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1.
Article in English | MEDLINE | ID: mdl-38610116

ABSTRACT

Incarcerated gravid uterus (IGU) is a rare and serious obstetric complication. IGU is defined as the entrapment of the gravid uterus between the pubic symphysis and the sacral promontory. The incidence of IGU is 1 in 3000-10 000 cases. IGU is associated with significant obstetric complications, including preterm labor, intrauterine fetal death, growth restriction, renal failure, uterine ischemia/rupture and thrombosis. Here, we present the case of a primigravida with urinary retention at 14 weeks. On transabdominal ultrasound at 19+5/7 weeks the cervix was difficult to visualize, and the anterior uterine wall appeared thickened. The bladder was elongated superior to the uterus and the placenta was low-lying. Initially the patient was managed with intermittent self-catheterization, and subsequently indwelling catheterization was required from 22 weeks. At 30 weeks, the patient was transferred to a tertiary center and magnetic resonance imaging (MRI) was preformed due to challenging visualization of the cervix on ultrasound and the patient's continued symptoms of constipation and recurrent urinary infections. The MRI found a retroflexed gravid uterus, with vagina and endocervix displaced anteriorly and compressed by the gravid uterus. The findings were consistent with an incarcerated uterus. The patient subsequently had positive urinary cultures for Pseudomonas and rising creatinine. Given the obstructive uropathy and associated morbidity and mortality, a plan for elective pre-term delivery at 33+6/7 weeks was made. Delivery was by midline laparotomy, normal anatomy was restored after manual evacuation of the fundus from below the sacral promontory, and an uncomplicated lower segment transverse uterine cesarean section was performed.

2.
Article in English | MEDLINE | ID: mdl-29849727

ABSTRACT

Evidence regarding opinions on integrative modalities by patients and physicians is lacking. Methods. A survey study was conducted assessing how integrative modalities were valued among hematology/oncology patients and hematologists and oncologists at a major tertiary medical center. Results. 1008 patients and 55 physicians were surveyed. With the exception of support groups, patients valued nutrition services, exercise therapy, spiritual/religious counseling, supplement/herbal advice, support groups, music therapy, and other complimentary medicine services significantly more than physicians (P ≤ 0.05). Conclusion. With the exception of support groups, patients value integrative modalities more than physicians. Perhaps with increasing education, awareness, and acceptance by providers and traditional institutions, integrative modalities could be equally valued between patients and providers. It is possible that increased availability and utilization of integrative oncology modalities at tertiary hospital sites could improve patient satisfaction, quality of life, and other clinical endpoints.

3.
Psychol Med ; 47(3): 451-459, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27760582

ABSTRACT

BACKGROUND: Sleep problems are associated with increased risk of physical and mental illness. Identifying risk factors is an important method of reducing public health impact. We examined the association between maternal postnatal depression (PND) and offspring adolescent sleep problems. METHOD: The sample was derived from Avon Longitudinal Study of Parents and Children (ALSPAC) participants. A sample with complete data across all variables was used, with four outcome variables. A sensitivity analysis imputing for missing data was conducted (n = 9633). RESULTS: PND was associated with increased risk of sleep problems in offspring at ages 16 and 18 years. The most robust effects were sleep problems at 18 years [adjusted odds ratio (OR) for a 1 s.d. increase in PND, 1.26, 95% confidence interval (CI) 1.15-1.39, p < 0.001] and waking more often (adjusted OR 1.14, 95% CI 1.05-1.25, p = 0.003). This remained after controlling for confounding variables including antenatal depression and early sleep problems in infancy. CONCLUSIONS: PND is associated with adolescent offspring sleep problems. Maternal interventions should consider the child's increased risk. Early sleep screening and interventions could be introduced within this group.


