RESUMEN
The aim of this work was to study the mutations within ATP7B in Egyptian children with Wilson disease and to evaluate any potential correlation between genotype and phenotype in this cohort. The study consisted of 48 children with Wilson disease from 32 independent families. The 21 exons of the ATP7B gene were amplified in a thermal cycler. Direct sequencing of the amplified polymerase chain reaction (PCR) products was performed by cycle sequencing using fluorescent dye terminators in an automatic ABI sequencer. Thirty-one different mutations in 96 chromosomes were detected (19 missense, three nonsense, seven frameshift deletions, and two splice-site mutations). Of these, 12 mutations have not been previously reported. The p.N1270S, p.C703Y, IVS18-2A > G, p.R1319X, c.2304-2305insC, and p.H1069Q were present in 7.8%, 6.2%, 6.2%, 6.2%, 4.7%, and 4.7%, respectively, of studied chromosomes in independent families. One patient was homozygous for both p.N1270S and p.T1434M mutations. Frameshift and nonsense mutations were found in 50% of patients with disease onset < or =8 years compared with only 26% in patients with onset >8 years. Despite mutation heterogeneity in Egyptian children, genotype-phenotype correlation analysis seems to be promising in this population, as many patients carry homozygous mutations, a situation that mandates a larger-scale population screening to identify the carrier rate in this community.
Asunto(s)
Adenosina Trifosfatasas/genética , Proteínas de Transporte de Catión/genética , Degeneración Hepatolenticular/genética , Mutación/genética , Adolescente , Sustitución de Aminoácidos , Niño , Codón sin Sentido , ATPasas Transportadoras de Cobre , Análisis Mutacional de ADN , Egipto , Femenino , Mutación del Sistema de Lectura , Genotipo , Humanos , Masculino , Fenotipo , Mutación Puntual , Eliminación de SecuenciaRESUMEN
Wilson's disease (WD) is a rare inborn metabolic error characterized by deficient biliary copper excretion secondary to ATP7B gene mutations. Neurological presentations are variable in respect to both pattern and age of onset; commonly a movement disorder presents in the second or third decade. The aim of this study was to ascertain genotype correlations with distinct neurological manifestations in 41 WD patients in a Brazilian center for WD. A total of 23 distinct mutations were detected, and the frameshift 3402delC had the highest allelic frequency (31.7%). An association between 3402delC and dysphagia was detected (p=0.01) but the limited number of patients is insufficient to allow one to draw conclusions. Both clinical studies analyzing larger cohorts and basic research on ATP7B protein function could potentially shed more light on our understanding of WD.
Asunto(s)
Adenosina Trifosfatasas/genética , Proteínas de Transporte de Catión/genética , Mutación del Sistema de Lectura/genética , Degeneración Hepatolenticular/genética , Degeneración Hepatolenticular/fisiopatología , Brasil , Estudios de Cohortes , ATPasas Transportadoras de Cobre , Análisis Mutacional de ADN , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Examen NeurológicoRESUMEN
We compared the effect of the p.H1069Q mutation and other non-p.H1069Q mutations in ATP7B on the phenotypic expression of Wilson's disease (WD), and assessed whether the clinical phenotype of WD in compound heterozygotes depends on the type of mutation coexisting with the p.H1069Q. One hundred forty-two patients with clinically, biochemically, and genetically diagnosed WD were studied. The mutational analysis of ATP7B was performed by direct sequencing. A total number of 26 mutations in ATP7B were identified. The p.His1069Gln was the most common mutation (allelic frequency: 72%). Seventy-three patients were homozygous for this mutation. Of compound heterozygotes, 37 had frameshift/nonsense mutation, and 20 had other missense mutation on one of their ATP7B alleles. Twelve patients had two non-p.H1069Q mutations. Patients homozygous for the p.H1069Q mutation had the less severe disturbances of copper metabolism and the latest presentation of first WD symptoms. The most severely disturbed copper metabolism and the earliest age at initial disease manifestation was noticed in non-p.H1069Q patients. In compound heterozygotes, the type of mutation coexisting with the p.H1069Q to a small extent influenced WD phenotype. The phenotype of WD varied considerably among patients with the same genotype. The p.H1069Q mutation is associated with late WD manifestation and with a mild disruption of copper metabolism. In compound heterozygotes, the phenotype of WD to a small extent depends on the type of mutation coexisting with the p.H1069Q. Besides genotype, additional modifying factors seem to determine WD manifestations.
