RESUMEN
Cerebral cavernous malformations (CCMs) are a diffuse cerebrovascular disease affecting approximately 0.5% of the population. A CCM is characterized by abnormally enlarged and leaky capillaries arranged in mulberry-like structures with no clear flow pattern. The lesion might predispose to seizures, focal neurological deficits or fatal intracerebral hemorrhage. However, a CCM can also remain neurologically silent. It might either occur sporadically or as an inherited disorder with incomplete penetrance and variable expressivity. Due to advances in imaging techniques, the incidence of CCM diagnoses are increasing, and the patient must be managed on a multidisciplinary basis: genetic counselling, treatment if needed, and follow-up. Advances have been made using radiological and pathological correlates of CCM lesions adding to the accumulated knowledge of this disease, although management of these patients is very variable among centers. This review is aimed at providing an update in genetic and molecular insights of this condition. Included are implications for genetic counselling, and possible approaches to prevention and treatment that derive from the understanding of pathogenetic mechanisms.
Asunto(s)
Encéfalo , Sistema Nervioso Central/patología , Hemangioma Cavernoso del Sistema Nervioso Central , Proteínas Asociadas a Microtúbulos , Proteínas Proto-Oncogénicas , Encéfalo/metabolismo , Encéfalo/patología , Sistema Nervioso Central/metabolismo , Hemorragia Cerebral/genética , Hemorragia Cerebral/patología , Asesoramiento Genético , Hemangioma Cavernoso del Sistema Nervioso Central/diagnóstico , Hemangioma Cavernoso del Sistema Nervioso Central/genética , Hemangioma Cavernoso del Sistema Nervioso Central/fisiopatología , Hemangioma Cavernoso del Sistema Nervioso Central/terapia , Humanos , Proteína KRIT1 , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Terapia Molecular Dirigida , Mutación , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Convulsiones/genética , Convulsiones/patologíaRESUMEN
Increased oxidative stress is known to play a role in the pathogenesis of atherosclerosis, and polymorphisms in genes encoding for enzymes involved in modulation of oxidant stress, such as paraoxonases (PONs), provide a potentially powerful approach to study the risk of disease susceptibility. Aim of our study is to investigate the possible association among PONs polymorphisms, clinical and metabolic factors, and atherothrombotic events in an Italian population. We evaluated in 105 subjects, with or without atherosclerotic risk factors, the presence of PON1 L55M, PON1 Q192R, and PON2 S311C genetic variants, as well as lipid profile, the concentration of aminothiols (blood reduced glutathione, plasma total glutathione, homocysteine, cysteine, cysteinyl glycine), and malondialdehyde as markers of lipid peroxidation. Clinical, biochemical, and genetic variables were correlated with a history of atherothrombosis. Previous atherothrombotic events were found in 42 patients (40 %): myocardial infarction in 24, stroke or transient ischemic attack in 18. By multiple logistic regression analysis, hypertension (OR = 5.538; 95 % CI 2.202-13.902, P < 0.001), HDL-cholesterol concentration (OR = 0.947; 95 % CI 0.910-0.985, P = 0.007), and the presence of C allele in PON2 gene (OR = 3.595; 95 % CI 1.247-10.361, P = 0.018) were independently associated with atherothrombotic events. Our study sheds light on the role of PON2 as a possible cofactor in determining the risk of events together with the well-known risk markers HDL-cholesterol and hypertension.
Asunto(s)
Arildialquilfosfatasa/genética , Trombosis/genética , Alelos , Cisteína/sangre , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Glutatión/sangre , Homocisteína/sangre , Humanos , Hipertensión/genética , Ataque Isquémico Transitorio/genética , Peroxidación de Lípido , Lípidos/sangre , Masculino , Malondialdehído/sangre , Persona de Mediana Edad , Infarto del Miocardio/genética , Estrés Oxidativo , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Accidente Cerebrovascular/genéticaRESUMEN
X-linked thrombocytopenia (XLT) is a rare recessive hereditary disorder characterized by isolated thrombocytopenia with small-sized platelets. The XLT locus has been located to chromosome Xp11 by linkage analysis, which is also where the recently cloned Wiskott-Aldrich syndrome (WAS) gene, maps. The relationship between XLT and WAS has long been debated; they might be due to different mutations of the same gene or to mutations in different genes. We now show that mutations in the WAS gene, different from those found in WAS patients, are present in three unrelated male patients with isolated thrombocytopenia and small-sized platelets. Our results demonstrate that XLT and WAS are allelic forms of the same disease, but the causes of the differences need to be further investigated.
