ABSTRACT
Studies conducted on large populations show a lack of connection between vaccination and serious neurological symptoms. However, there are isolated cases that indicate such a relationship. These reports on adverse effects following immunization (AEFI) reduce social confidence in vaccination; however, their background may be rare genetic defects. The aim of the presented study was to examine if neurological AEFI in children may be associated with variants in genes related to neurodevelopment. To identify such possible associations, a descriptive study of the Polish case series was conducted. We performed next-generation sequencing in patients who, up to 4 weeks of injection of any vaccine, manifested neurological AEFI. We included 23 previously normally developing children with first seizures that occurred after vaccination. We identified pathogenic/likely pathogenic variants in genes engaged in neurodevelopment in nine patients and variants of uncertain significance in another nine patients. The mutated genes belonged to the group of genes related to epilepsy syndromes/epileptic encephalopathy. We showed that AEFI might have a genetic background. We hypothesized that in some AEFI patients, the vaccine might only trigger neurological symptoms that would have been manifested anyway as a result of a pathogenic variant in a gene engaged in neurodevelopment.
Subject(s)
Drug-Related Side Effects and Adverse Reactions , Vaccines , Humans , Child , Poland , Immunization , Vaccination/adverse effects , Vaccines/adverse effects , Drug-Related Side Effects and Adverse Reactions/etiology , Seizures/genetics , Seizures/chemically induced , Risk Factors , Adverse Drug Reaction Reporting SystemsABSTRACT
Spontaneous abortion occurs in 8-20% of recognized pregnancies and usually takes place in the first trimester (7-11 weeks). There are many causes of pregnancy loss, but the most important (about 75%) is the presence of chromosomal aberrations. We present the results of oligonucleotide array application in a cohort of 62 miscarriage cases. The inclusion criteria for the study were the loss after 8th week of pregnancy and the appearance of recurrent miscarriages. DNA was extracted from trophoblast or fetal skin fibroblasts. In the 62 tested materials from recurrent miscarriages, the detection rate was 56.5% (35/62). The most commonly found were aneuploidies (65%) (chromosomal trisomy 14, 16, 18, 21, and 22), Turner syndrome, and triploidy (17.1%). Other chromosomal abnormalities included pathogenic and likely pathogenic structural aberrations: 1) pathogenic: deletion 7p22.3p12.3 and duplication 9p24.3p13.2 inherited from the normal father, deletion 3q13.31q22.2 and deletion 3q22.3q23 of unknown inheritance and duplication of 17p12 inherited from father with foot malformation; 2) likely pathogenic variants: deletion 17p13.1 inherited from normal mother, deletion 5q14.3 of unknown inheritance and de novo deletion 1q21.1q21.2. Among these aberrations, six CNVs (copy number variants) were responsible for the miscarriage: deletion 7p22.3p12.3 and duplication 9p24.3p13.2, deletion 3q13.31q22.2 and deletion 3q22.3q23, and deletion 17p13.1 and deletion 1q21.1q21.2. Other two findings were classified as incidental findings (deletion 5q14.3 and 17p12 duplication). Our research shows that 17% of the aberrations (6/35 abnormal results) that cannot be identified by the routine kariotype analysis are structural aberrations containing genes important for fetal development, the mutations of which may cause spontaneous abortion.
Subject(s)
Abortion, Habitual , Chromosome Aberrations , Abortion, Habitual/genetics , Comparative Genomic Hybridization , DNA Copy Number Variations/genetics , Female , Humans , Pregnancy , TrisomyABSTRACT
Actin molecules are fundamental for embryonic structural and functional differentiation; γ-actin is specifically required for the maintenance and function of cytoskeletal structures in the ear, resulting in hearing. Baraitser-Winter Syndrome (B-WS, OMIM #243310, #614583) is a rare, multiple-anomaly genetic disorder caused by mutations in either cytoplasmically expressed actin gene, ACTB (ß-actin) or ACTG1 (γ-actin). The resulting actinopathies cause characteristic cerebrofrontofacial and developmental traits, including progressive sensorineural deafness. Both ACTG1-related non-syndromic A20/A26 deafness and B-WS diagnoses are characterized by hypervariable penetrance in phenotype. Here, we identify a 28th patient worldwide carrying a mutated γ-actin ACTG1 allele, with mildly manifested cerebrofrontofacial B-WS traits, hypervariable penetrance of developmental traits and sensorineural hearing loss. This patient also displays brachycephaly and a complete absence of speech faculty, previously unreported for ACTG1-related B-WS or DFNA20/26 deafness, representing phenotypic expansion. The patient's exome sequence analyses (ES) confirms a de novo ACTG1 variant previously unlinked to the pathology. Additional microarray analysis uncover no further mutational basis for dual molecular diagnosis in our patient. We conclude that γ-actin c.542C > T, p.Ala181Val is a dominant pathogenic variant, associated with mildly manifested facial and cerebral traits typical of B-WS, hypervariable penetrance of developmental traits and sensorineural deafness. We further posit and present argument and evidence suggesting ACTG1-related non-syndromic DFNA20/A26 deafness is a manifestation of undiagnosed ACTG1-related B-WS.
