Interactive effects of mindfulness and negative urgency on intimate partner aggression perpetration

Intimate partner aggression (IPA) is a costly and incompletely understood phenomenon. Negative urgency, the tendency to act impulsively in response to negative affect, is predictive of IPA perpetration. Mindfulness, by virtue of its emphasis on nonreactivity to negative affect, is an opposing force to urgent tendencies that may mitigate the negative urgency-IPA link. Yet, no research to date investigates the interactive effects of negative urgency and mindfulness on IPA perpetration. Two studies were conducted that measured and manipulated multiple facets of mindfulness alongside measures of negative urgency and tendencies of IPA perpetration (combined N = 508 undergraduate students in monogamous intimate relationships). Counter to our preregistered predictions, we found that negative urgency's association with greater IPA perpetration increased at higher levels of mindfulness. These findings suggest that mindfulness may not be a protective factor against IPA perpetration for individuals higher in negative urgency, but rather may serve as a risk factor.

Quantitative 3D evaluation of step ascent and descent in individuals with Down syndrome--analysis of a daily challenging task

BACKGROUND

Step ascent and descent can perturb stability increasing the incidence of falls, especially in older individuals with functional limitations and intellectual disabilities, such as those with Down syndrome (DS). The aim of this study was to investigate the biomechanics and motor coordination of step ascent and descent in adults with DS and compare them with a group of healthy individuals, considering movement kinematics and kinetics.

METHOD

Fourteen adults with DS and 12 similarly aged adults without DS who were free of known motor problems were quantitatively assessed during ascending and descending a step using an optoelectronic system (BTS SMART-D), force platforms and video recording. Kinematic and kinetic parameters were identified and calculated for each study participant and comparisons were made between the DS and a control group (CG).

RESULTS

Despite similar age ranges, subjects in the DS group performed the step ascent and descent movements slower, with longer duration and with a more accentuated range of motion of the trunk and of the ankle joint than those in the CG. Additionally, the double stance phase on the step was substantially longer in the DS group when represented as a percentage of the entire stepping sequence (ascent, double stance on the step and descent). In terms of kinetics, ground force platform data revealed that the DS subjects showed higher instability in the medio-lateral direction during double support phase than similarly aged CG subjects and cannot be attributed to age-associated changes in stability.

CONCLUSIONS

These findings help to elucidate the complex biomechanical strategy of people with DS during a step ascent and descent movement task and may have a major role in the multidimensional evaluation and tailored management for them.

Alterations in mitochondrial DNA copy number and the activities of electron transport chain complexes and pyruvate dehydrogenase in the frontal cortex from subjects with autism

Autism is a neurodevelopmental disorder associated with social deficits and behavioral abnormalities. Recent evidence suggests that mitochondrial dysfunction and oxidative stress may contribute to the etiology of autism. This is the first study to compare the activities of mitochondrial electron transport chain (ETC) complexes (I-V) and pyruvate dehydrogenase (PDH), as well as mitochondrial DNA (mtDNA) copy number in the frontal cortex tissues from autistic and age-matched control subjects. The activities of complexes I, V and PDH were most affected in autism (n=14) being significantly reduced by 31%, 36% and 35%, respectively. When 99% confidence interval (CI) of control group was taken as a reference range, impaired activities of complexes I, III and V were observed in 43%, 29% and 43% of autistic subjects, respectively. Reduced activities of all five ETC complexes were observed in 14% of autistic cases, and the activities of multiple complexes were decreased in 29% of autistic subjects. These results suggest that defects in complexes I and III (sites of mitochondrial free radical generation) and complex V (adenosine triphosphate synthase) are more prevalent in autism. PDH activity was also reduced in 57% of autistic subjects. The ratios of mtDNA of three mitochondrial genes ND1, ND4 and Cyt B (that encode for subunits of complexes I and III) to nuclear DNA were significantly increased in autism, suggesting a higher mtDNA copy number in autism. Compared with the 95% CI of the control group, 44% of autistic children showed higher copy numbers of all three mitochondrial genes examined. Furthermore, ND4 and Cyt B deletions were observed in 44% and 33% of autistic children, respectively. This study indicates that autism is associated with mitochondrial dysfunction in the brain.

Upregulation of Ras/Raf/ERK1/2 signaling and ERK5 in the brain of autistic subjects

Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. A number of studies have shown that the Ras/Raf/ERK1/2 (extracellular signal-regulated kinase) signaling pathway plays important roles in the genesis of neural progenitors, learning and memory. Ras/Raf/ERK1/2 and ERK5 have also been shown to have death-promoting apoptotic roles in neural cells. Recent studies have shown a possible association between neural cell death and autism. In addition, two recent studies reported that a deletion of a locus on chromosome 16, which included the mitogen-activated protein kinase 3 (MAPK3) gene that encodes ERK1, is associated with autism. Most recently, our laboratory detected that Ras/Raf/ERK1/2 signaling activities were significantly enhanced in the brain of BTBR mice that model autism, as they exhibit many autism-like behaviors. We thus hypothesized that Ras/Raf/ERK1/2 signaling and ERK5 could be abnormally regulated in the brain of autistic subjects. In this study, we show that the expression of Ras protein was significantly elevated in the frontal cortex of autistic subjects. C-Raf phosphorylation was increased in the frontal cortex, while both C-Raf and A-Raf activities were enhanced in the cerebellum of autistic subjects. We also detected that both the protein expression and activities of ERK1/2 were significantly upregulated in the frontal cortex of autistic subjects, but not in the cerebellum. Furthermore, we showed that ERK5 protein expression is upregulated in both frontal cortex and cerebellum of autistic subjects. These results suggest that the upregulation of Ras/Raf/ERK1/2 signaling and ERK5 activities mainly found in the frontal cortex of autistic subjects may be critically involved in the pathogenesis of autism.