Asunto(s)
Alelos , Mutación , Proteínas/genética , Trombocitopenia/genética , Síndrome de Wiskott-Aldrich/genética , Cromosoma X , Secuencia de Bases , Niño , ADN/genética , Cartilla de ADN/genética , Exones , Mutación del Sistema de Lectura , Genes , Humanos , Intrones , Masculino , Datos de Secuencia Molecular , Mutación Puntual , Reacción en Cadena de la Polimerasa , Proteína del Síndrome de Wiskott-AldrichRESUMEN
The past few years have seen rapid advances in our understanding of the genetics and molecular biology of cerebral cavernous malformations (CCM) with the identification of the CCM1, CCM2, and CCM3 genes. Recently, we have recruited a patient with an X/3 balanced translocation that exhibits CCM. By fluorescent in situ hybridization analysis, sequence analysis tools and database mining procedures, we refined the critical region to an interval of 200-kb and identified the interrupted ZPLD1 gene. We detected that the mRNA expression level of ZPLD1 gene is consistently decreased 2.5-fold versus control (P=0.0006) with allelic loss of gene expression suggesting that this protein may be part of the complex signaling pathway implicated in CCM formation.
Asunto(s)
Cromosomas Humanos Par 3 , Hemangioma Cavernoso del Sistema Nervioso Central/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Transducción de Señal/fisiología , Translocación Genética , Adulto , Línea Celular , Rotura Cromosómica , Bases de Datos de Proteínas , Femenino , Hemangioma Cavernoso del Sistema Nervioso Central/metabolismo , Hemangioma Cavernoso del Sistema Nervioso Central/patología , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/fisiología , Imagen por Resonancia Magnética , Fenotipo , Insuficiencia Ovárica Primaria/complicaciones , Insuficiencia Ovárica Primaria/genética , ARN Mensajero/metabolismo , Inactivación del Cromosoma X/genéticaRESUMEN
We report on the genetic and molecular characterisation of an Italian family with a late-onset, autosomal dominant transthyretin amyloidosis. The transthyretin gene was analysed by polymerase chain reaction (PCR), restriction generating PCR, and sequencing, allowing us to discover in one allele a novel point mutation. It consists of a G to C transversion at position 1692 of the genomic sequence, leading to a Thr for Arg substitution at the position 34 of the polypeptidic chain. This mutation is associated with a severe sensory-motor peripheral neuropathy and a restrictive cardiomyopathy.
Asunto(s)
Amiloidosis/genética , Mutación Puntual/genética , Prealbúmina/genética , Anciano , Análisis Mutacional de ADN , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Linaje , Reacción en Cadena de la Polimerasa/métodos , Treonina/genéticaRESUMEN
An increase in the number of (CAG)n repeats in the first coding exon of the androgen receptor (AR) gene has been strongly associated with Kennedy disease (KD) (spinal and bulbar muscular atrophy). This is an X-linked hereditary disorder characterized by motoneuron degeneration occurring in adults together with gynecomastia and hyperestrogenemia. We have performed AR gene molecular analysis in several members of a large family with KD as well as in 25 sporadic patients suffering from heterogeneous motoneuron disease (MND). An increase in the length of the (CAG)n repeats was detected, as expected, in all the affected males and in obligatory carrier females, some of which had minor signs of lower motoneuron involvement. There was only one possible exception, one young male with initial signs of the disease, who had an apparent normal length allele. An increased pathological allele was also found in 3 patients with MND. This indicates that the analysis of (CAG)n repeats of the AR gene plays a role in the differential diagnosis of this heterogeneous group of neurological diseases.