Subject(s)
Depression, Postpartum/epidemiology , Mothers/statistics & numerical data , Sleep Wake Disorders/epidemiology , Adolescent , Female , Humans , Male , United Kingdom/epidemiology
4.
Genet Epidemiol ; 26(4): 294-304, 2004 May.
Article in English | MEDLINE | ID: mdl-15095389

ABSTRACT

A model for the transmission of the CGG repeat sequence associated with the fragile-X dynamic mutation in the FMR1 gene is developed. The model incorporates both haplotype and family effects on the expansion rate of the sequence. The resulting random effects model is fitted to new data, using computer-intensive Markov chain Monte Carlo methods. The results demonstrate both the FRAXAC1-DXS458 haplotype and family effects on the transmission of CGG repeats from mother to offspring.


Subject(s)
Bayes Theorem , Fragile X Syndrome/genetics , Australia , Chi-Square Distribution , Female , Genetic Variation , Genetics, Population , Genotype , Haplotypes , Humans , Male , Mothers , Mutation , Phenotype , United States
5.
Am J Med Genet A ; 122A(1): 13-23, 2003 Sep 15.
Article in English | MEDLINE | ID: mdl-12949966

ABSTRACT

The effect of the fragile X pre-mutation and full mutation categories, and FMRP deficits in these categories, on neurocognitive status, have been assessed in fragile X individuals from 144 extended families, which included fragile X individuals, as well as their non-fragile X relatives. Neuropsychological status was assessed by the Wechsler summary and subtest test scores. A modification of the maximum likelihood estimators for pedigree data that is resistant to outliers was used to analyze the data. The results have demonstrated the effect of large expansions of CGG repeat in the FMR1 (fragile X mental retardation 1) gene (full mutation) in decreasing full scale IQ (FSIQ), as well as several FSIQ-adjusted subtest scores in the performance domain. Moreover, the results have demonstrated significant cognitive deficits in male individuals with pre-mutation. FMRP depletion correlates strongly with neurocognitive status in the full mutation subjects. Evidence for the effect of FMRP in smaller expansions (pre-mutation) in reducing FSIQ, Performance and Verbal scores, as well as subtest scores in males, has also been obtained. The results are also suggestive of factors other than FMRP deficit which may determine some specific cognitive deficits in fragile X pre-mutation carriers. Genetic variance estimated from the models accounts for less than half of the total variance in FSIQ, and it varies widely between individual Wechsler subtests.


Subject(s)
Fragile X Syndrome/genetics , Mental Retardation, X-Linked/genetics , Nerve Tissue Proteins/deficiency , RNA-Binding Proteins , Female , Fragile X Mental Retardation Protein , Humans , Male , Mutation , Nerve Tissue Proteins/genetics , Pedigree
6.
Am J Med Genet A ; 118A(2): 127-34, 2003 Apr 15.
Article in English | MEDLINE | ID: mdl-12655493

ABSTRACT

The effect of deficit of the FMR1-gene product (FMRP) on physical phenotype was investigated using a robust modification of the maximum likelihood estimators for pedigree data. The approach is a powerful method of examining genotype-phenotype relationships because it adjusts for intra-familial variation, and the robust modification allows violation of distributional assumptions in the data to be overcome by objectively down-weighting unusual observations. The data on 19 age- or height-adjusted physical measures including head, trunk and limb measures and height and weight from 110 extended fragile X families (including 185 fragile X males and females and 120 normal relatives) were related to the FMRP levels assessed in peripheral blood lymphocytes. A significant interaction between FMRP and age was also included in the models for some measures. The results have demonstrated a linear effect of progressively reducing levels of FMRP on the values of a majority of physical measures considered in the study. The most evident effect of FMRP deficit in sexes combined was in decreasing body height and limb length, and in increasing head height and the degree of connective tissue involvement (measured by the middle finger extension angle). Heritability estimated from the complex FMRP models showed the highest values for height and limb length, and the lowest for weight, finger extension angle and some facial measures. On the basis of the present data, a possible mechanism by which the FMRP deficit impacts physical phenotype is discussed.