Autism severity is associated with child and maternal MAOA genotypes

Autism severity is associated with child and maternal MAOA genotypes. We replicated and extended a previously reported association between autism severity and a functional polymorphism in the monoamine oxidase A (MAOA) promoter region, MAOA-uVNTR, in a sample of 119 males, aged 2-13 years, with autism spectrum disorder from simplex families. We demonstrated that (i) boys with the low activity 3-repeat MAOA allele had more severe sensory behaviors, arousal regulation problems, and aggression, and worse social communication skills than males with the high activity allele; and (ii) problems with aggression, as well as with fears and rituals, were modified by the mothers' genotype. Boys with the 4-repeat high activity allele who had homozygous 4-repeat mothers showed increased severity of these behaviors relative to those born to heterozygous mothers. These findings indicate the importance of considering maternal genotype in examining associations of MAOA and other genes with behavior in male offspring.

Association of aggressive behaviours with psychiatric disorders, age, sex and degree of intellectual disability: a large-scale survey

BACKGROUND

The link between aggression and mental disorders has been the focus of diverse studies in persons with and without intellectual disabilities (ID). Because of discrepancies in the finding of studies in persons with ID to date, and because of differences in research design, instruments used and the population studied, more research is needed. The purpose of this study was to delineate any significant association between certain psychiatric disorders and specific domains of aggressive behaviours in a large sample of persons with ID controlling for sex, age, autism and degree of ID.

METHOD

Data from the present study were obtained from 47% of all persons with ID receiving services from New York State agencies, using the Institute for Basic Research - Modified Overt Aggression Scale (IBR-MOAS between 2006 and 2007). The IBR-MOAS was completed by the chief psychologists of 14 agencies based on information from the participants' files. Demographic information obtained included the psychiatric diagnosis made by the treating psychiatrist as well as information on age, sex and degree of ID. Data from 4069 participants were analysed.

RESULTS

Impulse control disorder and bipolar disorder were strongly associated with all five domains of aggressive behaviour in the IBR-MOAS. Psychotic disorder was highly associated with four domains except for physical aggression against self (PASLF), which was of borderline significance. Anxiety was most associated with PASLF and verbal aggression against self (VASLF); depression with VASLF; obsessive compulsive disorder with physical aggression against objects (PAOBJ); personality disorders with verbal aggression against others (VAOTH), VASLF and PASLF; and autism with physical aggression against others (PAOTH), PAOBJ and PASLF. Mild to moderate ID was associated with VAOTH and VASLF and severe to profound ID with PAOBJ and PASLF. Female sex was most associated with VASLF.

CONCLUSIONS

Impulse control, mood dysregulation and perceived threat appear to underlie most of the aggressive behaviours reported. Psychosis and depression appeared to have been over-diagnosed in persons with mild to moderate ID and under-diagnosed in persons with severe and profound ID. These findings replicate and extend findings from previous studies. The pattern of associations reported can be used as helpful indicators by professionals involved in the treatment of aggressive behaviours in persons with ID.

Individualized higher dose of 70-75 Gy using five-fraction robotic stereotactic radiotherapy for non-small-cell lung cancer: a feasibility study

OBJECTIVE

To determine whether robotic stereotactic radiotherapy of 70-75 Gy delivered in five fractions results in an improved therapeutic ratio, compared with three fractions, in the treatment of peripheral non-small-cell lung cancer (NSCLC), in which case doses of up to 85 Gy in five fractions may be feasible.

MATERIALS AND METHODS

Between December 2006 and May 2010, 20 patients (9 female, 11 male, aged 65 to 88) were treated using the CyberKnife® Robotic Radiosurgery System for NSCLC with doses ranging from 67 Gy to 75 Gy based on location, histopathological type, grade of histopathological differentiation, tumor diameter/volume, and normal tissue constraints, with the doses being delivered in five fractions over 5 to 8 days. Tumor diameters ranged from 1.5 cm to 3.4 cm (median: 2.5 cm). Patients with Stage I to IV NSCLC were treated, and the results and observations were analyzed for clinical characteristics and outcomes including toxicity. All patients, except one who had refused surgery, had co-morbid conditions that precluded a lobectomy.

RESULTS

Twenty patients were followed every three months by positron emission tomography/computed tomography (PET/CT). Mean follow-up was 23 months (range: four to 58 months). Local control was achieved in all treated tumors. Three patients expired, and three developed new regional metastases, none of which was within the planning target volume (PTV). The remainder of the patients demonstrated no evidence of recurrence or continued growth detectable by PET/CT. There was no toxicity above Grade 1.

CONCLUSIONS

It is feasible to treat peripheral NSCLC with individualized maximal tolerable doses ranging from 67 Gy to 75 Gy in five fractions chosen on the basis of location, histopathological type, grade of histopathological differentiation, tumor diameter/volume, and normal tissue constraints.

Application of robotic stereotactic radiotherapy to peripheral stage I non-small cell lung cancer with curative intent

AIMS

To determine the effectiveness of robotic stereotactic radiotherapy with image guidance and real-time respiratory tracking against early stage peripheral lung cancer.

MATERIALS AND METHODS

We treated patients with stage I non-small cell lung cancer (NSCLC) with CyberKnife and analysed their clinical characteristics and outcomes. All patients had co-morbid conditions that precluded lobectomy. The clinical target volume (CTV) included the gross tumour volume (GTV) and a 6mm margin in all directions to account for microscopic extension. The planning target volume (PTV) equalled CTV+2mm in all directions for uncertainty. Tumour motion was tracked using a combination of Synchrony and Xsight Spine tracking methods with the aid of a single gold marker implanted in the centre of the tumour, or using the newer Xsight Lung method without markers for selected tumours. A 60-67.5 Gy dose was prescribed to the 60-80% isodose line (median 65%) and given in three to five fractions. Patients were followed every 3 months for a median of 27.5 months (range 24-53 months).