Asunto(s)
Enfermedad de la Neurona Motora/diagnóstico , Enfermedad de la Neurona Motora/genética , Atrofia Muscular Espinal/diagnóstico , Atrofia Muscular Espinal/genética , Receptores Androgénicos/genética , Secuencias Repetitivas de Ácidos Nucleicos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Diagnóstico Diferencial , Femenino , Ligamiento Genético , Ginecomastia/genética , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Linaje , Cromosoma X/genéticaRESUMEN
We report the clinical, neurophysiological, neuropsychological, neuropathological and molecular findings in a large family with X-linked bulbar and spinal muscular atrophy (X-BSMA). Molecular study, performed in 28 family members, showed an increase in the number of CAG repeats in 6 affected males (including 2 presymptomatic patients), and in 10 females, of whom 5 were obligate carriers. All symptomatic patients showed, besides the typical manifestation of X-BSMA, neurophysiological signs of sensory nerve involvement, and abnormal findings in neuropsychological tests. Sural nerve biopsy, performed in two patients, was consistent with axonal atrophy and slow-rate degeneration, with secondary demyelination. Neurophysiological alterations were also present in 6 out of 8 carriers, consisting of neurogenic EMG changes in 3 cases and abnormal sensory action potentials (SAP) and reduced conduction velocity of the sural nerve in 3 cases. Abnormalities of at last two neuropsychological tests were found in 6 out of 8 carriers. Alterations of the sensory nerves in X-BSMA patients have been previously reported in some cases; however, we demonstrate for the first time sensory nerve involvement also in carriers. Evidence of central nervous system involvement, with neuropsychological impairment in all symptomatic patients and in some carriers, is another feature of this family, not previously reported in X-BSMA. In spite of the variable phenotypic features, the number of CAG repeats ranged from 40 to 44 in the affected patients, indicating that phenotypic expression was not related to the size of the mutation, but was probably age-related.
Asunto(s)
Ligamiento Genético , Enfermedad de la Neurona Motora/genética , Atrofia Muscular/genética , Cromosoma X , Adolescente , Adulto , Anciano , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de la Neurona Motora/patología , Atrofia Muscular/patología , Linaje , Receptores Androgénicos/genéticaRESUMEN
The role of folate supplementation in reducing hyperhomocystinemia in patients on dialysis has been reported, but the optimal dose of folate is still unknown. The aim of the present study was to investigate whether greater than 5 mg/day folate supplementation provides any additional effect on plasma homocysteine (HCY) levels. The study was prospective, open, and had no control group. Of the 64 eligible nondiabetic patients on peritoneal dialysis with hyperhomocystinemia (>20 micromol/L), 56 were given oral folate (5 mg/day) for 3 months. When Hcy did not fall below 20 micromol/L, folate doses were increased by 5 mg every 3 months to up to 15 mg/day. With 5 mg/day supplementation, serum folate concentrations increased above the upper confidence limit in 23 patients and erythrocyte folate concentrations in 27 patients. Hcy levels decreased to less than 15 micromol/L in 6 cases and by more than 50% in 12 cases. Nineteen of the remaining patients were given 10 mg/day folate. After increasing the dose, serum and erythrocyte folate levels rose above the upper detection limit. In one patient, plasma Hcy concentrations decreased to less than 15 micromol/L. Ten patients were given 15 mg/day oral folate for an additional 3 months with no effect on homocystinemia. This study confirms that oral folate supplementation may improve hyperhomocystinemia even in patients on dialysis with normal serum or erythrocyte folate concentrations. In fact, serum and erythrocyte levels cannot predict the effect of supplementation on plasma Hcy levels. However, 5 mg/day folate supplementation normalized Hcy in 10% of cases and reduced Hcy levels in another 21%. Increasing the folate dose to greater than 5 mg/day had a minimal (10 mg/day) or no (15 mg/day) additional effect on Hcy concentrations. Despite the minimal effect of increasing folate doses, given the low cost, the absence of side effects, and the high cardiovascular risk for patients on peritoneal dialysis, a careful attempt to increase the dose of oral folate up to 10 mg/day might be suggested.