Subject(s)
Anthropometry/methods , Fragile X Syndrome/genetics , Nerve Tissue Proteins/metabolism , RNA-Binding Proteins , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Fragile X Mental Retardation Protein , Fragile X Syndrome/metabolism , Fragile X Syndrome/physiopathology , Humans , Immunohistochemistry , Male , Middle Aged , Models, Biological , Mutation , Nerve Tissue Proteins/genetics , Phenotype
8.
Am J Med Genet ; 107(2): 136-42, 2002 Jan 15.
Article in English | MEDLINE | ID: mdl-11807888

ABSTRACT

Relationships between the fragile X dynamic mutation and palmar and finger epidermal ridge measures were assessed using a robust modification of the maximum likelihood estimators for pedigree data. A total of 34 extended families affected with fragile X syndrome were used. Phenotypic traits included ridge count on the thumb and ridge breadth measured in the second palmar interdigital area bilaterally. Genotypic measures were represented by the number of CGG repeats in the FMR1 gene, the levels of specific FMR1 protein (FMRP), fragile X category defined by the size of the CCG repeat, and methylation status of the gene. The results demonstrated a significant fragile X effect (related to the number of CGG repeats) in the thumb ridge count in males. This effect was more evident in ridge breadth and was found in both sexes. However, the relationship between both phenotypic traits and the level of FMRP was nonsignificant. The study makes a useful contribution to the development of methodologies for the analysis of genotype-phenotype relationships in dynamic mutations, especially in overcoming extensive variability in both the genotype and phenotype, and in approaching the statistical problems related to intergenerational changes in repeat size. The findings support the hypothesis that the fragile X mutation affects limb development during an early fetal period.


Subject(s)
Fragile X Syndrome/genetics , Pedigree , RNA-Binding Proteins , Dermatoglyphics , Female , Fragile X Mental Retardation Protein , Genotype , Humans , Male , Nerve Tissue Proteins/genetics , Phenotype
9.
J Med Genet ; 38(7): 453-6, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11432964

ABSTRACT

FMR1 mRNA levels were determined in peripheral blood leucocytes for 48 fragile X males with methylated, full mutation alleles that are resistant to cleavage by methylation sensitive enzymes. Using quantitative (fluorescence) RT-PCR, we observed that more than half of these males produce FMR1 mRNA, with some mRNA levels approaching those found in normal subjects. In none of the samples analysed was there any evidence of premutation alleles. These results suggest that the assumed relationship between enzyme resistance and FMR1 gene silencing may not be generally valid. Despite the presence of FMR1 mRNA in some subjects, no FMRP production was detected by either immunocytochemistry or western blotting. The low/absent FMRP levels are probably a reflection of a post-trancriptional effect such as a defect in translation.


Subject(s)
Alleles , DNA Methylation , Fragile X Syndrome/genetics , Mutation/genetics , Nerve Tissue Proteins/genetics , Protein Biosynthesis , RNA, Messenger/metabolism , RNA-Binding Proteins , Blotting, Southern , Fragile X Mental Retardation Protein , Fragile X Syndrome/enzymology , Gene Silencing , Humans , Male , Models, Genetic , Nerve Tissue Proteins/analysis , RNA, Messenger/genetics , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , Transcription, Genetic/genetics , Trinucleotide Repeats/genetics
10.
Am J Psychiatry ; 158(7): 1040-51, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11431225