Subject(s)
Actins/genetics , Deafness/genetics , Growth Disorders/genetics , Hydrocephalus/genetics , Mental Retardation, X-Linked/genetics , Mutation/genetics , Obesity/genetics , Adult , Algorithms , Base Sequence , Deafness/complications , Deafness/diagnostic imaging , Facies , Genotype , Growth Disorders/complications , Growth Disorders/diagnostic imaging , Humans , Hydrocephalus/complications , Hydrocephalus/diagnostic imaging , Magnetic Resonance Imaging , Mental Retardation, X-Linked/complications , Mental Retardation, X-Linked/diagnostic imaging , Obesity/complications , Obesity/diagnostic imaging , Pedigree , PhenotypeABSTRACT
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.
Subject(s)
Ectodermal Dysplasia , Ectodermal Dysplasia/diagnosis , Ectodermal Dysplasia/genetics , Humans , Mutation , PhenotypeABSTRACT
FRMPD4 (FERM and PDZ Domain Containing 4) is a neural scaffolding protein that interacts with PSD-95 to positively regulate dendritic spine morphogenesis, and with mGluR1/5 and Homer to regulate mGluR1/5 signaling. We report the genetic and functional characterization of 4 FRMPD4 deleterious mutations that cause a new X-linked intellectual disability (ID) syndrome. These mutations were found to be associated with ID in ten affected male patients from four unrelated families, following an apparent X-linked mode of inheritance. Mutations include deletion of an entire coding exon, a nonsense mutation, a frame-shift mutation resulting in premature termination of translation, and a missense mutation involving a highly conserved amino acid residue neighboring FRMPD4-FERM domain. Clinical features of these patients consisted of moderate to severe ID, language delay and seizures alongside with behavioral and/or psychiatric disturbances. In-depth functional studies showed that a frame-shift mutation, FRMPD4p.Cys618ValfsX8, results in a disruption of FRMPD4 binding with PSD-95 and HOMER1, and a failure to increase spine density in transfected hippocampal neurons. Behavioral studies of frmpd4-KO mice identified hippocampus-dependent spatial learning and memory deficits in Morris Water Maze test. These findings point to an important role of FRMPD4 in normal cognitive development and function in humans and mice, and support the hypothesis that FRMPD4 mutations cause ID by disrupting dendritic spine morphogenesis in glutamatergic neurons.
Subject(s)
Dendritic Spines/metabolism , Intellectual Disability/genetics , Intracellular Signaling Peptides and Proteins/genetics , Adolescent , Adult , Aged , Exons/genetics , Female , Frameshift Mutation/genetics , Humans , Male , Middle Aged , Morphogenesis/genetics , Morphogenesis/physiology , Mutation/genetics , Neurogenesis/genetics , Neurogenesis/physiology , Pedigree , Young AdultABSTRACT
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.
Subject(s)
Epidermolysis Bullosa Simplex/genetics , Keratin-5/genetics , Amino Acid Sequence , Amino Acid Substitution , Epidermolysis Bullosa Simplex/pathology , Female , Foot Dermatoses/genetics , Genetic Association Studies , Hand Dermatoses/genetics , Heterozygote , Humans , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Infant , Keratin-5/chemistry , Molecular Dynamics Simulation , Mutation, Missense , Protein Conformation , Protein Stability , Sequence Alignment , Tongue/pathologyABSTRACT
Cardio-facio-cutaneous syndrome (CFCS), a rare congenital disorder of RASopathies, displays high phenotypic variability. Complications during pregnancy and in the perinatal period are commonly reported. Polyhydramnios is observed in over half of pregnancies and might occur with fetal macrocephaly, macrosomia, and/or heart defects. Premature birth is not uncommon and any complications like respiratory insufficiency, edema, and feeding difficulties are present and might delay accurate clinical diagnosis. Besides neonatal complications, CFCS newborns and later infants have distinctive dysmorphic features usually accompanied by neurological (hypotonia with motor delay, neurocognitive delay) findings. Also, heart defects usually present at birth. Herein, we present the case of a female baby born prematurely from a pregnancy complicated with polyhydramnios, presenting at birth with craniofacial features typical for RASopathies, heart defects, neurological abnormalities, and hyperkeratosis unusual for a neonatal period. Due to the presence of a heart defect and other complications related to premature birth, the course of the disease was severe with a fatal outcome at the age of 9 months. The RASopathy, particularly CFCS, clinical diagnosis was confirmed and de novo p.Phe57Ile mutation in MAP2K2 was identified.
