Biomedical subjects

V Alvarez

Publications and source records attributed to V Alvarez.

At least 55 records · Page 3Linked to original sources

PubMed2000

CCR5 (chemokine receptor-5) DNA-polymorphism influences the severity of rheumatoid arthritis.

Chemokines are critical for the inflammatory process in autoimmune diseases such as rheumatoid arthritis (RA). The chemokine receptor-5 (CCR5) mediates chemotaxis by CC-chemokines and is expressed by lymphocytes with the Th1 phenotype and monocyte/macrophages. A 32 bp deletion in the CCR5 (CCR5-delta 32 allele) abolishes receptor expression in homozygotes, while CCR5-delta 32 carriers would express less receptor than wild-type homozygotes. This polymorphism is related to the resistance to HIV-1 infection and progression towards AIDS. We hypothesized that the CCR5-delta 32 allele may modulate the severity of disease in RA. A total of 160 RA-patients (71 and 89 with severe and non-severe phenotypes, respectively) and 500 healthy individuals from the same Caucasian population (Asturias, northern Spain) were genotyped. Carriers of the CCR5-delta 32 allele were at a significantly higher frequency (P = 0.012) in non-severe compared to severe patients (17% vs 4%). Our results suggest that the CCR5-delta 32 polymorphism is a genetic marker related to the severity of RA.

Arthritis, Rheumatoid↗

PubMed2000

Immunohistochemical localisation of rabbit haemorrhagic disease virus VP-60 antigen in early infection of young and adult rabbits.

This study evaluated the time course distribution of rabbit haemorrhagic disease virus (RHDV) structural protein VP60 in tissues from experimentally infected rabbits from three different age groups. Viral VP60 antigen could not be detected in tissue samples from animals under four weeks, and only a few hepatocytes (0.01 to 0.2 per cent) were stained in the 6-week-old animals. A 6-week-old rabbit euthanised at 72 hpi showed VP60-labelling in hepatocytes and macrophages close to areas of inflammation. Viral VP60 antigen was detected as early as 12 hpi in a few hepatocytes (0.03 per cent) from adult animals. Within this age group, the extent of hepatocyte labelling considerably increased at 18 (3.0 per cent), 24 (25.5 per cent), 36 (50 per cent) and 48 (60 per cent) hpi. Extrahepatic viral VP60 antigen was also detected at 36 and 48 hpi in spleen macrophages and lymphocytes from adult rabbits. These findings support the hypothesis that the hepatocyte is the only cell type in the liver able to support RHDV replication almost immediately after viral infection.

Animals↗

PubMed2000

A DNA polymorphism at the alpha2-macroglobulin gene is associated with the severity of rheumatoid arthritis.

OBJECTIVE: To determine if DNA polymorphisms at the alpha2-macroglobulin (alpha2m) and angiotensin converting enzyme (ACE) genes were associated with rheumatoid arthritis (RA). METHODS: A total of 160 patients (71 with early active severe RA, 89 with non-severe RA) were genotyped (polymerase chain reaction) for the alpha2m (5 bp deletion/insertion) and ACE (I/D) polymorphisms. We also genotyped 500 healthy controls from the same Caucasian population (Asturias, Northern Spain). RESULTS: Carriers of the alpha2m deletion allele were at a significantly higher frequency among patients with an early active severe form of the disease, compared to patients with non-severe RA (p = 0.037). The frequency of the alpha2m deletion allele was significantly higher in patients with severe compared to nonsevere RA (p = 0.017). In addition, the frequency of the deletion allele was significantly higher among patients with 5 or more episodes of acute exacerbation of disease activity per year (n = 39) compared to those with none (n = 46) (p = 0.002). Gene and genotype frequencies for the ACE-I/D polymorphism did not differ between those with early active severe and non-severe RA. CONCLUSION: The genetic variation at alpha2m is associated with the severity of RA. Carriers of the alpha2m deletion allele would have increased risk of developing an early active severe form of the disease. Our data suggest that alpha2m could be a valuable target in the treatment of RA.

Arthritis, Rheumatoid↗

PubMed2000

Synergistic effect between apolipoprotein E and angiotensinogen gene polymorphisms in the risk for early myocardial infarction.

