phenotype correlation. The group of 47 patients with clinical recognition of EBS was enrolled in the study. We analysed all coding exons of KRT5 and KRT14 using Sanger sequencing. The pathogenic status of novel variants was evaluated using bioinformatical tools, control group analysis (DNA from 100 healthy population-matched subjects) and probands’ parents testing. We identified mutations in 80 % of patients and found 29 different mutations, 11 of which were novel and six were found in more than one family. All novel mutations were ascertained as pathogenic. In the majority of cases, the most severe genotype was associated with mutations in highly conserved regions. In some cases, different inheritance mode and clinical significance, than previously reported by others, was observed. We report 11 novel variants and show novel genotype–phenotype correlations. Our data give further insight into the natural history of EBS molecular pathology, epidemiology and mutation origin.

Mutations of the human cationic trypsinogen gene (PRSS1) are frequently found in association with hereditary pancreatitis. The most frequent variants p.N29I and p.R122H are recognized as disease-causing mutations. Three pseudogene paralogs in the human trypsinogen family, including trypsinogen 6 (PRSS3P2), carry sequence variations in exon 3 which mimic the p.R122H mutation. In routine genetic testing of patients with chronic pancreatitis we identified in two unrelated individuals similar gene conversion events of 24–71 nucleotides length between exon 3 of the PRSS1 (acceptor) and PRSS3P2 (donor) genes. The converted allele resulted in three non-synonymous alterations c.343T>A (p.S115T), c.347G>C (p.R116P) and c.365_366delinsAT (p.R122H). Functional analysis of the conversion triple mutant revealed markedly increased autoactivation resulting in high and sustained trypsin activity in the presence of chymotrypsin C. This activation phenotype was identical to that of the p.R122H mutant. In addition, cellular secretion of the triple mutant from transfected HEK 293T cells was increased about two-fold and this effect was attributable to mutation p.R116P. Our observations confirm and extend the notion that recombination events between members of the trypsinogen family can generate high risk PRSS1 alleles. The pathogenic phenotype of the novel conversion is explained by a unique combination of increased trypsinogen activation and secretion.

Epidermolysis bullosa is a group of inherited blistering skin diseases resulting in most cases from missense mutations in KRT5 and KRT14 genes encoding the basal epidermal keratins 5 and 14. Here, we present a patient diagnosed with a localized subtype of epidermolysis bullosa simplex caused by a heterozygous mutation p.Ala428Asp in the KRT5 gene, that has not been previously identified. Moreover, a bioinformatic analysis of the novel mutation was performed, showing changes in the interaction network between the proteins. Identification of novel mutations and genotype-phenotype correlations allow to better understanding of underlying pathophysiologic bases and is important for genetic counselling, patients' management, and disease course prediction.

About 75% of cases of epidermolysis bullosa simplex result from mutations in KRT5 and KRT14 genes. Here, we report a family with a novel heterozygous missense mutation p.Leu418Gln in the KRT14 gene causing EBS of phenotype varying from EBS-loc to EBS-gen intermed. To the best of our knowledge, the family reported by us is the largest one in which two different phenotypes can be distinguished. The molecular dynamics simulations show that p.Leu418Gln mutation results in clear disruption of intermolecular π-stacking between KRT14:Tyr415 and KRT5:Tyr470, which in turn may affect putative phosphorylation site at KRT14:Thr414. This study further supports the importance of the EIATYR/KLLEGE motif in maintaining structural stability of KRT14:KRT5 heterodimer and indicates that physical properties of introduced amino acid can modulate the disease severity. The results obtained indicate further need of genotype-phenotype studies in EBS. In conclusion, genotype-based prognosis should be given to patients with caution.

We read with great interest the recent publication by Nemeth et al .1 in which the authors demonstrate that a misfolding human cationic trypsinogen (serine protease 1, PRSS1) variant causes autosomal dominant hereditary chronic pancreatitis (CP) by inducing endoplasmic reticulum (ER) stress. Previously, the same mechanism was proposed for carboxypeptidase A1 ( CPA1 ) gene variants strongly associated with early onset sporadic CP;2 however, the association of misfolding CPA1 variants with familial or hereditary CP has not been demonstrated so far. Here, we report two Polish families with hereditary CP carrying a novel heterozygous c.844T>C (p.Ser282Pro) CPA1 variant. In Family 1, the index patient, her mother and uncle (half-brother of the mother) developed CP (figure 1). The age of diagnosis was 17 years for the index patient and 51 and 31 years (with earlier abdominal pain) for the mother and the uncle, respectively. In Family 2, three members were affected by CP (figure 1): the index patient, her mother and her father with ages of onset of 12, 32 and 34 years, respectively. In both families, the diagnosis of CP was confirmed by …

OBJECTIVES The etiological factors of chronic pancreatitis (CP) in children differ from those in adults. To date, no study has assessed the clinical course of CP in young children. The aim of our study was to evaluate the etiology and the clinical presentation of the disease in children with disease onset before 5 years of age in comparison to later-onset of CP. METHODS A total of 276 children with CP, hospitalized from 1988 to 2015, were enrolled in the study. Data on presentation, diagnostic findings, and treatment were reviewed. Two hundred sixty patients were screened for the most frequent mutations in major pancreatitis-associated genes, such as cationic trypsinogen/serine protease gene (PRSS1), serine protease inhibitor, Kazal type 1 gene (SPINK1), and cystic fibrosis transmembrane conductance regulator gene (CFTR). RESULTS The disease onset before the age of 5 years occurred in 51 patients (group 1), the later onset in 225 patients (group 2). We found no significant discrepancies in distribution of the etiological factors between groups. The youngest patients (group 1) had more pancreatitis episodes (median 5.0 vs 3.00; P