ABSTRACT

OBJECTIVE: Fragile X syndrome is a neurogenetic disorder that is the most common known heritable cause of neurodevelopmental disability. This study examined the neural substrates of working memory in female subjects with fragile X syndrome. Possible correlations among behavioral measures, brain activation, and the FMR1 gene product (FMRP expression), as well as between IQ and behavioral measures, were investigated. METHOD: Functional magnetic resonance imaging was used to examine visuospatial working memory in 10 female subjects with fragile X syndrome and 15 typically developing female subjects (ages 10-23 years). Subjects performed standard 1-back and 2-back visuospatial working memory tasks. Brain activation was examined in four regions of the cortex known to play a critical role in visuospatial working memory. Correlations between behavioral, neuroimaging, and molecular measures were examined. RESULTS: Relative to the comparison group, subjects with fragile X syndrome performed significantly worse on the 2-back task but not on the 1-back task. In a region-of-interest analysis focused on the inferior frontal gyrus, middle frontal gyrus, superior parietal lobule, and supramarginal gyrus, comparison subjects showed significantly increased brain activation between the 1-back and 2-back tasks, but subjects with fragile X syndrome showed no change in activation between the two tasks. Significant correlations were found in comparison subjects between activation in the frontal and parietal regions and the rate of correct responses on the 2-back task, but not on the 1-back task. In subjects with fragile X syndrome, significant correlations were found during the 2-back task between FMRP expression and activation in the right inferior and bilateral middle frontal gyri and the bilateral supramarginal gyri. CONCLUSIONS: Subjects with fragile X syndrome are unable to modulate activation in the prefrontal and parietal cortex in response to an increasing working memory load, and these deficits are related to a lower level of FMRP expression in fragile X syndrome subjects than in normal comparison subjects. The observed correlations between biological markers and brain activation provide new evidence for links between gene expression and cognition.


Subject(s)
Brain/anatomy & histology , Brain/physiology , Fragile X Syndrome/diagnosis , Memory Disorders/diagnosis , Psychomotor Performance/physiology , RNA-Binding Proteins , Visual Perception/physiology , Adolescent , Adult , Brain/metabolism , Brain Chemistry/genetics , Child , Comorbidity , Female , Fragile X Mental Retardation Protein , Fragile X Syndrome/epidemiology , Fragile X Syndrome/genetics , Functional Laterality/physiology , Gene Expression , Humans , Intelligence/classification , Linear Models , Magnetic Resonance Imaging/statistics & numerical data , Memory Disorders/epidemiology , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Neuropsychological Tests/statistics & numerical data , Space Perception/physiology , Wechsler Scales/statistics & numerical data
12.
Neuropsychology ; 15(2): 290-9, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11324870

ABSTRACT

Two studies tested the specificity of the neurocognitive profile of women with fragile X syndrome (FXS). First, women with an FXS full mutation were compared with women with a premutation and women without FXS who grew up in FXS families. Women with FXS had a significantly lower IQ than the other groups, and analyses of subtest profiles showed they had a relative weakness on Arithmetic and strength on Picture Completion. Women with FXS performed worse than the other groups on executive function, spatial ability, and visual memory. Next, women with FXS were compared with women without FXS matched on age and IQ. A similar IQ profile was found, but women with FXS were worse than controls only on executive function. The authors also examined which neurocognitive indices were related to the underlying biology of the disorder. Overall, the results indicated that executive rather than visuospatial deficits were primary in the neurocognitive profile of FXS.


Subject(s)
Chromosome Deletion , Cognition Disorders/diagnosis , Cognition Disorders/etiology , Fragile X Syndrome/complications , Fragile X Syndrome/genetics , Point Mutation/genetics , Adolescent , Adult , Brain/physiopathology , Female , Fragile X Syndrome/physiopathology , Humans , Middle Aged , Perceptual Disorders/diagnosis , Perceptual Disorders/physiopathology , Space Perception/physiology , Visual Perception/physiology , Wechsler Scales
13.
Am J Ment Retard ; 106(1): 16-27, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11246709

ABSTRACT

To test the hypothesis that variability in development in fragile X syndrome is related to FMRP (the protein deficient in this syndrome expression), we studied 53 males between 23 and 98 months of age. For the entire group, which included males with either mosaism, partially methylated full mutation, and fully methylated full mutation, FMRP expression ranged from 1% to 40% and accounted for a small but significant amount of variance in level, but not rate, of total development as well as motor, social, adaptive, cognitive, and language development. For males with a fully methylated full mutation, the association was in the hypothesized direction, but not statistically significant. Findings support the hypothesized relationship between FMRP and individual capabilities but suggest that other factors also play a major role.