BACKGROUND: Several studies based on different populations worldwide have described an association between cardiovascular diseases and genetic variations in the apolipoprotein E (A:POE), angiotensinogen (A:GT), angiotensin receptor type 1 (A:T1R), and angiotensin-converting enzyme (A:CE) genes. In addition, there is growing evidence of an interaction between hypercholesterolemia and the renin-angiotensin system in the risk for hypertension and atherosclerosis. METHODS: To determine whether the DNA polymorphisms in A:POE (epsilon2, epsilon3, and epsilon4 alleles), A:GT (M235T), A:T1R (1166 A:/C:), and ACE (I:/D:) are associated with early onset of myocardial infarction (MI), we genotyped 220 patients and 200 controls <55 years of age. Patients and controls were males from the same homogeneous Caucasian population. Data concerning hypertension, diabetes, and tobacco consumption were recorded. The lipid profiles of patients and controls were also determined. RESULTS: APOE, ACE, AGT, and AT1R allele and genotype frequencies did not differ between patients and controls. None of these polymorphisms was related to the biochemical values in patients or controls. The frequency of individuals who were both APOE epsilon4 allele carriers and AGT-TT homozygotes was significantly higher in patients than in controls (11% vs 3.5%; P: = 0.0037). In patients, the frequency of epsilon4 carriers was significantly higher (P: <0.00001) in those who were AGT-TT (46%) than those who were AGT-MT/MM (14%). Mean cholesterol was significantly higher in AGT-TT + APOE epsilon34/44 patients than in the TM/MM + epsilon34/44 or TT + epsilon23/33 genotypes (P: = 0. 029). CONCLUSIONS: Our data suggest a synergistic effect between the APOE and AGT polymorphisms and early MI. The increased risk could be mediated in part through higher cholesterol concentrations among individuals who are AGT-TT + APOE epsilon4 allele carriers.

Adult↗

PubMed1999

[Remediable glucocorticoid hyperaldosteronism: molecular diagnosis].

BACKGROUND: The first family diagnosed in Spain of glucocorticoid remediable aldosteronism (GRA) is reported. SUBJECTS AND METHODS: We described the phenotype, biochemical values and genetic diagnosis of a GRA pedigree. DNA analysis was performed by using Southern-blot and polymerase chain reaction. RESULTS: We reported a 14-year-old boy who presented with severe hypertension, and strong family history of early-onset hypertension. His suppressed plasmatic renin activity, family history and failure to respond to conventional antihypertensive therapy raised GRA as a potential etiology. The diagnosis was confirmed by genetic testing, in the index case and in one of family members, which demonstrated the chimeric gene duplication, which was a resultant of a crossing-over between the proximal portion of 11 beta-hydroxylase gen, CYP11B1, and the distal portion of aldosterone synthetase gene CYP11B2. Two other family members, who died, suffered hyporeninemic severe hypertension. The cause of death in one of them was hemorrhagic stroke. Amiloride, which blocks sodium transport in the distal nephron, plus hydroclorothiazide was an effective treatment option. CONCLUSIONS: The role of molecular diagnosis techniques is essential for the rapid diagnosis of cases of arterial hypertension secondary to familial glucocorticoid remediable aldosteronism.

Adolescent↗

PubMed1999

[Frequency of the APOE-4 allele in Alzheimer's disease and its variation with age in Asturias (Spain)].

BACKGROUND: Patients with late-onset Alzheimer's disease show a higher frequency of the APOE-4 than controls. The usefulness of the APOE genotyping in the diagnosis of the disease is controversial. Recently, an age dependent prevalence of APOE-4 in Alzheimer's disease has been described, with a maximum frequency for patients with an age at onset between 65 and 80 years. Additionally, the APOE-4 frequency in healthy controls is similar among the different age-groups, including healthy octogenarians. These data suggest that APOE-4 determines when and not who will develop the disease. PATIENTS AND METHODS: The APOE genotype was defined following a previously described PCR-protocol. We analysed 120 patients with clinically defined probable Alzheimer's disease and 250 controls from the same Caucasian population (Austrias, Northern Spain). RESULTS: We found a significantly higher frequency of the APOE-4 in patients, compared to controls (p = 0.00001). The prevalence of this allele was 65% among patients with an age at onset 66-70, falling to 36% and 18% in patients younger than 65 and older than 80 years, respectively. The average age (SD) at onset did not differ between the E-44 (69 years), E-34 (73 years) and E-33 (73 years). APOE-4 frequency was similar between the different age-groups of controls, including healthy octogenarians. CONCLUSIONS: In Asturias, APOE genotyping can not be used for the presimptomatic diagnosis of Alzheimer's disease. However, individuals carrying this allele would have a higher probability of developing the disease at an age between 65 and 80 years if they are predisposed (genetically and/or environmentally) to the disease.