RESULTS

Of the 67 patients with NSCLC stage IA or IB treated between January 2004 and December 2008, we report the results of a cohort of 31 with peripheral stage I tumours of 0.6-71 cm(3) volume treated between January 2004 and December 2007 with total doses between 60 and 67.5 Gy in three to five fractions. The median D(max) was 88.2 Gy and the median V(95) of the PTV was 99.6% or 27.9 cm(3). No grade 3 or above toxicity was encountered. Four cases of radiation pneumonitis and one case of oesophagitis were observed. In those patients whose pre- and post-treatment results were available, no change in pulmonary function tests was observed. Actuarial local control was 93.2% for 1 year and 85.8% for up to 4.5 years. One-year overall survival was 93.6% and 83.5% for up to 4.5 years, as projected by Kaplan-Meier analyses.

CONCLUSIONS

In this small cohort of patients with stage I peripheral NSCLC, robotic stereotactic radiotherapy seems to be a safe and obviously superior alternative to conventionally fractionated radiotherapy, with results that may be approaching those obtained with lobectomy without the associated morbidity.

Detection of HLA antigens on progeria syndrome fibroblasts

It has been suggested that cultured skin fibroblasts derived from patients with progeria, a premature aging syndrome, have absent or markedly reduced HLA antigen expression, thus implicating a possible immunological role in the pathogenesis of this disease. An analysis of HLA expression in nine progeric fibroblast strains and related familial strains is reported. Normal HLA expression and inheritance were found. No significant association between HLA type and progeria was detected. Therefore, we conclude an abnormality of HLA expression is unlikely to be an underlying defect in progeria.

Association of autism severity with a monoamine oxidase A functional polymorphism

A functional polymorphism (the upstream variable-number tandem repeat region, or uVNTR) in the monoamine oxidase A (MAOA) promoter region has been reported to be associated with behavioral abnormalities as well as increased serotonergic responsivity. We examined the relation between MAOA-uVNTR alleles and the phenotypic expression of autism in 41 males younger than 12.6 years of age. Children with the low-activity MAOA allele had both lower intelligence quotients (IQ) and more severe autistic behavior than children with the high-activity allele. In follow-up testing of 34 of the males at the 1-year time-point, those with the low-activity allele showed a worsening in IQ but no change in the severity of their autistic behavior. We conclude that functional MAOA-uVNTR alleles may act as a genetic modifier of the severity of autism in males.

Molecular diagnosis of and carrier screening for the neuronal ceroid lipofuscinoses

The neuronal ceroid lipofuscinoses (NCLs) are a large group of autosomal recessive lysosomal storage disorders with both enzymatic deficiency and structural protein dysfunction. Three typical forms, the infantile (INCL), late-infantile (LINCL), and juvenile (JNCL), are among the most common childhood-onset neurodegenerative disorders. They result from mutations on genes CLN1, CLN2, and CLN3, respectively. We determined that the mutations 223A --> G and 451C --> T in CLN1, T523-1G --> C, and 636 C --> T in CLN2, and deletion of a 1.02-kb genomic fragment in CLN3 are the five common mutations for NCL. To offer clinical genetic testing for the NCLs, we have developed simple and quick PCR-based molecular tests for detecting INCL-, LINCL-, and JNCL-affected individuals from 180 NCL families (27 INCL, 76 LINCL, and 77 JNCL). The sensitivity of testing to detect NCL patients among clinically suspected individuals was determined to be 78% (21/27) for INCL, 66% (54/76) for LINCL, and 75% (58/77) for JNCL. When molecular screening for carriers was conducted among the normal siblings or parents of the probands, we identified two carriers out of three individuals tested for INCL, 20/56 (35.7%) carriers for LINCL, and 48/106 (45.3%) carriers for JNCL families. In addition, 5% (9/180) of NCL patients revealed genetic heterogeneity and were reclassified. Seven patients previously diagnosed as having JNCL were now found to carry mutations of CLN2 (5/7) or CLN1 (2/7) and 2 with late-infantile onsets were identified as carrying mutations of CLN1. Our data demonstrate the importance of DNA testing to detect accurately both affected individuals and carriers in NCL families.

Fmr1 knockout mouse has a distinctive strain-specific learning impairment

The Fmr1 gene knockout mouse is a model for the human Fragile X mental retardation syndrome. Fmr1 knockout mice with a C57BL/6-129/OlaHsd hybrid background have been reported to have only a very mild deficiency in learning the Morris water maze task. We compared the effect of this knockout mutation on learning in mice with either an FVB/N-129/OlaHsd hybrid background or a C57BL/6 background. When FVB-129 mice were tested in a cross-shaped water maze task, the knockout mice showed a pronounced deficiency in their ability to learn the position of a hidden escape platform in comparison to normal littermates. In contrast, knockout mice with a C57BL/6 background learned the maze just as well as their normal littermates. Fear conditioning did not reveal differences between knockout and normal mice in either background. These results show that silencing the Fmr1 gene clearly interfered with learning a specific visuospatial task in FVB/N-129 hybrid mice but not in C57BL/6 mice. The strain dependence may model the influence of genetic background in the human Fragile X syndrome.

The digital transformation of oral health care. Teledentistry and electronic commerce

BACKGROUND

Health care is being changed dramatically by the marriage of computers and telecommunications. Implications for hospitals and physicians already have received extensive media attention, but comparatively little has been said about the impact of information technology on dentistry. This article illustrates how the digital transformation will likely affect dentists and their patients.

CONCLUSIONS

Based on recent experiences of hospitals and medical practices, dentists can expect to encounter revolutionary changes as a result of the digital transformation. The Internet, the World Wide Web and other developments of the information revolution will redefine patient care, referral relationships, practice management, quality, professional organizations and competition.

PRACTICE IMPLICATIONS

To respond proactively to the digital transformation of oral health care, dentists must become familiar with its technologies and concepts. They must learn what new information technology can do for them and their patients and then develop creative applications that promote the profession and their approaches to care.