Subject(s)
Fragile X Syndrome/genetics , Nerve Tissue Proteins/genetics , RNA-Binding Proteins , Adolescent , Child , Child, Preschool , Follow-Up Studies , Fragile X Mental Retardation Protein , Gene Expression , Humans , Male , Point Mutation/genetics , Prospective Studies
14.
Health Serv Res ; 36(6 Pt 2): 16-31, 2001 Dec.
Article in English | MEDLINE | ID: mdl-16148958

ABSTRACT

OBJECTIVE: To explore trends in the nonelderly uninsured population between 1987 and 1996 and examine whether the broad disparities in medical care utilization and out-of -pocket spending between the privately insured and uninsured populations that existed in 1987 continued over the following decade. DATA SOURCES/STUDY DESIGN: Data are from the 1996 Medical Expenditure Panel Survey and the 1987 National Medical Expenditure Survey. We used survey data to create descriptive tables examining the characteristics of the uninsured population and the use of medical services, total and out-of -pocket expenditures, and the burden of out-of -pocket spending for the uninsured and the privately insured in 1987 and 1996. Tabulations are presented by demographic and socioeconomic characteristics. PRINCIPAL FINDINGS: The composition of the uninsured population changed somewhat between 1987 and 1996, with adults over age 18 and employed persons making up larger proportions of the uninsured in 1996, and the poor and those in fair or poor health making up smaller proportions. There were few changes in utilization of services by the uninsured over this period and no change in mean expenses, but there was an increase in receipt of at least one preventive service (mammograms) and a decline in the proportion of families with high out-of-pocket burden. Disparities in use and expenses that existed between the uninsured and the privately insured in 1987, however, remained in 1996. CONCLUSIONS: Despite the fundamental changes in the health care system that took place between 1987 and 1996, health care utilization and expenses for the uninsured changed very little. The uninsured are still much less likely to use services than are the privately insured, and they pay for a larger proportion of their medical care expenses out of pocket. There was some improvement in the burden of out-of -pocket spending between 1987 and 1996, but a significant number of the uninsured still have high financial burden.


Subject(s)
Health Expenditures/trends , Health Services Accessibility/trends , Health Services Needs and Demand/trends , Health Services/statistics & numerical data , Medically Uninsured/statistics & numerical data , Adolescent , Adult , Child , Child, Preschool , Demography , Female , Financing, Personal/statistics & numerical data , Financing, Personal/trends , Health Care Surveys , Health Expenditures/classification , Health Expenditures/statistics & numerical data , Health Services/economics , Health Services Accessibility/economics , Health Services Needs and Demand/economics , Humans , Infant , Infant, Newborn , Insurance Coverage/statistics & numerical data , Male , Medically Uninsured/classification , Medically Uninsured/ethnology , Middle Aged , Patient Acceptance of Health Care/statistics & numerical data , Socioeconomic Factors , United States
15.
Cogn Neuropsychol ; 18(1): 1-18, 2001 Feb 01.
Article in English | MEDLINE | ID: mdl-20945204

ABSTRACT

The language phenotype in individuals with fragile X syndrome (FXS) and its relation to the molecular genetics of the disorder was investigated. Previous research has focused on describing deviance in conversational speech, and has not yet examined component discourse skills. The ability of women with FXS to use coherence to select endings to humorous and straightforward passages was evaluated, and the relation of this with neuropsychological measures of working memory, executive functions, and molecular measures of the syndrome were also evaluated. Three groups of nonretarded women were examined: (a) 14 women with FXS who carry the full mutation; (b) 25 women who carry the premutation; and (c) 16 women without the fragile X mutation. The results indicated that subjects with the full mutation showed a dramatic deficit in selecting appropriate endings to jokes relative to stories, even though the jokes were identical to the stories except for their endings. The coherence deficit found in the jokes task for women with the full mutation was found to correlate strongly with the X activation ratio, and to a neuropsychological measure of working memory. The full mutation subjects' coherence deficit is discussed in terms of the additional demand to hold information in memory and shift set.

