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Single Family (single + family)

Distribution by Scientific Domains

Medical Sciences	66%
Life Sciences	22%

Selected Abstracts

Behavioural phenotype in Börjeson-Forssman-Lehmann syndrome

JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2009
C. F. De Winter
Abstract Background Börjeson-Forssman-Lehmann syndrome (BFLs) is an X-linked inherited disorder characterised by unusual facial features, abnormal fat distribution and intellectual disability. As many genetically determined disorders are characterised not only by physical features but also by specific behaviour, we studied whether a specific behavioural phenotype exists in BFLs. Methods We studied in detail the behaviour of four molecularly proven BFLs patients, and reviewed available literature on BFLs specifically for behavioural characteristics. Results Behaviour in persons with BFLs is in general friendly, but can be challenging with externalising and thrill-seeking features. Social skills are good. However, variation among patients is wide. Three patients from a single family showed expressed hypersexual behaviour. This was not present in other patients. Conclusion In BFLs a specific behavioural phenotype exists and in behaviour general is challenging besides a friendly habit. Within single families more problematic behaviour may occur. Further behavioural and molecular analysis of a larger group of patients is warranted to determine whether a genotype-behavioural phenotype correlation exists. [source]

Diagnosis and phenotypic classification of Wilson disease,

LIVER INTERNATIONAL, Issue 3 2003
Peter Ferenci
Wilson disease is an inherited autosomal recessive disorder of hepatic copper metabolism leading to copper accumulation in hepatocytes and in extrahepatic organs such as the brain and the cornea. Originally Wilson disease was described as a neurodegerative disorder associated with cirrhosis of the liver. Later, Wilson disease was observed in children and adolescents presenting with acute or chronic liver disease without any neurologic symptoms. While diagnosis of neurologic Wilson disease is straightforward, it may be quite difficult in non-neurologic cases. Up to now, no single diagnostic test can exclude or confirm Wilson disease with 100% certainty. In 1993, the gene responsible for Wilson disease was cloned and localized on chromosome 13q14.3 (MIM277900) (1, 2). The Wilson disease gene ATP7B encodes a P-type ATPase. More than 200 disease causing mutations of this gene have been described so far (3). Most of these mutations occur in single families, only a few are more frequent (like H1069Q, 3400delC and 2299insC in Caucasian (4,6) or R778L in Japanese (7), Chinese and Korean patients). Studies of phenotype-genotype relations are hampered by the lack of standard diagnostic criteria and phenotypic classifications. To overcome this problem, a working party discussed these problems in depth at the 8th International Meeting on Wilson disease and Menkes disease in Leipzig/Germany (April 16,18, 2001),. After the meeting, a preliminary draft of a consensus report was mailed to all active participants and their comments were incorporated in the final text. [source]

Evolution and phylogenetic relationships of chitin synthases from yeasts and fungi

FEMS YEAST RESEARCH, Issue 4 2002
José Ruiz-Herrera
Abstract Chitin, the structural component that provides rigidity to the cell wall of fungi is the product of chitin synthases (Chs). These enzymes are not restricted to fungi, but are amply distributed in four of the five eukaryotic ,crown kingdoms'. Dendrograms obtained by multiple alignment of Chs revealed that fungal enzymes can be classified into two divisions that branch into at least five classes, independent of fungal divergence. In contrast, oomycetes and animals each possess a single family of Chs. These results suggest that Chs originated as a branch of ,-glycosyl-transferases, once the kingdom Plantae split from the evolutionary line of eukaryotes. The existence of a single class of Chs in animals and Stramenopiles, against the multiple families in fungi, reveals that Chs diversification occurred after fungi departed from these kingdoms, but before separation of fungal groups. Accordingly, each fungal taxon contains members with enzymes belonging to different divisions and classes. Multiple alignment revealed the conservation of specific motifs characteristic of class, division and kingdom, but the strict conservation of only three motifs QXXEY, EDRXL and QXRRW, and seven isolated amino acids in the core region of all Chs. Determination of different structural features in this region of Chs brought to light a noticeable conservation of secondary structure in the proteins. [source]

C1584 in von Willebrand factor is necessary for enhanced proteolysis by ADAMTS13 in vitro

HAEMOPHILIA, Issue 4 2007
S. KEENEY
Summary., The cysteine variant of the amino acid change tyrosine/cysteine 1584 (Y/C1584) in von Willebrand factor (VWF) has previously been shown to cosegregate with increased susceptibility of VWF to proteolysis by ADAMTS13. It is not known whether C1584 itself confers increased proteolysis or is linked to a causative change elsewhere in VWF. To address whether C1584 underlies enhanced susceptibility of VWF to ADAMTS13-mediated proteolysis, a single family comprising two heterozygous Y/C1584 individuals and four homozygous Y/Y1584 individuals was investigated. The essential regions of the VWF gene were sequenced in all six individuals and ADAMTS13-mediated proteolysis of plasma VWF was assessed for each individual. Comparison of the VWF coding sequences for the Y/C1584 individuals with those for the Y/Y1584 individuals revealed that two amino acid variants were unique to the heterozygotes: R484 and C1584. The plasma VWF of the two heterozygotes showed increased susceptibility to proteolysis in vitro compared with that of the four homozygotes. In the present study we demonstrate that R484, in the absence of C1584, does not influence VWF proteolysis. Enhanced proteolysis occurred only in the presence of Cys1584. Thus, Cys1584 is necessary for increased susceptibility of VWF to proteolysis by ADAMTS13. [source]