Adult↗

PubMed1999

Association between an alpha(2) macroglobulin DNA polymorphism and late-onset Alzheimer's disease.

An association between a five-base-pair deletion/insertion DNA polymorphism at the alpha(2) macroglobulin gene (A2M) and late-onset Alzheimer's disease (LOAD) has been recently described. We developed a PCR assay to analyze this polymorphism in 190 LOAD patients (older than 65 years) and 400 controls from Spain. Controls were stratified into three groups: <65 years (n = 200), 65 to 80 years (n = 100), and 81 years or older (n = 100). We found a significantly higher frequency of carriers of the D allele in patients older than 81 years compared to controls older than 81 years (p = 0.0012). In addition, the frequency of the D allele was significantly lower in controls older than 81 years compared to controls younger than 65 (p = 0.048). Our work suggests that the D allele confers an age-dependent increased risk to develop late-onset Alzheimer's disease.

Age of Onset↗

PubMed1999

[Circadian rhythms variability of arterial pressure: methodological aspects for the measurement].

BACKGROUND: To study the differences among the methods used for estimating daytime and nighttime ambulatory blood pressure values, and to analyze their determinant factors. SUBJECTS AND METHODS: In 402 individuals mean values of systolic and diastolic blood pressure (SBP and DBP) during 24 h, daytime and nighttime, were calculated by three different methods: a) real-time, following a minidiary; b) long-time, having a nighttime period from 23:00 to 07:00 h, and a daytime one from 08:00 to 22:00 h, and c) short-time, having a nighttime period from midnight to 6:00 h, and a daytime one from 08:00 to 22:00 h. RESULTS: Daytime mean values of SBP and DBP were similar for the three methods. Nighttime mean values of SBP and DBP calculated using the long-time were significantly higher than those calculated with the real-time ((SBP -2.25 [5.3] mmHg, p < 0.05; DBP -1.17 [3.4] mmHg, p < 0.05). No differences were observed for both SBP and DBP with the real-time. The number of sleeping hours was the main determinant of the differences observed between the long-time and the real-time methods. The percentage of subjects with a non-dipping pattern were 17, 26 and 18% for real, long and short time methods, respectively. CONCLUSIONS: Daytime mean BP values are reproducible whatever the method used, but for estimating nighttime mean BP values short-time is the best of the fixed-time methods. Minidiary should be used if more accurate values are necessary or if the subjects sleep habits do not fit into the standard patterns.

Adolescent↗

PubMed1999

Commutability and traceability: their repercussions on analytical bias and inaccuracy.

The commutability of calibrators and accuracy control materials affects the traceable link between patient sample results and standards. We sought to identify the repercussions of commutability on various aspects of laboratory practice (calibration, control of bias and accuracy assessment) and to discover the solutions that can reduce the problems produced by non-commutability with presently available resources. Ten serum constituents, ten comparison procedures and 37 analytical procedures were studied. The information concerning accuracy and bias provided from materials found to be commutable in previous works was challenged with native serum results for each routine and reference method compared, using Passing-Bablok regression and decision limits derived from biological variation. We found that: (1) Use of commutable control materials did not assure reliable information on the bias (systematic component of analytical error) of analytical procedures, and (2) Results from native serum and commutable controls were very highly concordant, indicating that these materials provide a good indication of the inaccuracy (total analytical error) of results. We suggest that the performance of individual laboratories would be better evaluated by occasional use of native sera with values assigned by reference methods in EQAS schemes. Moreover, our findings support the idea that manufacturers should assign values to calibrators using reference methods and native sera to reduce matrix effects and promote traceability.

Calibration↗

PubMed1999

Factors related to quality of ambulatory blood pressure monitoring in a pediatric population.

To assess the factors related to the quality of ambulatory blood pressure monitoring in a pediatric population, we performed 24-h ambulatory blood pressure monitorings on 333 unselected children aged 3 to 18 years using a Spacelabs 90207 monitor. For each individual, the percentages of valid measurements (ratio between valid and total number of measurements, 76.4% +/-15.6%) and of successful measurements (percentage of valid preset measurements, 89.8% +/- 11.5%) were calculated. Two hundred eighty-one (84.1%) monitorings had a successful measurement rate of >80%. Two hundred thirteen (64%) were of excellent quality, as defined by the percentage of successful measurements being higher than or equal to 90%. Age (P < .0001) and 24-h systolic blood pressure (P < .04) were positively and independently associated (in multiple regression analysis) to the percentage of successful measurements, accounting for 8% of the variance. Furthermore, a significant negative correlation between causal pulse pressure and the number of erroneous measurements was observed (r = -0.18, P < .01). This study has shown that in a pediatric population, the quality of the monitoring depends only in part on age and ambulatory systolic blood pressure values when an oscillometric device is used. The results have demonstrated the important role pulse pressure amplitude plays when accounting for the number of erroneous measurements.