16.
Am J Med Genet ; 94(3): 232-6, 2000 Sep 18.
Article in English | MEDLINE | ID: mdl-10995510

ABSTRACT

Fragile X syndrome normally arises as a consequence of large expansions (n >200) of a (CGG)(n) trinucleotide repeat in the promoter region of the FMR1 gene. The clinical phenotype is thought to result from hypermethylation of the repeat and adjacent upstream elements, with consequent down-regulation of transcription (transcriptional silencing). However, the relationship between repeat expansion and transcription has not been defined in the full mutation range. Using the method of quantitative (fluorescence) reverse transcriptase polymerase chain reaction, we demonstrated previously that FMR1 mRNA levels are substantially elevated in premutation (55 200), FMR1 mRNA levels remain significantly elevated (mean 3.5-fold elevation; P = 6.7 x 10(-3)) relative to normal controls, even for alleles exceeding 300 repeats. This conclusion is independent of any assumption regarding the transcriptional activity of methylated alleles. However, if it were assumed that all methylated alleles were transcriptionally silent, the FMR1 mRNA levels for cells with unmethylated alleles would be even higher (mean 4.5-fold elevation; P = 2.1 x 10(-4)). These observations show that the full-mutation CGG expansion per se is not a strong impediment to transcription and that the apparent up-regulation of the FMR1 locus remains active in at least some cells with full-mutation alleles.


Subject(s)
DNA Methylation , Fragile X Syndrome/genetics , Nerve Tissue Proteins/genetics , RNA, Messenger/biosynthesis , RNA-Binding Proteins , Transcription, Genetic , Trinucleotide Repeat Expansion , Alleles , Fragile X Mental Retardation Protein , Heterozygote , Humans , Male , Mutation , Nerve Tissue Proteins/biosynthesis , Phenotype , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation
17.
Brain Res ; 877(2): 367-70, 2000 Sep 22.
Article in English | MEDLINE | ID: mdl-10986352

ABSTRACT

Fragile X syndrome, the most common known cause of inherited mental retardation, is caused by alterations of the FMR1 gene encoding the FMRP protein. We investigated the relation between FMRP protein levels and functional brain activation during a working memory task. Our study provides the first evidence for a relation between FMR1 gene expression and neural activity during higher-order cognition. More broadly, our findings provide the first demonstration of how gene-brain-behavior investigations can help to bridge the gap between molecular and systems neuroscience.


Subject(s)
Cerebral Cortex/physiopathology , Cognition Disorders/physiopathology , Fragile X Syndrome/physiopathology , Nerve Tissue Proteins/metabolism , RNA-Binding Proteins , Adolescent , Adult , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Child , Cognition Disorders/genetics , Cognition Disorders/pathology , Female , Fragile X Mental Retardation Protein , Fragile X Syndrome/metabolism , Fragile X Syndrome/pathology , Gene Expression Regulation, Developmental/genetics , Humans , Magnetic Resonance Imaging/methods , Memory, Short-Term/physiology , Nerve Tissue Proteins/genetics , Neuropsychological Tests , Psychomotor Performance/physiology
18.
Am J Med Genet ; 91(2): 144-52, 2000 Mar 13.
Article in English | MEDLINE | ID: mdl-10748416

ABSTRACT

Most individuals with the fragile X premutation are clinically unaffected; however, some show clinical manifestations, including learning difficulties, emotional problems, or even mental retardation. The basis of clinical involvement in these individuals is unknown. Premutation alleles are reportedly associated with normal levels of mRNA and protein (FMRP). To examine this issue in more detail, we studied six individuals with a premutation. We are reporting these cases to demonstrate a spectrum of phenotypic involvement which can be seen clinically. These cases include one individual with the premutation who has no evidence of FMR1 gene dysfunction but has mental retardation from other causes. Other cases presented here show varying degrees of FMR1 gene dysfunction as assessed by FMRP and FMR1 mRNA levels and various clinical features of fragile X. In two cases we observed a significant reduction in FMRP expression and an elevated FMR1 mRNA expression level associated with moderate cognitive deficit. Thus, the utilization of FMRP measures can be helpful in understanding for which premutation patients clinical involvement is caused by dysfunction of the FMR1 gene.