Subject(s)
Ectodermal Dysplasia/genetics , Ectodermal Dysplasia/pathology , Failure to Thrive/genetics , Failure to Thrive/pathology , Heart Defects, Congenital/genetics , Heart Defects, Congenital/pathology , MAP Kinase Kinase 2/genetics , Facies , Fatal Outcome , Female , Humans , Infant, Newborn , Mutation , PhenotypeABSTRACT
The presence of dynamic mutation in the FMR1 gene localized on the X chromosome (Xq28) is the major cause of Fragile X syndrome. As this syndrome is quite frequently diagnosed in patients with intellectual disability and autism spectrum disorders, the genetic testing of the FMR1 gene is a routine procedure performed in these patients. Molecular methods based on the PCR technique are used commonly, as they allow to identify normal (up to 54 CGG repeats, including grey zone alleles - 45-54 CGG repeats), premutation (55-200 CGG repeats) and full mutation (>200 CGG repeats) alleles.The article presents the basic methods used in the molecular diagnosis of Fragile X syndrome and other FMR1-related disorders. The following methods are presented: a screening test with GeneScan analysis, TP-PCR based tests and methods used for methylation analysis. Their pros and cons, as well as the resulting interpretation are discussed. Moreover, there is a presentation of the molecular diagnostic scheme following European Molecular Genetics Quality Network guidelines used in the Department of Medical Genetics.
Subject(s)
DNA Repeat Expansion , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/diagnosis , Ataxia/diagnosis , Ataxia/genetics , Female , Fragile X Syndrome/genetics , Humans , Male , Mutation , Practice Guidelines as Topic , Primary Ovarian Insufficiency/diagnosis , Primary Ovarian Insufficiency/genetics , Tremor/diagnosis , Tremor/geneticsABSTRACT
Fragile X syndrome (FXS) is the second most common inherited cause of intellectual disability (ID), after Down syndrome. The severity of ID in FXS patients varies and depends mainly on the patient's sex. Besides intellectual disorders, additional symptoms, such as psychomotor delay, a specific behavioral phenotype, or emotional problems are present in FXS patients. In over 99% of the cases, the disease is caused by the presence of a dynamic mutation in the FMR1 gene localized on the X chromosome. Due to the expansion of CGG nucleotides (over 200 repeats), FMR1 gene expression is decreased and results in the significant reduction of the FMRP protein level. The CGG expansion to premutation range (55-200 CGG repeats) is equivalent to the FXS carrier status and may cause FMR1-dependent disorders - fragile X-associated primary ovarian insufficiency (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS). In contrast to FXS, clinical symptoms of these diseases occur later in adulthood. The aim of the article is to present the knowledge about the molecular background and epidemiology of fragile X syndrome and other FMR1-related disorders.
Subject(s)
Ataxia/pathology , DNA Repeat Expansion , Fragile X Mental Retardation Protein/genetics , Fragile X Syndrome/pathology , Gene Expression Regulation , Primary Ovarian Insufficiency/pathology , Tremor/pathology , Ataxia/epidemiology , Ataxia/genetics , Ataxia/metabolism , Female , Fragile X Syndrome/epidemiology , Fragile X Syndrome/genetics , Fragile X Syndrome/metabolism , Humans , Male , Mutation , Primary Ovarian Insufficiency/epidemiology , Primary Ovarian Insufficiency/genetics , Primary Ovarian Insufficiency/metabolism , Tremor/epidemiology , Tremor/genetics , Tremor/metabolismABSTRACT
OBJECTIVES: 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. METHODS: The distribution of CTRC variants in CP pediatric cohort (nâ=â136, median age at CP onset 8 years) with no history of alcohol/smoking abuse was compared with controls (nâ=â401, median age 45). RESULTS: 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]â=â19.1; 95% CI 2.8-160; Pâ=â0.001 and ORâ=â5.5; 95% CI 1.6-19.4; Pâ=â0.001, respectively). For the first time, we demonstrated that the c.180TT genotype of common p.Gly60Gly variant is strong, an independent CP risk factor (ORâ=â23; 95% CI 7.7-70; Pâ<â0.001) with effect size comparable to p.Arg254Trp mutation. The other novel observation is that common c.493+51C>A variant, both CA and AA genotype, is significantly underrepresented in CP compared with controls (15% vs 35%; ORâ=â0.33; 95% CI 0.19-0.59; Pâ<â0.001 and 2.8% vs 11%; ORâ=â0.24; 95% CI 0.06-0.85; Pâ=â0.027, respectively). CONCLUSIONS: Our study provides evidence that CTRC variants, including c.180TT (p.Gly60Gly) are strong CP risk factors. The c.493+51C>A variant may play a protective role against CP development.