Haplotype analysis at the FRAXA locus in Thai subjects

The prevalence of fragile X syndrome (FXS) is approximately 7% in Thai boys with developmental delay of unknown cause. To determine if FXS might have a specific haplotype association, we analyzed 125 unrelated control subjects and 25 unrelated FXS patients using 3 microsatellites, DXS548, FRAXAC1 and FRAXE, and two single nucleotide polymorphisms, ATL1 and IVS10. FRAXAC1 and DXS548 are located approximately 7 kb and approximately 150 kb proximal to the CGG-FMR1 whereas ATL1, IVS10 and FRAXE are located approximately 5.6 kb, approximately 24.5 kb and approximately 600 kb distal to the CGG-FMR1. We found 40 haplotypes in the control group and 14 haplotypes in the FXS group. Of 14 haplotypes in the FXS group, 6 haplotypes were not found in the control group suggesting possible new mutations or admixture of immigrant haplotypes. We observed that most diverse haplotypes came from different FRAXE alleles. For this reason, we analyzed haplotypes composed from the remaining markers alone (DXS548-FRAXAC1-ATL1-IVS10). We found 2 major haplotypes (20-18-G-T and 20-19-A-C) with no significant haplotype differences between the control group (67/125 of 20-18-G-T and 25/125 of 20-19-A-C) and FXS group (16/25 of 20-18-G-T and 6/25 of 20-19-A-C). The other haplotypes found were 33/125 in the control group and 3/25 in the FXS group. The two major haplotypes associated FXS in Thai subjects were the two most common haplotypes in the normal Thai subjects. We could not prove, therefore, that there were founder effects at the FRAXA locus in Thailand. We could not, however, exclude it completely. These findings apparently contrast with most other reports on FXS founder effects in various ethnic groups.

Heterogeneity of late-infantile neuronal ceroid lipofuscinosis

PURPOSE

Late-infantile neuronal ceroid lipofuscinosis (LINCL), an autosomal recessively inherited lysosomal storage disorder characterized by autofluorescent inclusions and rapid progression of neurodegeneration, is due to CLN2 gene mutations. However, CLN2 mutation analysis has failed to identify some clinically diagnosed "late-infantile" NCL cases. This study was conducted to further characterize genetic heterogeneity in families affected by LINCL.

METHODS

DNA mutations in the CLN1, CLN2, and CLN3 genes that underlie INCL (infantile NCL), LINCL, and JNCL (juvenile NCL), respectively, were studied with molecular analyses.

RESULTS

A total of 252 families affected by childhood NCL were studied. Of 109 families clinically diagnosed as having LINCL, 3 were determined to have either INCL or JNCL by identification of mutation(s) in CLN1 or CLN3. Six families diagnosed initially as having JNCL were found to have LINCL based on the finding of mutations in the CLN2 gene. In addition, several novel mutations were identified.

CONCLUSIONS

Clinical and genetic heterogeneity of LINCL was demonstrated in nine LINCL families studied.

RNAs that interact with the fragile X syndrome RNA binding protein FMRP

The Fragile X protein FMRP is an RNA binding protein whose targets are not well known; yet, these RNAs may play an integral role in the disease's etiology. Using a biotinylated-FMRP affinity resin, we isolated RNAs from the parietal cortex of a normal adult that bound FMRP. These RNAs were amplified by differential display (DDRT-PCR) and cloned and their identities determined. Nine candidate RNAs were isolated; five RNAs, including FMR1 mRNA, encoded known proteins. Four others were novel. The specificity of binding was demonstrated for each candidate RNA. The domains required for binding a subset of the RNAs were delineated using FMRP truncation mutant proteins and it was shown that only the KH2 domain was required for binding. Binding occurred independently of homoribopolymer binding to the C-terminal arginine-glycine-rich region (RGG box), suggesting that FMRP may bind multiple RNAs simultaneously.

CLN-encoded proteins do not interact with each other

The lysosomal storage of lipofuscins is the common pathological feature that characterizes the infantile, late-infantile, juvenile (Batten's disease), and Finnish-variant neuronal ceroid lipofuscinosis (INCL, LINCL, JNCL and FNCL), which are due to mutations in the genes CLN1, CLN2, CLN3, and CLN5, respectively. The CLN1 and CLN2 genes encode lysosomal enzymes, but the CLN3 and CLN5 genes encode membrane-spanning proteins. Why deficiencies of lysosomal enzymes and membrane-spanning proteins produce similar clinical phenotypes and pathological changes is still unanswered. We hypothesize that CLN-encoded proteins may comprise a functional pathogenic pathway, in which protein associations may play important roles. To test this hypothesis, we studied protein-protein interactions among the CLN1-, CLN2-, and CLN3-encoded proteins using a yeast two-hybrid system. Our results provided no evidence that CLN-encoded proteins interact with each other. This suggests there may be unidentified components in NCL pathogenesis.

The feasibility of PCR-based diagnosis of Prader-Willi and Angelman syndromes using restriction analysis after bisulfite modification of genomic DNA

We have developed a novel PCR-based method for studying DNA methylation in the proximal region of 15q, using restriction analysis after bisulfite treatment of genomic DNA. This protocol can be used for the diagnosis of Prader-Willi and Angelman syndromes. Unlike the recently reported methylation-specific PCR protocol, our method avoids the use of multiplex amplification, thus overcoming the need to adjust relative primer amounts and the risk of obtaining false-negative results.

FMR1 CGG-repeat instability in single sperm and lymphocytes of fragile-X premutation males

To determine the meiotic instability of the CGG-triplet repeat in the fragile-X gene, FMR1, we examined the size of the repeat in single sperm from four premutation males. The males had CGG-repeat sizes of 68, 75, 78, and 100, as determined in peripheral blood samples. All samples showed a broad range of variations, with expansions more common than contractions. Examination of single lymphocytes indicated that somatic cells were relatively more stable than sperm. Surprisingly, the repeats in sperm from the 75- and 78-repeat males had very different size ranges and distribution patterns despite the similarity of the repeat size and AGG interruption in their somatic cells. These results suggest that cis or trans factors may have a role in male germline repeat instability.