Asunto(s)
Ácido Fólico/administración & dosificación , Hematínicos/administración & dosificación , Homocisteína/sangre , Hiperhomocisteinemia/tratamiento farmacológico , Fallo Renal Crónico/sangre , Diálisis Peritoneal , Administración Oral , Anciano , Femenino , Ácido Fólico/sangre , Hematínicos/sangre , Humanos , Hiperhomocisteinemia/sangre , Hiperhomocisteinemia/genética , Fallo Renal Crónico/terapia , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Persona de Mediana EdadRESUMEN
PURPOSE: To assess the role of genetic polymorphisms in venous thrombosis events (VTE) using Artificial Neural Networks (ANNs), a model for solving non-linear problems frequently associated with complex biological systems, due to interactions between biological, genetic and environmental factors. METHODS: A database was generated from a case-control study of venous thrombosis, using 238 patients and 211 controls. The database of 64 variables included age, gender and a panel of 62 genetic variants. Three different ANNs were compared, with logistic regression for the accuracy of predicting cases and controls. RESULTS: ANNs yielded a better performance than the logistic regression algorithm. Indeed, through ANNs models, the 62 variables related to genetic variants were first reduced to a set of 9, and then of 3 (MTHFR 677 C/T, FV arg506gln, ICAM1 gly214arg). CONCLUSIONS: The findings of this study illustrate the power of ANN in evaluating multifactorial data, and show that the different sensitivities of the models of elaboration are related to the characteristics of the data. This may contribute to a better understanding of the role played by genetic polymorphisms in VTE, and help to define, if possible, a test panel of genetic variants to estimate an individual's probability of developing the disease.
Asunto(s)
Genes/genética , Predisposición Genética a la Enfermedad , Redes Neurales de la Computación , Polimorfismo Genético , Trombosis de la Vena/genética , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Simulación por Computador , Bases de Datos Factuales , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Trombosis de la Vena/epidemiologíaRESUMEN
Idiopathic recurrent acute pericarditis (IRAP) is suspected to be an autoimmune phenomenon. We studied 46 consecutive patients. We looked for: 1) the occurrence of new diagnoses of autoimmune diseases during our follow up; 2) HLA typing; and 3) the presence of the most frequent mutations linked to familial Mediterranean fever (FMF gene or MEFV). HLA typing was done in 21 patients at loci B, DRB1, DQA1 and DQB1. MEFV gene was looked in 23 patients using specific primers. During the follow-up we made a new diagnosis of primary Sjögren's syndrome in four patients (8.7%) and of rheumatoid arthritis in one patient (2.2%). HLA B14, DRB1*01 and DQB1*0202 were significantly more prevalent, but we did not find a typical HLA typing. MEFV gene was searched: exon 10 was checked by sequence and the E148Q mutation by restriction site analysis. No mutations were found. In conclusion, the prevalence of definite immunorheumatological diseases and the absence of the mutations linked to FMF reinforce the notion that idiopathic acute recurrent pericarditis is an autoimmune condition.
Asunto(s)
Fiebre Mediterránea Familiar/genética , Mutación , Pericarditis/genética , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/genética , Artritis Reumatoide/inmunología , Enfermedades Autoinmunes/genética , Evolución Biológica , Análisis Mutacional de ADN , Fiebre Mediterránea Familiar/complicaciones , Fiebre Mediterránea Familiar/diagnóstico , Fiebre Mediterránea Familiar/inmunología , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Antígenos HLA/genética , Humanos , Italia , Masculino , Pericarditis/etiología , Pericarditis/inmunología , Síndrome de Sjögren/diagnóstico , Síndrome de Sjögren/genética , Síndrome de Sjögren/inmunologíaRESUMEN
A cosmid library was constructed from a YAC clone (XY311) carrying an insert of 650 kb from the F IX/mcf-2 region on human X chromosome. A contig of 200 kb that includes the mcf-2 gene and the genomic region downstream was assembled. Eighty kb of this contig represents a chromosome fragment already cloned and analyzed in detail with conventional restriction enzymes: comparison with this published map suggests that this region was correctly maintained during the procedure of YAC cloning. A discrepancy between the published map and the cloned YAC material was identified, but it resulted to be an EcoRI polymorphism present in the X3000.11 from which the YAC library was derived. The 3' portion of this contig, representing the telomeric end of the YAC XY311, provides new cosmid material for further analysis of the region downstream of the mcf 2 locus.