Behavioural phenotype in Börjeson-Forssman-Lehmann syndrome

Family ownership, corporate governance, and top executive compensation

MANAGERIAL AND DECISION ECONOMICS, Issue 7 2006
Suwina Cheng
In this study we investigate how top management pay is determined in a family firm environment where even listed firms are effectively controlled by a single individual or a single family. Using data from Hong Kong, we find that executive directors' pay is reduced if the directors have substantial stockholdings. Moreover, pay is related to profits but not to stock returns. Our results are consistent with external blockholders and independent non-executive directors persuading firms to base top management compensation on a firm's profitability. Copyright © 2006 John Wiley & Sons, Ltd. [source]

A unified mathematical framework for the measurement of richness and evenness within and among multiple communities

OIKOS, Issue 2 2004
Thomas D. Olszewski
Biodiversity can be divided into two aspects: richness (the number of species or other taxa in a community or sample) and evenness (a measure of the distribution of relative abundances of different taxa in a community or sample). Sample richness is typically evaluated using rarefaction, which normalizes for sample size. Evenness is typically summarized in a single value. It is shown here that Hurlbert's probability of interspecific encounter (,1), a commonly used sample-size independent measure of evenness, equals the slope of the steepest part of the rising limb of a rarefaction curve. This means that rarefaction curves provide information on both aspects of diversity. In addition, regional diversity (gamma) can be broken down into the diversity within local communities (alpha) and differences in taxonomic composition among local communities (beta). Beta richness is expressed by the difference between the composite rarefaction curve of all samples in a region with the collector's curve for the same samples. The differences of the initial slopes of these two curves reflect the beta evenness thanks to the relationship between rarefaction and ,1. This relationship can be further extended to help interpret species-area curves (SAC's). As previous authors have described, rarefaction provides the null hypothesis of passive sampling for SAC's, which can be interpreted as regional collector's curves. This allows evaluation of richness and evenness at local and regional scales using a single family of well-established, mathematically related techniques. [source]

CDKN2A mutations in melanoma families from Uruguay

BRITISH JOURNAL OF DERMATOLOGY, Issue 3 2009
A.L. Borges
Summary Background, Familial melanoma, a cluster of several cases within a single family, accounts for approximately 10% of cases of melanoma. Hereditary melanoma is defined as two or more first-degree relatives having melanoma. A member of a melanoma-prone family has a 35,70-fold increased relative risk of developing a melanoma. Genetic susceptibility is linked to the major susceptibility genes CDKN2A and CDK4, and the minor susceptibility gene MC1R. Objectives, To determine the clinical and genetic characteristics of cutaneous melanoma in melanoma-prone families from Uruguay. Methods, We studied 13 individuals from six melanoma-prone families living in Uruguay. Phenotype, familial and personal history were recorded. Molecular screening of CDKN2A and CDK4 was done by polymerase chain reaction,single strand conformational polymorphism analysis. The MC1R gene was sequenced. Results, Mutations in CDKN2A were detected in five of six families: c.,34G>T, p.G101W and p.E88X. A novel germline mutation p.E88X, associated with hereditary melanoma in two unrelated families, is described. We hypothesize that a founder effect occurred probably in the Mediterranean region. No mutations in CDK4 were detected. Six different MC1R variants, all previously reported, were present in Uruguayan families. Conclusions, The overall rate of deleterious CDKN2A mutations in our familial melanoma pedigrees, even though the sample size is small, was considerably higher (83%) than the often quoted range. [source]

Bronchopulmonary carcinoid in multiple endocrine neoplasia type 1,

CANCER, Issue 3 2005
Nirupa Sachithanandan M.B.B.S.
Abstract BACKGROUND Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal-dominant syndrome associated with neoplasia of pituitary, pancreas, parathyroid, and foregut lineage neuroendocrine tissue. Although enteropancreatic carcinoid has been well described in patients with MEN 1, it was believed that bronchopulmonary carcinoid was relatively uncommon, occurring in approximately 5% of patients. It is unclear whether the increased screening of asymptomatic patients with MEN 1 will facilitate early diagnosis of this tumor and improve patient prognosis. METHODS The authors reviewed the patient records and, when available, thoracic computed tomographic (CT) images of 129 MEN 1-affected adult members of a single family to determine the prevalence and prognosis of bronchopulmonary nodules and carcinoid. RESULTS Among 129 patients, a diagnosis of bronchopulmonary carcinoid was noted in the records for 6 individuals (1 male and 5 females; 5%). Thoracic CT scans also were available for review from 32 of those patients. Twelve patients (38%) had pulmonary nodules evident on CT scans. Only hypergastrinemia was significantly more common in patients with pulmonary nodules; otherwise, the spectrum of neoplasia was similar between individuals with and without pulmonary lesions. Histologic diagnoses were available in four patients (three female) with abnormal CT images, and carcinoid was confirmed in each patient. No deaths or distant metastases occurred among the patients despite long-term follow-up (mean, 127 months). CONCLUSIONS The findings suggested that bronchopulmonary carcinoid is more prevalent in patients with MEN 1 than was recognized previously. Furthermore, the diagnosis did not appear to portend a poor prognosis in the majority of affected patients. Cancer 2005. © 2004 American Cancer Society. [source]