The need for Locus-Specific Databases, with disease-specific experts and curators, is an essential ingredient in a process to enable the benefits of the advances in sequencing and mutational analysis to be realized across the genome. Next generation sequencing provides both astounding opportunities and challenges, especially for genetic counsellors. An approach coordinated at a genome wide, international level, supported by well-organized disease-specific respected organizations is a model most likely to be successful, but committed resourceful professionals working in local poorly resourced environments can make valuable contributions that can grow. Bioinformatic tools to sift and integrate multiple domains of information are being developed, and play a major part in meeting the challenges. Regulation of providers, including a requirement for them to submit mutational information to central databases, also should assist to reach the goals needed to realize the opportunities. There is also a need to agree on governance of Locus-Specific Databases (LSDBs) at an international level, and for adequate international funding to support this need, to ensure humanity reaps the benefits of the current molecular genetic revolution. The Human Variome Project offers this, working also with the other major initiatives with similar objectives. This report concludes with Recommendations for the Human Variome Project stemming from the presentations and discussions at the meeting. (c) 2012 Wiley Periodicals, Inc.

Newborn screening for cystic fibrosis (NBS CF) in Poland was started in September 2006. Summary from 4 years' experience is presented in this study. The immunoreactive trypsin/DNA sequencing strategy was implemented. The group of 1,212,487 newborns were screened for cystic fibrosis during the programme. We identified a total of 221 CF cases during this period, including, 4 CF cases were reported to be omitted by NBS CF. Disease incidence in Poland based on the programme results was estimated as 1/4394 and carrier frequency as 1/33. The frequency of the F508del was similar (62%) to population data previously reported. This strategy allowed us to identify 29 affected infants with rare genotypes. The frequency of some mutations (eg, 2184insA, K710X) was assessed in Poland for the first time. Thus, sequencing assay seems to be accurate method for screening programme using blood spots in the Polish population.

Keratin disorders are a group of rare bullous skin diseases. They are caused by mutations in genes encoding keratins – the main structural proteins of intermediate filament cytoskeleton of epithelial cells and also one of the major components of hair and nails. Different pairs of keratins are the expressed depending on the skin layer, thus variability in the course of keratinopathies is observed. This disorders are inherited in autosomal dominant pattern mostly. Mutations occur in different regions of the keratin genes. In most of these diseases correlation between the location of mutations, and the severity of clinical symptoms can be observed. The most common keratin disorder is epidermolysis bullosa simplex (EBS), which is caused by mutations in KRT5 and KRT14. These genes are expressed in basal layer of epidermal cells. Depending on the effect of the molecular defect in the protein, EB simplex can phenotype of EBS may be highly different - from mild and localized forms, to severe and generalized. Another disease from this group is epidermolytic ichthyosis, which is caused by mutations in KRT1 and KRT10, expressed in epidermal suprabasal cell layer. This paper contains an overview of selected keratin disorders in terms of their molecular pathology. Beside those mentioned above, ichthyosis bullosa of Siemiens, pachyonychia congenita, and Dowling-Degos disease are also described.

Inherited metabolic disorders, also referred to as inborn errors of metabolism (IEM), are a group of congenital disorders caused by mutation in genomic or mitochondrial DNA. IEM are mostly rare disorders with incidence ranging from 1/50,000-1/150,000), however in total IEM may affect even 1/1000 people. A particular mutation affects specific protein or enzyme that improper function leads to alterations in specific metabolic pathway. Inborn errors of metabolism are monogenic disorders that can be inherited in autosomal recessive manner or, less frequently, in autosomal dominant or X-linked patterns. Some exceptions to Mendelian rules of inheritance have also been described. Vast majority of mutations responsible for IEM are small DNA changes affecting single or several nucleotides, although larger rearrangements were also identified. Therefore, the methods used for the identification of pathogenic mutations are mainly based on molecular techniques, preferably on Sanger sequencing. Moreover, the next generation sequencing technique seems to be another prospective method that can be successfully implemented for the diagnosis of inborn errors of metabolism. The identification of the genetic defect underlying the disease is not only indispensable for genetic counseling, but also might be necessary to apply appropriate treatment to the patient. Therapeutic strategies for IEM are continuously elaborated and tested (eg. enzyme replacement therapy, specific cells or organ transplantation or gene therapy, both in vivo and ex vivo) and have already been implemented for several disorders. In this article we present current knowledge about various aspects of IEM on the basis of our own experience and literature review.

Chronic pancreatitis (CP) is characterized by progressive damage to the exocrine and endocrine cell structures and pancreatic ducts with subsequent fibrosis of the organ. Patients with no apparent etiological factor are classified as having idiopathic CP (ICP). Genetic studies indicate the importance of mutations in the serine protease inhibitor, Kazal type 1 gene (SPINK1) in the pathogenesis of CP This report describes a case of a 29-year-old Polish-Vietnamese patient with the p.Asn34Ser (p.N34S) homozygous mutation in the SPINK1 gene. The patient was hospitalized due to pain of average intensity in the epigastric area which occurred for the first time in his life. Imaging examination showed the atrophy of the pancreatic parenchyma with the presence of numerous small calcifications and a single calcified lodgement with a diameter of 22 mm in the distal segment of Wirsung 's duct. Clinical interview did not reveal any obvious etiological pancreatitis risk factors implying the causative role of the p.Asn34Ser homozygous mutation of SPINK1 in this case as proven in our investigation.