Subject(s)
Nerve Tissue Proteins/genetics , RNA-Binding Proteins , Abnormalities, Multiple/diagnosis , Adolescent , Adult , Alleles , Behavioral Symptoms , Child , Child, Preschool , DNA Methylation , Family Health , Fathers , Female , Fragile X Mental Retardation Protein , Fragile X Syndrome/genetics , Heterozygote , Humans , Immunohistochemistry , Male , Mothers , Nerve Tissue Proteins/biosynthesis , Phenotype , RNA, Messenger/metabolism , Trinucleotide Repeats
19.
Am J Hum Genet ; 66(1): 6-15, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10631132

ABSTRACT

Fragile-X syndrome is a trinucleotide-repeat-expansion disorder in which the clinical phenotype is believed to result from transcriptional silencing of the fragile-X mental retardation 1 (FMR1) gene as the number of CGG repeats exceeds approximately 200. For premutation alleles ( approximately 55-200 repeats), no abnormalities in FMR1-gene expression have been described, despite growing evidence of clinical involvement in premutation carriers. To address this (apparent) paradox, we have determined, for 16 carrier males (55-192 repeats), the relative levels of leukocyte FMR1 mRNA, by use of automated fluorescence-detection reverse transcriptase-PCR, and the percent of lymphocytes that are immunoreactive for FMR1 protein (FMRP). For some alleles with>100 repeats, there was a reduction in the number of FMRP-positive cells. Unexpectedly, FMR1 mRNA levels were elevated at least fivefold within this same range. No significant increase in FMR1 mRNA stability was observed in a lymphoblastoid cell line (160 repeats) derived from one of the carrier males, suggesting that the increased message levels are due to an increased rate of transcription. Current results support a mechanism of involvement in premutation carriers, in which reduced translational efficiency is at least partially compensated through increased transcriptional activity. Thus, diminished translational efficiency may be important throughout much of the premutation range, with a mechanistic switch occurring in the full-mutation range as the FMR1 gene is silenced.


Subject(s)
Fragile X Syndrome/metabolism , Heterozygote , Nerve Tissue Proteins/metabolism , RNA, Messenger/analysis , RNA-Binding Proteins , Fragile X Mental Retardation Protein , Fragile X Syndrome/genetics , Humans , Leukocytes/metabolism , Male , Nerve Tissue Proteins/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sex Factors , Trinucleotide Repeat Expansion/genetics
20.
Clin Genet ; 55(5): 346-51, 1999 May.
Article in English | MEDLINE | ID: mdl-10422805

ABSTRACT

Methylation of a premutation was found in a small percentage of blood cells in a male premutation carrier for the FMR1 mutation. To investigate the inter-tissue heterogeneity and possible clinical implications of this finding, fibroblast cells from the subject were also studied. Although the premutation size was found to be the same in leukocytes and fibroblasts, the methylation pattern was different. In cultured fibroblasts, the premutation was completely unmethylated, as is typical of premutations, whereas methylation of the premutation was detected in a small percentage of lymphocytes. However, the change in methylation did not affect the FMR1 protein (FMRP) expression, as immunocytochemical analysis of FMRP performed on cultured skin fibroblasts and a blood smear revealed normal levels of expression in both tissues.


Subject(s)
DNA Methylation , Fragile X Syndrome/genetics , Genetic Carrier Screening , Mutation , Nerve Tissue Proteins/genetics , RNA-Binding Proteins , DNA , Female , Fragile X Mental Retardation Protein , Humans , Immunohistochemistry , Male
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