Regional localization of a nonspecific X-linked mental retardation gene (MRX59) to Xp21.2-p22.2

Linkage analysis was performed on a four-generation family with nonspecific mental retardation (MRX59). The five affected males, ranging in age from 2 years to 52 years, have a normal facial appearance and mild to severe mental impairment. Four obligate carriers are physically normal and not retarded. A maximum LOD score of 2.41 at straight theta = 0.00 was observed with the microsatellite markers, DMD45 in Xp21.2, DXS989 in Xp22.1, and DXS207 in Xp22.2. Recombinations were detected within the dystrophin gene (DMD) in one of the affected males and between DXS207 and DXS987 in Xp22.2 in one of the carriers. These recombinants define the proximal and distal boundaries of a candidate gene region. Genetic localization of this familial condition made prenatal diagnosis informative for one of the obligate carriers.

Trinucleotide CGG repeat in the FMR1 gene in Chinese mentally retarded patients

The fragile X syndrome of mental retardation is related to the number of trinucleotide CGG repeats at the 5'-untranslated region of the FMR1 gene located on the X-chromosome. We have studied X-chromosomes from 649 unaffected Chinese subjects and 324 patients with mild mental retardation. All study subjects were unrelated. The CGG repeat number was analysed by electrophoresis of a polymerase chain reaction followed by gel transfer and hybridisation with a 32P-labeled (CCG)5 probe. The DNA samples having detectable CGG expansion were further analysed by Southern blot analysis with probe StB12.3 after restriction digestion by EcoR I and Eag I. For the unaffected Chinese subjects, a different distribution pattern of CGG allele size from Caucasians was observed. It was a bimodal pattern and the CGG repeat number ranged from 19 to 54. The most common CGG repeat allele was 29 compared with 30 in Caucasians. The second mode appeared at 36 repeats. There was mild statistical difference in the repeat patterns between the mentally retarded patients and unaffected subjects, although the essential features were similar. Among the mentally retarded patients, one male had an unmethylated full mutation and one female had a full mutation. The fragile X prevalence was 0.6%, which is lower than two previous studies in Chinese mentally retarded patients utilising cytogenetic analysis. Our results indicate that a large-scale screening program would be worthwhile to determine the prevalence of the fragile X syndrome in the Chinese population.

Late infantile neuronal ceroid lipofuscinosis is due to splicing mutations in the CLN2 gene

Late infantile neuronal ceroid lipofuscinosis, LINCL, is one of the most common pediatric neurodegenerative disorders. It is caused by mutations in the CLN2 gene, which encodes a lysosomal pepstatin-insensitive peptidase (LPIP). We have identified a novel mutation, T523-1G --> A, by molecular analyses of three unrelated LINCL cases. The mutation was found to affect a 3' intronic splicing acceptor site, resulting in an aberrant mRNA with an insertion of 146 bp of intronic sequence. This causes a frame shift, produces a nonfunctional truncated protein, and results in LINCL.

Frequency of the fragile X syndrome in Chinese mentally retarded populations is similar to that in Caucasians

Fragile X syndrome is recognized as the most common inherited cause of mental retardation in western countries. The prevalence of the fragile X syndrome in Asian populations is uncertain. We report a multi-institutional collaborative study of molecular screening for the fragile X syndrome from 1,127 Chinese mentally retarded (MR) individuals. We found that 2.8% of the Chinese MR population screened by DNA analysis had the fragile X full mutation. Our screening indicated that the fragile X syndrome prevalence was very close to that of Caucasian subjects. In addition, we found that 62.5% of fragile X chromosomes had a single haplotype for DXS548-FRAXAC1 (21-18 repeats) which was present in only 9.7% of controls. This unique distribution of microsatellite markers flanking the FMR1 CGG repeats suggests that the fragile X syndrome in Chinese populations, as in the Caucasian, may also be derived from founder chromosomes.

KH domain-containing proteins of yeast: absence of a fragile X gene homologue

The KH domain is a region defined by its homology to the RNA-binding domains of the heterogeneous nuclear ribonucleoprotein K (hnRNPK). There are two such domains in the FMR1 protein which is underexpressed in the fragile X syndrome. We developed a computer method to search the S. cerevisiae protein sequences as they became available for the KH domain of the FMR1 protein. Using our motif and FINDPATTERNS of the Wisconsin Package of GCG, nine proteins were identified in the completed yeast ORF database that contain KH domains. Five proteins have known or predicted functions; four await functional analysis. Using GeneWorks and GeneJockeyII alignments, we found that the yeast protein KH domain showing the most similarity to either FMR1P KH domain was a KH domain in HX/SCP160. Its sequence is 50% identical to the second KH domain of FMR1P. However, SCP160 contains eight conserved and six degenerate KH domains. Further analysis showed that SCP160 is a better match overall to the vertebrate and C. elegans protein Vigilin, which also contains 14 KH domains. The next most similar yeast KH domain was found in YB83, a protein shorter than FMR1P and containing three KH domains, one of which shares 45% identity with the second KH domain in FMR1P. There is no significant overall sequence similarity between this yeast protein and FMR1P. Thus, while several proteins in yeast contain KH domains, no apparent yeast homologue exists for the FMR1 protein of the fragile X gene family.