Adolescent↗

PubMed1999

Vocal cord dysfunction in a child.

Vocal cord dysfunction (VCD) involves paradoxical adduction of the vocal cord during the respiratory cycle. This usually occurs during inspiration, but can also be seen in expiration. Vocal cord appositioning produces airflow obstruction sufficient to cause wheezing, shortness of breath, chest tightness, and coughing. These symptoms often imitate the respiratory alterations of asthma, thus leading to inappropriate treatment; intubation or tracheotomy may prove necessary. An 11-year-old girl was admitted with intractable dyspnea. She had been diagnosed with atopic asthma, although she failed to respond to an increase in antiasthma medication, including high-dose oral steroids. Flow-volume loops were abnormal, with evidence of variable extrathoracic airway obstruction, manifested as a flat inspiratory loop. No structural abnormalities were seen with either computed tomography (CT) or magnetic resonance imaging (MRI). Fibroscopy revealed paradoxical adduction of the vocal cords during the respiratory cycle, no obstructive disorder being observed. After the diagnosis of VCD, the clinical manifestations resolved with psychiatric treatment. Adduction was not demonstrable at repeat fibroscopy after treatment. VCD may simulate bronchial asthma; it may also be associated with that disorder, thus masking the diagnosis. It should be suspected in patients with recurrent wheezing who fail to respond to usual asthma treatment. An early diagnosis avoids unnecessary aggressive management. Treatment should consist of respiratory and phonatory exercises; psychotherapy may be useful.

Asthma↗

PubMed1999

Multiple endocrine neoplasia type 1 (MEN1): clinical heterogeneity in a large family with a nonsense mutation in the MEN1 gene (Trp471Stop).

OBJECTIVE: Familial multiple endocrine neoplasia type 1 (MEN1) is an hereditary dominant trait characterized by tumours of the parathyroids, anterior pituitary and endocrine pancreatic glands, among others. The MEN1 gene has recently been cloned, and MEN1-mutations have been identified in several families as well as in a number of sporadic cases. The aim of this study was to search for mutations in a large MEN1-family in order to define the clinical heterogeneity among mutation-carriers. We also analysed DNA from several tumour tissues in order to test the 'two hit' model for inactivation of the MEN1 gene. PATIENTS AND METHODS: We searched for mutations in the MEN1-gene in members of a large MEN1-family. A total of 11 affected and 4 healthy at risk individuals were analysed. DNA was obtained and exons 1 to 10 of the MEN1-gene were PCR-amplified and subjected to automated-direct sequencing. In addition, we isolated DNA from parathyroid tumours of two family members, and compared this DNA with that of the normal tissue counterpart to define if the normal copy of the MEN1-gene was deleted. RESULTS: G to A change at nucleotide 7640 (exon 10) that would convert Trp to Stop at codon 471 was found. This mutation was identified in eleven affected individuals, as well as in four healthy (asymptomatic) family members. These patients showed a wide spectrum of clinical symptoms and ages of presentation. Comparison of normal and tumour DNAs showed the loss of the normal (non-mutated) copy of MEN1 gene in the tumour tissue. CONCLUSION: The different ages of disease presentation and the heterogeneity of symptoms among carriers of the Trp471Stop mutation, which would lead to the synthesis of a truncated non-functional protein, suggest that clinical heterogeneity is a characteristic of MEN1 independent of the type of mutation. Finally, the lack of amplification of the normal MEN1-allele on DNA from parathyroid tumours of two family members indicates that MEN1 is a tumour suppressor gene, the second hit that inactivates the normal copy in mutation carriers being a deletion.

Adolescent↗

PubMed1999

Current databases on biological variation: pros, cons and progress.