Asunto(s)
Cromosomas Fúngicos , Genoma Humano , Cromosoma X , Clonación Molecular , Dermatoglifia del ADN , Desoxirribonucleasa EcoRI , Factor IX/genética , Biblioteca de Genes , Humanos , Hibridación de Ácido Nucleico , Polimorfismo de Longitud del Fragmento de Restricción , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo RestrictivoRESUMEN
Transthyretin-related hereditary (TTR) amyloidoses represent a clinically heterogeneous group of diseases associated with various point mutations of the TTR gene. We propose a molecular strategy for the diagnosis of this group of disorders.
Asunto(s)
Amiloidosis/diagnóstico , Amiloidosis/genética , Prealbúmina/genética , Secuencia de Bases , Clonación Molecular , Humanos , Datos de Secuencia Molecular , Mutación , Sondas de Oligonucleótidos/genética , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
In Kennedy disease (an X-linked motoneuronal disorder associated with an increase in the number of (CAG)n triplet repeats in the first exon of the Androgen receptor gene; about twice as many as in normal conditions), polymerase chain reaction-amplified genic products exhibit two DNA fragments in the heterozygous female carriers, one with a range between 468 and 495 bp in the normal polymorphic population and a fragment corresponding to the pathological state that reaches 573 bp. These fragments are easily separated by gel-slab electrophoresis and detected by intercalating dye staining (ethidium bromide). As an alternative procedure, capillary zone electrophoresis in polymer networks, consisting of 8% polyacryloylaminoethoxyethanol at 0% cross-linker, offers a simple procedure for separation and on-line detection via UV absorbance at 254 nm, thus avoiding additional staining steps. The capillary column can be repeatedly used for up to 80-100 times and the electropherogram is stored on a magnetic support. Easy comparison among different runs is obtained by aligning all tracings to an internal standard of a 650 bp fragment added as a marker.
Asunto(s)
Resinas Acrílicas , Electroforesis en Gel de Poliacrilamida/métodos , Atrofia Muscular Espinal/genética , Femenino , Código Genético , Humanos , Masculino , Atrofia Muscular Espinal/diagnóstico , Reacción en Cadena de la Polimerasa , Receptores Androgénicos/genética , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
Affected members and asymptomatic relatives of 9 Italian families with transthyretin (TTR)-related hereditary amyloidosis carrying different TTR mutations (Met30, Pro36, Ala47, Ala49, Gln89) were followed up with repeated EMG investigations. In 3 patients, spontaneous myoclonic discharges with synkinesia were found in the facial muscles. EMG signs of chronic denervation with features of proximal neural involvement were also found in proximal limb muscles. Neuropathy worsened step-wise with progressing clinical stage. Sympathetic skin responses progressively decreased, disappearing in the late stages of the disease. Symptomatic relatives carrying the TTR mutations had significantly reduced sensory conduction velocities and amplitudes of compound motor action potentials. Follow-up studies in 3 patients after liver transplant showed progression of sensory-motor neuropathy 1 year after the transplant, and a slight improvement 18 months later. Based on our electrophysiological findings and a review of the literature, we propose that TTR-related FAP type I be considered not only a peripheral neuropathy, but also a meningoradiculopathy due to deposition of amyloidogenic TTR in the leptomeninges.