Subject(s)
Chymotrypsinogen/genetics , Genetic Predisposition to Disease , Pancreatitis, Chronic/genetics , Serine Endopeptidases/genetics , Adult , Child , Female , Genetic Variation , Genotype , Humans , Male , Pancreatitis, Chronic/diagnosis , Risk Factors , Trypsin Inhibitor, Kazal Pancreatic/geneticsABSTRACT
BACKGROUND: Available data from adult patients do not reflect natural course of hereditary pancreatitis (HP) in children. To date, no study has assessed the clinical course of HP in children. OBJECTIVE: To investigate the clinical course of HP in children and compare it to non-HP group with chronic pancreatitis (CP). METHODS: A group of 265 children with CP, hospitalized from 1988 to 2014, were enrolled in the study. Medical records of those patients were reviewed for data on presentation, diagnostic findings and treatment. All children were screened for mutations in major pancreatitis-associated genes, i.e. PRSS1, SPINK1, and CFTR. RESULTS: HP was diagnosed in 41 children (15.5%). Family history was positive in 88% of children with HP. Mutations of PRSS1 gene were found in 80% (33/41) of HP patients. We detected p.R122H, p.R122C, p.N29I, and p.E79K mutation in 34% (14/41), 27% (11/41), 12% (5/41), and 7% (3/41) of HP patients, respectively. Patients with paternal inheritance had first symptoms earlier than those with maternal inheritance (5.9 vs. 9.1 years; P < 0.05). Children with HP showed more severe changes in ERCP then those from non-HP group (2.05 Cambridge grade, vs. 1.6°; P < 0.05). ESWL was performed more frequently in HP group (12.2% vs. 3.1%; P < 0.05). There was no difference in age of disease onset (7.98 vs. 8.9 years; NS), pancreatic duct stenting (46.3% vs. 33%; NS), or number of surgical interventions (12.2% vs. 14.3%; NS) between both groups. CONCLUSIONS: Children with HP reveal significantly more severe clinical presentation of the disease than non-HP patients, despite the same age of onset.
Subject(s)
Pancreatitis/genetics , Pancreatitis/pathology , Adolescent , Age of Onset , Body Mass Index , Carrier Proteins/genetics , Child , Child, Preschool , Cohort Studies , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Disease Progression , Exons , Female , Genetic Predisposition to Disease , Humans , Infant , Male , Mutation/genetics , Pancreatic Ducts/pathology , Pancreatitis, Chronic/genetics , Pancreatitis, Chronic/pathology , Polymorphism, Restriction Fragment Length , Retrospective Studies , Trypsin/genetics , Trypsin Inhibitor, Kazal Pancreatic , Young AdultABSTRACT
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; Pâ<â0.05) and underwent surgeries more frequently (25.5% vs 8.9%; Pâ<â0.05). It could be associated with significantly longer follow-up in early onset group (median 6 vs 4 years; Pâ<â0.05). There were no differences in nutritional status or exocrine and endocrine pancreatic function. CONCLUSIONS: Early- and later-onset pancreatitis have similar etiological factors with predominance of gene mutations. The most frequent mutation found was p.Asn34Ser (N34S) in SPINK1 gene. The clinical presentation differed in number of pancreatitis episodes and frequency of surgeries.
Subject(s)
Age of Onset , Pancreatitis, Chronic/physiopathology , Adolescent , Child , Child, Preschool , Female , Genetic Predisposition to Disease , Humans , Infant , Longitudinal Studies , Male , Mutation , Pancreatitis, Chronic/etiology , Pancreatitis, Chronic/genetics , Risk FactorsABSTRACT
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 that 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 nonsynonymous 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 twofold 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.