A database with reliable information to derive definitive analytical quality specifications for a large number of clinical laboratory tests was prepared in this work. This was achieved by comparing and correlating descriptive data and relevant observations with the biological variation information, an approach that had not been used in the previous efforts of this type. The material compiled in the database was obtained from published articles referenced in BIOS, CURRENT CONTENTS, EMBASE and MEDLINE using "biological variation & laboratory medicine" as key words, as well as books and doctoral theses provided by their authors. The database covers 316 quantities and reviews 191 articles, fewer than 10 of which had to be rejected. The within- and between-subject coefficients of variation and the subsequent desirable quality specifications for precision, bias and total error for all the quantities accepted are presented. Sex-related stratification of results was justified for only four quantities and, in these cases, quality specifications were derived from the group with lower within-subject variation. For certain quantities, biological variation in pathological states was higher than in the healthy state. In these cases, quality specifications were derived only from the healthy population (most stringent). Several quantities (particularly hormones) have been treated in very few articles and the results found are highly discrepant. Therefore, professionals in laboratory medicine should be strongly encouraged to study the quantities for which results are discrepant, the 90 quantities described in only one paper and the numerous quantities that have not been the subject of study.

Clinical Laboratory Techniques↗

PubMed1999

N-acetyltransferase-2, glutathione S-transferase M1, alcohol dehydrogenase, and cytochrome P450IIE1 genotypes in alcoholic liver cirrhosis: a case-control study.

BACKGROUND: Only a small percentage of long-term alcoholics develop liver cirrhosis. Genetic and non-genetic factors have been implicated in the risk of developing this disease. Among the genetic factors, case-control studies suggest an association with some polymorphisms at the alcohol dehydrogenase and cytochrome P450IIE1 genes. N-Acetyltransferase-2 metabolizes multiple compounds, transforming some of them to organ-toxic compounds and others into non-toxic molecules. Slow- and rapid-acetylator individuals exist in most human populations, and the mutations responsible for the slow-acetylator genotype have been determined. Slow acetylators, who should be at higher risk of developing breast cancer, and fast acetylators, who have an increased risk of developing colon cancer, can be characterized by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) genotyping. GSTM1 is another detoxifying enzyme for which functional interindividual differences, on the basis of gene polymorphisms, have been described. METHODS: We conducted a case-control study in which 120 alcoholic cirrhotics, 30 long-term non-cirrhotic alcoholics, and 200 healthy controls were genotyped for polymorphisms (RFLPs) at the ADH2, P450IIE1, and NAT2 genes. PCR, followed by restriction enzyme digestion, was performed. The homozygous deletion of the GSTM1 gene was also PCR-analyzed. Genotype frequencies were statistically compared. RESULTS: Frequencies for the ADH2, P450IIE1, and GSTM1 polymorphisms did not differ between patients and controls. Individuals homozygous for the NAT2*5 allele, which is the most frequent slow-acetylator (SA) allele and shows the lowest acetylator activity, were at a significantly decreased frequency among the cirrhotic patients compared with controls (9% versus 16%; P = 0.042). The frequency of this SA genotype was significantly increased (40%) in long-term alcoholics who did not develop cirrhosis (P = 0.0041 compared with controls; P= 0.000017 compared with cirrhotics). CONCLUSIONS: According to our results, NAT2 activity may be a factor that determines the risk of developing alcoholic liver cirrhosis, and slow acetylators would be protected.

Acetylation↗

PubMed1999

The prothrombin 20210A allele and the factor V Leiden are associated with venous thrombosis but not with early coronary artery disease.

This study was performed in order to establish the role of the prothrombin 20210 G/A and factor V Leiden (R506Q) polymorphisms in the susceptibility to develop venous thromboembolism and early coronary artery disease (CAD). These polymorphisms were determined in 82 consecutive patients with venous thromboembolism, 175 male patients with early CAD, and 200 healthy controls from the same Caucasian population (Asturias, Northern Spain). DNA was amplified using polymerase chain reactions and digested with the appropriate restriction enzymes in order to define the prothrombin and factor V genotypes. The prevalence of the heterozygous for the prothrombin A allele was 3.5% in the general population and 15.8% in patients with venous thrombosis (P = 0.0007); the frequency was 4% in patients with early CAD. No sex-related differences in the prevalence of the A allele were observed, and the average age at the first venous thromboembolic event was similar between GG and AG patients. The frequency of carriers of the factor V Leiden polymorphism was 9.75% among patients with venous thromboembolism, compared with 3.5% among controls, and 3.4% in the patients with CAD. Our data showed an association between venous thromboembolism and the AG genotype at the prothrombin 20210 G/A polymorphism. This polymorphism was not related to an increased risk for early CAD in our population of male patients.