Asunto(s)
Neuropatías Amiloides/fisiopatología , Prealbúmina/metabolismo , Piel/fisiopatología , Nervio Sural/fisiopatología , Adulto , Electromiografía , Femenino , Humanos , Trasplante de Hígado , MasculinoRESUMEN
A new type of agarose polyacrylamide mixed-bed gel, obtained by simultaneous gelation of a novel type of allyl-activated agarose and its copolymerization with acrylamide, has pore sizes intermediate between those of polyacrylamide and agarose. The process used to activate the agarose chains enables the substitution to be controlled. As indicated by nuclear magnetic resonance (NMR), only one allyl group was inserted per agarose basic unit. Several formulations of mixed-bed gels, containing different percentages of acrylamide, were compared with conventional polyacrylamide or agarose gels. Resolution, migration distance and band sharpness of different molecular mass fragments were evaluated, with two types of gel run side-by-side in a vertical or horizontal system. The faster electrophoretic mobility of DNA in dilute mix-bed gels and the improved separation of the component of high molecular mass (1 to 6 kbp) of the 1 kbp ladder indicate that these matrices have larger porosity than any dilute polyacrylamide formulations. Sodium dodecyl sulfate (SDS)-protein complexes migrate in the mixed gels faster than in polyacrylamide gels of the same %T.
Asunto(s)
ADN/análisis , Electroforesis/métodos , Proteínas/análisis , Biopolímeros , Secuencia de Carbohidratos , Electroforesis en Gel de Agar/métodos , Electroforesis en Gel de Poliacrilamida/métodos , Datos de Secuencia Molecular , Estructura Molecular , SefarosaRESUMEN
Vascular dementia is usually sporadic and associated with definite risk factors. Several cases also occur in a familial fashion, and may affect middle-aged or even younger subjects. Recently, an autosomal dominant inheritance was demonstrated in two unrelated French families, the members of which were affected by stroke-like episodes culminating in progressive dementia. Genetic linkage analysis assigned the disease locus to chromosome 19q12. We report an additional kindred of Italian origin in which at least 16 subjects presented leukoencephalopathic alterations. Recurrent strokes, psychiatric disturbances, dementia, and in 2 members, tetraplegia and pseudobulbar palsy were the hallmarks of this syndrome. Notably, 5 asymptomatic individuals had neuroradiological signs of leukoencephalopathy. Pathological examination of 1 subject revealed a widespread vasculopathy of the perforating arterioles, characterized by deposition of eosinophilic-congophilic material that did not immunostain with antibodies against prion protein, beta-amyloid, cystatin C, transthyretin, or heat-shock protein 70 and was similar to that described in the French families. Based on the maximum lod score, the most likely location for the disease locus was also mapped to chromosome 19q12, and found to coincide with the CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) locus. The present results confirm the existence of a nosologically distinct, autosomal dominant cerebrovascular disease, presenting with recurrent subcortical ischemic strokes independent of vascular risk factors.
Asunto(s)
Trastornos Cerebrovasculares/genética , Esclerosis Cerebral Difusa de Schilder/genética , Adulto , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/genética , Infarto Cerebral/patología , Trastornos Cerebrovasculares/diagnóstico por imagen , Trastornos Cerebrovasculares/patología , Esclerosis Cerebral Difusa de Schilder/diagnóstico por imagen , Esclerosis Cerebral Difusa de Schilder/patología , Femenino , Ligamiento Genético , Marcadores Genéticos , Humanos , Italia , Masculino , Persona de Mediana Edad , Linaje , Radiografía , SíndromeRESUMEN
Testicular cancer can impair spermatogenesis. In addition, chemotherapy or radiotherapy used for its treatment further damage testicular function mainly affecting highly proliferating germ cells. The multifaceted etiology of male infertility includes, among others, alterations of male reproductive tract differentiation such as monolateral or bilateral congenital absence of vas deferens and perturbations in adrenal steroid synthesis on a genetic basis such as 21beta-hydroxylase deficiency. Herein, we report the case of a male patient with primary infertility, probably related to a combination of genetic and acquired factors with different expressions over time.