Possible founder effects for FRAXE alleles

To determine if FRAXE alleles may have haplotype associations with nearby microsatellites, we analyzed 149 unrelated control Caucasian X chromosomes for FRAXE GCC alleles along with five nearby microsatellites. The microsatellites included three that are new; GT25, CA4, and CA5 located approximately 24, approximately 48, and approximately 50 kb proximal to the FRAXE GCC repeat, and two that were identified previously: DXS8091 and DXS1691, located approximately 90 and approximately 5 kb distal. No significant correlations between haplotypes for the proximal microsatellites were found. Significant correlations of FRAXE GCC repeats and distal microsatellite allele sizes, DXS8091 (r = 0.24) and DXS1691 (r = -0.40), were found. One haplotype, 18-19 of DXS8091-DXS1691, was present on 57% of chromosomes with > or =22 FRAXE repeats but present on only 10% with <22 repeats. We conclude that this distal haplotype association likely reflects a FRAXE allele founder effect. The lack of association or founder effects seen for the three newly identified proximal markers, located within 50 kb of FRAXE GCC, may reflect an unusually high rate of mutation for these microsatellites or a higher rate of recombination in the proximal region.

FRAXAC1 and DXS548 polymorphisms in the Chinese population

The fragile X syndrome is the most common inherited form of mental retardation. Haplotype studies using FRAXAC1 and DXS548 polymorphic markers flanking the fragile site have demonstrated linkage disequilibrium at the FMR1 locus. We investigated the association of the FRAXAC1, DXS548 and CGG alleles between normal subjects and mentally retarded (MR) patients of unspecified cause who do have fragile X syndrome. We have evaluated the FRAXAC1 site in 390 normal subjects and 321 MR patients and the DXS548 site in 146 normal and 319 MR subjects. Both FRAXAC1 and DXS548 alleles were determined by application of the polymerase chain reaction. When compared with Caucasians, the normal Chinese population has a different FRAXAC1 allele distribution. There are more AC18 repeat alleles and fewer AC19 repeat alleles. The DXS548 allele distributions were similar between Chinese and Caucasians. The same distribution pattern of FRAXAC1 alleles was found in both normal subjects and MR patients, but there were significant differences in the distribution patterns of DXS548 alleles. The FMR1 CGG-DXS548 and FRAXAC1-DXS548 haplotype distribution between normal subjects and MR patients also differed significantly. Our results suggest a possible association between DXS548 alleles and non-FRAXA mental retardation.

Reduced mRNA for G3BP in fragile X cells: evidence of FMR1 gene regulation

Although fragile X syndrome is caused by the absence of fragile X gene expression, little is known about the pathogenic processes underlying the mental retardation. Recent findings that the fragile X protein, FMRP, contains RNA binding motifs and nuclear transport signals and associates with ribosomes suggest that FMRP may be involved in either mRNA processing, transport, or translation. To test the hypothesis that absence of FMRP may affect the processing of specific transcripts, we have used an RNA differential display assay (RDDA) to identify differentially expressed transcripts in lymphoblast lines derived from fragile X syndrome patients. A 0.9-kb cDNA fragment that showed reduced expression in a fragile X lymphoblast cell line was found to be identical to G3BP (Ras-GTPase-Activating protein SH3-domain-binding protein). Quantitative reverse transcriptase-polymerase chain reaction showed that the expressed levels of G3BP mRNA in fragile X lymphoblast cell lines were significantly less than controls. Our results indicate that G3BP mRNA may be regulated by FMRP and supports the hypothesis that FMRP may modulate the transcription of specific transcripts.

Ultrastructure of the fragile X chromosome: new observations on the fragile site

Using a nonair-drying modification of a method for longitudinal sectioning of metaphase spreads on glass slides [Wen et al., 1997], we have studied 14 preidentified X chromosomes (10 from fragile X specimens and 4 controls) with transmission electron microscopy (TEM). Four of 10 X chromosomes from fragile X specimens exhibited lighter chromatin density in the area of and distal to the fragile site, most pronounced under dark-field TEM. A clear line of separation at the fragile site locus was also observed by TEM in an X chromosome with no visible fragile site after Q-banding. We hypothesize that these areas of lighter density, including lines of separation, precede the appearance of the fragile site that is commonly observed using light microscopy.

Fragile X premutation is a significant risk factor for premature ovarian failure: the International Collaborative POF in Fragile X study--preliminary data

The preliminary results of an international collaborative study examining premature menopause in fragile X carriers are presented. A total of 760 women from fragile X families was surveyed about their fragile X carrier status and their menstrual and reproductive histories. Among the subjects, 395 carried a premutation, 128 carried a full mutation, and 237 were noncarriers. Sixty-three (16%) of the premutation carriers had experienced menopause prior to the age of 40 compared with none of the full mutation carriers and one (0.4%) of the controls. Based on these preliminary data, there is a significant association between fragile X premutation carrier status and premature menopause.

Accelerated prenatal diagnosis of fragile X syndrome by polymerase chain reaction restriction fragment detection

Prenatal diagnosis of fragile X syndrome requires detection of the full FMR1 mutation in chorionic villus or amniotic fluid cell samples. Although analysis of genomic DNA restriction fragment pattern is a highly reliable technique for identification of the full FMR1 mutation, standard Southern blot determination of this pattern requires significantly more genomic DNA than is initially available from a prenatal sample. To overcome this limitation we developed a method that determines the diagnostic pattern of genomic restriction fragments from a fraction of a prenatal specimen. The prenatal DNA sample is first digested with EcoRI and EagI, and after agarose gel electrophoresis, the 2- to 10-kb region of the gel is serially sectioned and amplified by polymerase chain reaction. Analysis of prenatal samples from an unaffected male and from a full mutation male showed that this approach generated a diagnostic pattern comparable with a Southern blot of 100-fold more material. This innovation enables laboratories to prenatally diagnose the full FMR1 mutation sooner than standard techniques.