Subject(s)
Gene Conversion , Pancreatitis, Chronic/genetics , Pseudogenes , Trypsin/genetics , Alleles , Cell Line , Child , Female , Humans , Male , Young AdultABSTRACT
OBJECTIVE: To examine the role of the IRF6 mutations in Polish families with Van der Woude syndrome and popliteal pterygium syndrome and to determine the effect of IRF6 single nucleotide polymorphisms (rs7552506, rs2013162, and rs2235375) on cleft lip and/or palate susceptibility. DESIGN: IRF6 mutation screening was performed by direct sequencing of all coding exons of the gene and their flanking intronic regions. Cosegregation analysis was performed to establish the relation of single nucleotide polymorphisms and cleft lip and/or palate phenotypes. PATIENTS: We screened the IRF6 gene in eight families with clinical recognition of Van der Woude syndrome and popliteal pterygium syndrome. RESULTS: In five families we identified pathogenic mutations, all affecting the DNA-binding or the protein-binding domain of IRF6. Two of the mutations were novel-a missense mutation Arg31Thr and a small deletion Trp40Glyfs*23. In most cases we found also a haplotype of three single nucleotide polymorphisms-rs7552506, rs2013162, and rs2235375. The association of the single nucleotide polymorphisms and cleft lip and/or palate susceptibility has been previously published. The variants did not cosegregate with phenotype in examined families nor did they cosegregate with pathogenic mutations. The single nucleotide polymorphisms were deemed not causative, due to their presence in unaffected family members. CONCLUSIONS: Two novel mutations (Arg31Thr and Trp40Glyfs*23) in the IRF6 gene were identified to be causative for Van der Woude and popliteal pterygium syndromes. In the present study no association between the single nucleotide polymorphisms rs7552506, rs2013162, and rs2235375 and the cleft lip and/or palate phenotype was found. The hypothesis, whether the haplotype of the three single nucleotide polymorphisms was correlated with IRF6 expression level, demands further investigation.
Subject(s)
Abnormalities, Multiple/genetics , Cleft Lip/genetics , Cleft Palate/genetics , Cysts/genetics , Eye Abnormalities/genetics , Fingers/abnormalities , Interferon Regulatory Factors/genetics , Knee Joint/abnormalities , Lip/abnormalities , Lower Extremity Deformities, Congenital/genetics , Polymorphism, Single Nucleotide , Syndactyly/genetics , Urogenital Abnormalities/genetics , Female , Haplotypes , Humans , Male , Mutation, Missense , Pedigree , Phenotype , PolandABSTRACT
OBJECTIVE: The aim of this study was to analyze the intra-/interfamilial phenotypic heterogeneity due to variants at the highly evolutionary conservative p.Arg1596 residue in the Nav1.1 subunit. MATERIALS/PARTICIPANTS: Among patients referred for analysis of the SCN1A gene one recurrent, heritable mutation was found in families enrolled into the study. Probands from those families even clinically diagnosed with atypical Dravet syndrome (DS), generalized epilepsy with febrile seizures plus (GEFS+), and focal epilepsy, had heterozygous p.Arg1596 His/Cys missense substitutions, c.4787G>T and c.4786C>T in the SCN1A gene. METHOD: Full clinical evaluation, including cognitive development, neurological examination, EEGs, MRI was performed in probands and affected family members in developmental age. The whole SCN1A gene sequencing was performed for all probands. The exon 25, where the identified missense substitutions are localized, was directly analyzed for the other family members. RESULTS: Mutation of the SCN1A p.1596Arg was identified in three families, in one case substitution p.Arg1596Cys and in two cases p.Arg1596His. Both mutations were previously described as pathogenic and causative for DS, GEFS+ and focal epilepsy. Spectrum of phenotypes among presented families with p.Arg1596 mutations shows heterogeneity ranged from asymptomatic cases, through FS and FS+ to GEFS+/Panayiotopoulos syndrome and epilepsies with and without febrile seizures, and epileptic encephalopathy such as DS. Phenotypes differ among patients displaying both focal and generalized epilepsies. Some patients demonstrated additionally Asperger syndrome and ataxia. CONCLUSION: Clinical picture heterogeneity of the patients carrying mutation of the same residue indicates the involvement of the other factors influencing the SCN1A gene mutations' penetrance.