Asunto(s)
Hiperplasia Suprarrenal Congénita/diagnóstico , Carcinoma in Situ/diagnóstico , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Oligospermia/complicaciones , Neoplasias Testiculares/diagnóstico , 17-alfa-Hidroxiprogesterona/sangre , Hiperplasia Suprarrenal Congénita/complicaciones , Adulto , Carcinoma in Situ/complicaciones , Carcinoma in Situ/radioterapia , Sulfato de Deshidroepiandrosterona/sangre , Dexametasona , Hormona Folículo Estimulante/sangre , Glucocorticoides , Humanos , Masculino , Mutación , Obesidad/complicaciones , Esteroide 21-Hidroxilasa/genética , Neoplasias Testiculares/complicaciones , Neoplasias Testiculares/radioterapia , Testosterona/sangre , Conducto Deferente/patologíaRESUMEN
We have determined the exon-intron organization of the human X-linked gene (FLN1) encoding actin-binding protein 280 (filamin), a ubiquitous protein that plays an important role in the mechanochemical activities of cells through its association with actin filaments and membrane components. The gene is composed of 47 exons spanning approximately 26 kb. The first and part of the second exon are untranslated. The actin-binding domain at the N-terminus is encoded by exons 2 to 5. The 96-amino-acid repeats corresponding to the elongated rod backbone of the protein are encoded by the remaining 42 exons: size, location, and boundaries of the exons cannot be easily correlated with the repeated structure, while sequences interrupting the repeats (the two hinge segments preceding repeats 16 and 24 and the 8-amino-acid (aa) segment interrupting the 15th repeat) were encoded by separate exons, suggesting that they may be recent additions to the X-linked protein. The 8-aa segment is encoded by exon 29, which is alternatively spliced.
Asunto(s)
Proteínas Contráctiles/genética , Proteínas de Microfilamentos/genética , Cromosoma X , Secuencia de Aminoácidos , Secuencia de Bases , Proteínas Contráctiles/química , Exones , Filaminas , Genes , Humanos , Intrones , Proteínas de Microfilamentos/química , Datos de Secuencia Molecular , Estructura Terciaria de Proteína , Empalme del ARN , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
The region between DXS52 and Factor VIII gene in the human Xq28 chromosomal band contains a G+C-rich isochore to which many genes have been mapped. We report here the isolation and characterization of a transcript mapping about 50 kb telomeric from the vasopressin type 2 receptor gene in a 180-kb YACs/cosmid contig containing the L1CAM gene at its centromeric end. The determined transcribed sequence from a human fetal brain library is identical to that of the recently identified accessory protein HCFC1 (host cell factor, also called C1) that activates herpes simplex virus VP16 (alpha TIF) transactivator protein for association with the octamer motif-binding protein Oct-1 (Cell 74: 115, 1993). The gene is expressed in a ubiquitous pattern and a larger transcript of approximately 10 kb is present in all the tissues tested, while an alternatively spliced RNA of approximately 8.0 kb is present in muscle and heart tissues. Genomic sequencing allowed us to determine that the sequenced transcript is assembled from 26 exons spread over a relatively small genomic region of approximately 24 kb. This alllowed us to determine that a previously reported cDNA clone arises from the splicing out of an internal portion of exon 8 which does not change the reading frame. All together these results raise the possibility that alternative mRNA processing could partly contribute to the diversity of the polypeptide HCFC1 family in a subset of tissues.
Asunto(s)
Proteínas/genética , Factores de Transcripción , Cromosoma X , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Artificiales de Levadura , Factor C1 de la Célula Huésped , Humanos , Datos de Secuencia Molecular , Biosíntesis de Proteínas , Empalme del ARN , ARN Mensajero/genéticaRESUMEN
Transthyretin gene point mutations cause hereditary amyloidosis with an autosomal dominant pattern of inheritance. The disease usually manifests itself in heterozygous patients, although a few homozygotes have been reported. We describe two unrelated patients carrying the Leu64 mutation, one of whom presents a homozygous genotype (Family B). Homozygosity was confirmed by sequence analysis, RG-PCR and double one-dimensional electrophoresis of the plasma protein. Although the clinical picture of the homozygous patient of Family B was more severe than that shown by the heterozygous members of Family A, the variability often displayed by FAP patients does not allow any firm conclusion about the role of homozygosity in the seriousness of the disease.