Prenatal fragile X detection using cytoplasmic and nuclear-specific monoclonal antibodies

We have been carrying out studies aimed at improving prenatal detection of the fragile X chromosome/mutation. Our current protocol requires a turnaround time (TAT) of several days. In an attempt to reduce the TAT, we have turned to the use of monoclonal antibodies (mAbs). Monoclonal antibody 1A1 (provided by Dr. Mandel of INSERM) immunostaining was performed according to a modified three-step immunocytochemical procedure. We found that cytoplasmic staining intensities, using mAb 1A1/avidin biotinylated complex/diaminobenzidine, varied from light to heavy within each sample, with controls exhibiting a majority of heavily stained cells in both chorionic villus (CV) sample and amniotic fluid cultured cells. Using mAb 1A1 and a new nuclear-specific antibody, mAb 3F11, we found that CV cultured cells harboring the FMR1 full mutation could be distinguished from controls as early as 10 weeks of gestation in both male and female specimens. Western blot analysis showed that the antibodies have similar staining patterns but that mAb 3F11 has fewer background/nonspecific bands. Our results demonstrate that it is feasible to detect fragile X full mutations within one day after obtaining cells from CV specimens taken as early as 10 weeks of gestation.

5-HTTLPR variants not associated with autistic spectrum disorders

To determine whether there is an association of polymorphic variants of the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR) and autistic spectrum disorders, we analyzed the 5-HTTLPR genotypes of 72 autistic subjects, 11 fragile X syndrome patients with autistic behavior, 43 normal subjects, and 49 fragile X syndrome non-autistic subjects. The distribution frequency of 5-HTTLPR long allele (L) and the short allele (S) variants showed no differences between subjects. Our findings do not support the hypothesis that polymorphic 5-HTTLPR variants are a susceptibility factor for autistic disorders.

Identical twins discordant for Sotos syndrome

The cause of Sotos syndrome is unknown but it usually occurs sporadically. Recent studies have shown no evidence of uniparental disomy. One set of concordant monozygotic twins has been reported. We have identified the Sotos syndrome in one of two 5-year-old male monozygotic twins. Our finding of discordance in these identical twins suggests that a postconceptual mutation, or epigenetic change and/or an environmental factor may be involved in the cause of Sotos syndrome.

Video-assisted thoracic surgery: the Miami experience

This article describes the techniques for performing a video-assisted thoracic surgery (VATS) lobectomy. Each lobe can be approached from anteriorly, posteriorly, or intralobarly. Each method is described and the advantages of each technique are discussed. The surgical results in 105 cases are presented. The VATS technique has decreased operative trauma and has shortened hospital stay with a concomitant reduction in cost to the patient and health-care provider. These advantages make VATS lobectomy an excellent alternative for excision of well localized peripheral lung cancer.

Examination of factors associated with instability of the FMR1 CGG repeat

We examined premutation-female transmissions and premutation-male transmissions of the FMR1 CGG repeat to carrier offspring, to identify factors associated with instability of the repeat. First we investigated associations between parental and offspring repeat size. Premutation-female repeat size was positively correlated with the risk of having full-mutation offspring, confirming previous reports. Similarly, premutation-male repeat size was positively correlated with the daughter's repeat size. However, increasing paternal repeat size was associated also with both increased risk of contraction and decreased magnitude of the repeat-size change passed to the daughter. We hypothesized that the difference between the female and male transmissions was due simply to selection against full-mutation sperm. To test this hypothesis, we simulated selection against full-mutation eggs, by only examining premutation-female transmissions to their premutation offspring. Among this subset of premutation-female transmissions, associations between maternal and offspring repeat size were similar to those observed in premutation-male transmissions. This suggests that the difference between female and male transmissions may be due to selection against full-mutation sperm. Increasing maternal age was associated with increasing risk of expansion to the full mutation, possibly because of selection for smaller alleles within the offspring's soma over time; a similar effect of increasing paternal age may be due to the same selection process. Last, we have evidence that the reported association between offspring sex and risk of expansion may be due to ascertainment bias. Thus, female and male offspring are equally likely to inherit the full mutation.

Two common mutations in the CLN2 gene underlie late infantile neuronal ceroid lipofuscinosis

Late infantile neuronal ceroid lipofuscinosis (LINCL) is one of the most common pediatric neuronal degenerative disorders. A candidate gene underlying this disease, designated CLN2, was recently cloned and the gene product was characterized as a lysosomal pepstatin-insensitive carboxypeptidase (LPIC). Four mutations were identified in CLN2 from three unrelated LINCL individuals. To investigate further the mutation frequency in LINCL, we screened 16 LINCL probands for these four mutations. The previously reported intronic mutation, T523-1 G-->C. was found in 56% (9/16) of the cases, of which two were homozygous and accounted for 34% (11/32) of LINCL chromosomes. The previously reported nonsense mutation, 636 C-->T leading to R208stop, was found in 31% (5/16) of the cases, including one homozygote and accounted for 19% (6/32) of LINCL chromosomes. Two previously described missense mutations, 1107 T-->C and 1108 G-->A, were not detected in any of these 16 probands. In total, the two observed mutations, T523-1 G-->C and 636 C-->T, accounted for 53% (17/32) of LINCL alleles. Thus, one or both mutations were seen in 11 (69%) cases and no mutation has yet been identified in five. Our finding that these two mutations are common in LINCL cases adds further evidence in support of the idea that dysfunction of LPIC underlies LINCL. Positive molecular testing can now complement clinical diagnosis of LPIC and will allow for pre-natal diagnosis for subsequent pregnancies.