Subject(s)
Epilepsies, Myoclonic/genetics , Epilepsies, Partial/genetics , NAV1.1 Voltage-Gated Sodium Channel/genetics , Adult , Child , Child, Preschool , Epilepsies, Myoclonic/physiopathology , Epilepsies, Partial/physiopathology , Female , Humans , Male , Middle Aged , Pedigree , Phenotype , Young AdultABSTRACT
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.
Subject(s)
Genetic Testing/methods , Metabolism, Inborn Errors/diagnosis , Metabolism, Inborn Errors/therapy , Neonatal Screening/methods , Humans , Incidence , Infant, Newborn , Metabolism, Inborn Errors/epidemiology , Metabolism, Inborn Errors/genetics , Rare Diseases , Risk FactorsABSTRACT
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.
Subject(s)
Carrier Proteins/genetics , Pancreatitis, Chronic/diagnosis , Pancreatitis, Chronic/genetics , Polymorphism, Genetic , Trypsin Inhibitor, Kazal Pancreatic/genetics , Adult , DNA Mutational Analysis , Female , Genetic Predisposition to Disease , Genotype , Humans , MutationABSTRACT
Mutations localized in THAP1 gene, locus 18p11.21 have been reported as causative of primary dystonia type 6 (DYT6). Disease which is characterized mainly by focal dystonia, frequently involving the craniocervical region, however associated also with early-onset generalized dystonia and spasmodic dysphonia. Here we report a novel mutation in the THAP1 gene identified in a Polish family with DYT6 phenotype - the c.15C>G substitution in exon 1 introducing the missense mutation p.Cys5Trp within the N-terminal THAP domain. The mutation was described in two generations, in patients showing a broad spectrum of focal and generalized dystonia symptoms of variable onset. Our results indicate that certain mutations in the THAP1 gene may lead to primary dystonia with remarkable intrafamilial clinical variability.
Subject(s)
Apoptosis Regulatory Proteins/genetics , DNA-Binding Proteins/genetics , Dystonic Disorders/genetics , Nuclear Proteins/genetics , Point Mutation , Family Health , Female , Genetic Variation , Humans , Male , Middle Aged , Pedigree , Phenotype , PolandABSTRACT
Prenatal diagnosis is an important element of health care in pregnant women. Until now, prenatal testing of genetically determined diseases was invasive. Identification in maternal plasma of cell-free fetal nucleic acids (cffNA) has created new opportunities, and gave rise to genetic non-invasive prenatal diagnosis (NIPD). They are three leading trends in NIPD, depending on the clinical application: analysis of hereditary diseases, analysis of aneuploidy and study of maternal-fetal conflict. In case of hereditary diseases, application of NIPD is limited to autosomal dominant disorders where the mutation is carried on the paternal allelle. It refers to problems with distinguish fetal derived cell-free DNA from maternal cell-free DNA. The important issue for using NIPD techniques in practice is to develop appropriate law regulation. This is of particular importance in the non-medical applications, when the aim of testing could be e.g. selection of fetuses. The development of effective methods for the analysis of free fetal DNA present in the mother's bloodstream is a matter of few years and show the progress made in the fields of molecular biology and medicine. It seems that non-invasive testing for a wider range of genetic disorders is a only a question of time.
ABSTRACT
Cystic fibrosis is one of the most common recessively inherited monogenic disorders in the Caucasian population. The disease develops when pathogenic mutations of the CFTR gene, encoding a transmembrane conductance regulator, are present in both alleles. Cystic fibrosis is a multi-organ disease with heterozygous clinical course. High mortality of the disease is mainly due to progressive and irreversible changes in the lungs, leading to respiratory failure. Therefore, chronic obstructive pulmonary disease is the primary target in the search for effective therapeutic solutions. In recent years there has been a significant progress in the research on early diagnosis and treatment of cystic fibrosis. The newest strategies focus not only on the main symptoms of pulmonary disease (inflammation caused by bacterial infection and obstruction due to thickened mucus), but also on the correction of the cystic fibrosis cause - defective CFTR gene and its protein product. Therapeutics like VX-770 and PTC124, intended for patients with a specific genotype, have already emerged on the U.S. and European medical market. They modulate the defective CFTR protein function or act on the level of abnormal CFTR mRNA, respectively. At the same time scientists develop new solutions in the field of somatic gene therapy in order to increase the efficiency of corrected CFTR delivery to the respiratory tract cells and to maintain its expression in the target cells. In this review we discuss the progress achieved in the development of therapy that is at the stage of both preclinical and clinical phases.