Adult↗

PubMed1999

The O blood group protects against venous thromboembolism in individuals with the factor V Leiden but not the prothrombin (factor II G20210A) mutation.

We investigated the influence of the ABO blood group in the observed prevalences of the recently described factor V R506Q and factor II G20210A mutations in a thrombotic population. We determined the ABO blood group in a sample of 178 unselected patients (aged 17-83 years), diagnosed at our center with deep vein thrombosis or pulmonary embolism. The results of this study show a high prevalence of thrombosis in the non-O blood group. In the general population, the prevalence as a fraction of the O blood group was 2.69 (confidence interval 1.90-3.82). Of the factor V R506Q carriers (n = 28), only one had O group blood and 27 of 28 were non-O (24 A, one B and two AB). However, within the group of factor II G20210A carriers (n = 17), seven had O, nine A and one B type blood. The prevalence of the factor V R506Q mutation within the O blood group was 2.4% (one of 42), significantly lower than in the A group (23.3%, 24 of 103; P = 0.002), or in the overall non-O group (19.9%, 27 of 136; P = 0.006). This prevalence was similar to that observed previously in the non-thrombotic population in our area (3.5%; P = 0.9). We analyzed the clotting activity of factor VIII and we found higher levels in the non-O group (1.78+/-0.61 U/ml) than in the O blood group (1.30+/-0.51 U/ ml; P < 0.0001). We speculate that factor Va in individuals with the factor V Leiden mutation could interact with the high levels of factor VIII clotting activity as a necessary cofactor.

ABO Blood-Group System↗

PubMed1999

Angiotensin converting enzyme and endothelial nitric oxide synthase DNA polymorphisms and late onset Alzheimer's disease.

OBJECTIVES: Several lines of evidence suggest that the endothelial constitutive nitric oxide synthase (ecNOS) and angiotensin converting enzyme (ACE) may have a role in Alzheimer's disease. ACE is widely expressed in the brain, and a DNA polymorphism at the ACE gene has been linked to the risk for late onset Alzheimer's disease. Nitric oxide (NO) production by microglial cells, astrocytes, and brain microvessels is enhanced in patients with Alzheimer's disease. There is a growing evidence that NO is involved in neuronal death in Alzheimer's disease, and the oxidative stress caused by NO in the brain could be a pathogenic mechanism in Alzheimer's disease. The objective was to determine if two DNA polymorphisms at the ecNOS and ACE genes that have been linked with different levels of enzyme expression, have some effect on the risk of developing late onset Alzheimer disease. METHODS: A total of 400 healthy controls younger than 65 years and 350 patients with Alzheimer's disease (average age 72 years) were genotyped for the ACE and ecNOS polymorphisms. To define a possible role for these polymorphisms in longevity 117 healthy controls older than 85 years were also analysed. Genomic DNA was obtained and amplified by polymerase chain reaction, and genotypes were defined following a previously described procedure. Gene and genotype frequencies between patients and controls were compared statistically. RESULTS: Gene and genotype frequencies for the ecNOS and ACE polymorphisms did not differ between both groups of healthy controls (<65 years and >85 years). EcNOS gene and genotype frequencies were similar between patients and controls. There was a slight but significantly increased frequency of the ACE-I allele among patients with Alzheimer's disease compared with controls (p=0.03; OR=1.28, 95%CI= 1.04;1.58). CONCLUSIONS: The ACE-I allele was associated with a slightly increased risk of developing late onset Alzheimer's disease.

Age Factors↗

PubMed1999

[Huntington chorea: clniical and molecular analysis in Asturian patients].

UNLABELLED: AIM AND PATIENTS: To analyse 38 patients with Huntington's disease from 27 families. RESULTS: The CAG repeat at the huntingtin gene was expanded between 40 and 72 times. The size in normal chromosomes varied from 12 to 30 repeats. We found a significantly negative correlation between the number of CAG-repeats and the age of clinical manifestations. However, age and clinical characteristics of the first symptoms were highly variable between patients with a similar size of the expanded allele. Patients who inherited the disease from their fathers showed a higher number of repeats than those who received the disease from their mothers. However, in one case of father to son transmission we observed a reduction of the number of CAG repeats. CONCLUSIONS: These data make it difficult to use the molecular analysis for the presymptomatic diagnosis of clinical course in individuals carrying the expansion.

Adolescent↗