Asunto(s)
Adenosina Trifosfatasas/genética , Proteínas de Transporte de Catión/genética , Cobre/metabolismo , Análisis Mutacional de ADN , Degeneración Hepatolenticular/genética , Adolescente , Adulto , Alelos , Ceruloplasmina/metabolismo , Niño , Aberraciones Cromosómicas , ATPasas Transportadoras de Cobre , Femenino , Frecuencia de los Genes , Genes Recesivos , Tamización de Portadores Genéticos , Genotipo , Degeneración Hepatolenticular/sangre , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Polonia , Análisis de Secuencia de ADN , Estadística como Asunto , Distribución TisularRESUMEN
AIM: To analyse the impact of NOD2/CARD15 mutations on the clinical course of Crohn's disease patients from an eastern European country (Hungary). METHODS: We investigated the prevalence of the three common NOD2/CARD15 mutations (Arg702Trp, Gly908Arg, 1007finsC) in 148 patients with Crohn's disease, 128 patients with ulcerative colitis and 208 controls recruited from the University of Szeged, Hungary. In patients with Crohn's disease, the prevalence of NOD2/CARD15 mutations was correlated to the demographical and clinical parameters. RESULTS: In total, 32.4% of Crohn's disease patients carried at least one mutant allele within NOD2/CARD15 compared to 13.2% of patients with ulcerative colitis (P = 0.0002) and to 11.5% of controls (P<0.0001). In Crohn's disease patients, the allele frequencies for Arg702Trp, Gly908Arg and 1007finsC were 7.1%, 3.0% and 10.8% respectively. Interestingly, only the 1007finsC mutation was associated with a distinct clinical phenotype. The patients positive for the 1007finsC mutation suffered more frequently from stenotic disease behaviour (P = 0.008). Furthermore, 51.9% of patients positive for the 1007finsC mutation underwent a surgical resection within the ileum compared to only 17.4% of patients without the 1007finsC mutation (P = 0.001). With respect to the other two mutations (Arg702Trp and Gly908Arg), no associations were found with all investigated clinical parameters. CONCLUSION: NOD2/CARD15 mutations are frequently found in Crohn's disease patients from Hungary. The 1007finsC mutation is associated with stenotic disease behaviour and frequent ileal resections.
Asunto(s)
Enfermedades Inflamatorias del Intestino/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Polimorfismo Genético , Adolescente , Adulto , Arginina , Constricción Patológica , Femenino , Frecuencia de los Genes , Genotipo , Glicina , Humanos , Hungría , Enfermedades Inflamatorias del Intestino/fisiopatología , Enfermedades Inflamatorias del Intestino/cirugía , Intrones , Masculino , Persona de Mediana Edad , Proteína Adaptadora de Señalización NOD2 , Fenotipo , TriptófanoRESUMEN
Wilson disease (WD) is a rare inherited autosomal recessive disorder caused by a defect in a metal transporting P-type ATPase, resulting in copper overload in various tissues and cells. The aim was to assess both the phenotype in Brazilian WD patients and the corresponding ATP7B genotype. Sixty subjects belonging to 46 pedigrees diagnosed as WD were included in this study. Direct sequencing of all 21 exons within ATP7B and their flanking introns was performed. Demographic, clinical, laboratory and histopathological data at the time of diagnosis were obtained. We identified twenty-five mutations, twelve of them reported for the first time. The c.3402delC mutation had the highest allelic frequency (30.8%), followed by the c.2123T>C (p.L708P) (16.7%). Exons 8 and 15 were the site of 62.5% of the mutations. The common European mutation c.3207C>A (p.H1069Q) was not present at all. Phenotype varied greatly among individuals with the same ATP7B genotype. Our data confirm the heterogeneity of ATP7B genotype in Brazilian WD patients. The mutational spectrum is compatible with the Brazilian history of Mediterranean immigration; however, new mutations, and different frequencies and phenotype associated with the previously known mutations characterize this population. Exons 8 and 15 should be preferentially screened in WD cases from Brazil. Phenotype variation among subjects with the same ATP7B genotype suggests that modifying factors play an additional role in the pathogenesis of WD.
Asunto(s)
Adenosina Trifosfatasas/genética , Proteínas de Transporte de Catión/genética , Degeneración Hepatolenticular/genética , Mutación , Adenosina Trifosfatasas/metabolismo , Adolescente , Adulto , Alelos , Brasil , Proteínas de Transporte de Catión/metabolismo , Niño , ATPasas Transportadoras de Cobre , Análisis Mutacional de ADN , Femenino , Genotipo , Haplotipos , Degeneración Hepatolenticular/diagnóstico , Degeneración Hepatolenticular/metabolismo , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Empalme del ARNRESUMEN
We used the denaturing gradient gel electrophoresis (DGGE) method to define mutations in the promoter region, the 18 exons, and their flanking intronic sequences of the low-density lipoprotein (LDL) receptor gene LDLR, causing familial hypercholesterolemia (FH) phenotype in 100 German and in 100 Greek hypercholesterolemic individuals. In addition, we tested all patients for the presence of mutations in codons 3456-3553 of the gene encoding apolipoprotein B-100 (APOB). Twenty-six aberrant DGGE patterns were identified and subsequently directly sequenced. In LDLR, two novel missense mutations (c.1957G>T/p.V653F, c.647 G>A/p.C216Y) and one novel homozygous base substitution c.1-156 C>T in the repeat 2 of the promoter region were identified among German FH patients; one novel splice site c.1060+10C>G was identified among Greek FH patients. One of the German FH patients was a carrier for the mutations c.1171G>A/p.A391T and p.V653F, and two of the Greek FH patients were compound heterozygotes for the mutations c.1150C>T/p.Q384X and c.1158C>G/p.D386E. Two German FH patients carried the mutation p.R3500Q within APOB. Comparing the mutations within the LDLR gene of the two European FH populations, the German population seems to be more heterogeneous than the Greek cohort. Further studies in progress are trying to elucidate the responsiveness to drug therapy in association with LDLR genotype and the nutritional habits of the two FH populations.