The frequency of fragile X syndrome among selected patients at Songklanagarind Hospital during 1991-1996, studied by cytogenetic and molecular methods

Fragile X syndrome is the most common inherited form of mental disability, world-wide. Main clinical features are cognitive deficit, speech difficulties, delayed development, autism, and particular physical characteristics. The syndrome can be cytogenetically diagnosed by the expression of chromosome X fragile site at band Xq27.3. At molecular level, the cause of the syndrome is defined as an abnormal expansion of CGG trinucleotide repeats in the 5'UTR of the FMR-1 gene as well as hypermethylation at the proximal CpG island. Study of fragile X syndrome at Songklanagarind Hospital during May 1991-June 1996 was herein reported. A total of 287 blood samples of 260 unrelated families were cytogenetically examined by using lymphocyte culture method with 2-4 different treatments. Frequency of positive fragile X cases was found to be 7 in 260 (2.7%). Among relatives of the positive ones, 13 individuals were also positive. Other types of chromosome abnormalities were detected in 13 cases (5%). For molecular study, DNA samples were obtained from 97 cases. Investigation of CGG repeat expansion was performed by PCR method. Abnormal expansion was identified as full mutation (> 200 repeats) and premutation (> 50-200 repeats). The abnormalities were found in 14 individuals of 5 unrelated cases; 6 with full mutation and 8 with premutation. No molecular study on the two cytogenetic positive cases has been performed. In conclusion, a total of 50 individuals with fragile X abnormality has been documented: 18 affected cases and 32 carriers. Investigation of the remaining suspected members in positive families is in progress. The information and experience will lead to prevention of this genetic disease by prenatal diagnosis and elective abortion in Thailand.

Molecular screening of Batten disease: identification of a missense mutation (E295K) in the CLN3 gene

Batten disease, the juvenile form of neuronal ceroid lipofuscinosis, is a prevalent neuron degenerative disorder of childhood. A 1.02-kb genomic deletion in the Batten disease gene CLN3 has been determined to be a common mutation. We developed a PCR method to screen for this deletion and tested 43 Batten disease probands. We found 36% (31/86) of Batten disease chromosomes did not carry the 1.02-kb deletion. Of the three heterozygotes for the 1.02-kb deletion, a novel G-to-A missense mutation at nucleotide 1020 of the CLN3 cDNA sequence was found on two of the non-1.02-kb deletion chromosomes. The missense mutation resulted in a substitution of glutamic acid (E) by lysine (K) at position 295 (E295 K). The E295 K mutation causes a change in predicted local protein conformation. This glutamic acid is a highly conserved acidic amino acid, being present in human, mouse, dog and yeast, which suggests it may play an important role in the function of the Batten disease protein.

Studies of atypical JNCL suggest overlapping with other NCL forms

In the United States, juvenile neuronal ceroid-lipofuscinosis (JNCL) is the most common form of NCL. This study analyzed 191 cases, diagnosed on the basis of age-at-onset, clinical symptomatology, and pathologic findings. Twenty percent (40/191) of these cases from 24/120 families manifested atypical clinical symptomatology and/or pathologic findings (typical revealed fingerprints and atypical revealed mixed inclusions, or only curvilinear or granular profiles) and, therefore, represent variant forms of JNCL. Those patients in the study with typical JNCL were a uniform group of cases, whereas the atypical were heterogenous and were divided into 8 subgroups based on the clinicopathologic findings. Forty-three families were analyzed (27 typical, 16 atypical) for the common 1.02 kb deletion and several pedigrees for novel mutations. In typical JNCL the common 1.02 kb deletion in both alleles (homozygous) were observed in 23/27, and only 1 allele (heterozygous) was exhibited in 4/27 families. In atypical JNCL families, 5/16 were heterozygous for the common 1.02 kb deletion. None of the remaining 11/16 families had the common 1.02 kb deletion in either allele, but in 9/11 cases the palmitoyl-protein thioesterase (PPT) levels were deficient. In cases where the mutation in CLN3 gene has not been identified, several possibilities may exist. The phenotype may be caused by a yet undefined mutation in CLN3 or may be due to overlapping with other forms of NCL.

Compound heterozygous genotype is associated with protracted juvenile neuronal ceroid lipofuscinosis

We present a clinicopathological study and the first molecular genetic analysis of a family with 2 siblings affected by a rare, protracted form of juvenile neuronal ceroid lipofuscinosis (JNCL). Molecular genetic studies showed that both siblings, in addition to being heterozygous for the 1.02-kb CLN3 deletion, a common mutation in JNCL, also had a G-to-A missense mutation at nucleotide 1,020 of the CLN3 cDNA sequence on the non-1.02-kb deletion chromosomes. This point mutation resulted in a substitution of glutamic acid by lysine at position 295 of the CLN3 protein. Thus, a single point mutation at residue 295 of the CLN3 protein in protracted JNCL may underlie the phenotype in this form, which differs from that in classic JNCL.

Epigenetic variation illustrated by DNA methylation patterns of the fragile-X gene FMR1

Genomic methylation patterns of mammals can vary among individuals and are subject to dynamic changes during development. In order to gain a better understanding of this variation, we have analyzed patterns of cytosine methylation within a 200 bp region at the CpG island of the human FMR1 gene from leukocyte DNA. FMR1 is normally methylated during inactivation of the X chromosome in females and it is also methylated and inactivated upon expansion of CGG repeats in fragile-X syndrome. Patterns of methylation (epigenotypes) were determined by the sequencing of bisulfite-treated alleles from normal males and females and alleles from a family of five brothers who are methylation mosaics and are affected to various degrees by the fragile-X syndrome. Our data indicate that: (i) methylation of individual CpG cytosines is strikingly variable in hypermethylated epigenotypes obtained from a single individual, suggesting that maintenance of cytosine methylation is a dynamic process; (ii) methylation of non-CpG cytosines in the region studied may occur but is rare; (iii) mosaicism of methylation in the analyzed fragile-X males is remarkably similar to that found for the active X and inactive X alleles in normal females, suggesting that the methylation mosaicism of some fragile-X males reflects similar on and off states of FMR1 expression that exist in normal females; (iv) hypermethylation is slightly more pronounced on fragile-X alleles than on normal inactive X alleles of females; (v) the general dichotomy of hypo- and hypermethylated alleles persisted over the 5 year period that separated samplings of the fragile-X males; (vi) methylation variability was most pronounced at a consensus binding sequence for the alpha-PAL transcription factor, a sequence that may play a role in regulating expression of FMR1.