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Williams Et Al. (william + et_al)
Selected AbstractsMolecular Genetic Study on Angelman Syndrome Patients without a Chromosomal DeletionEPILEPSIA, Issue 2000Shinji Saitoh Purpose: Angelman syndrome (AS) is a ncurobehavioral disorder characterized by severe mental retardation, easily cvoked laughter, ataxic gait, and epilepsy. Epilepsy associated with AS is characterized by early childhood onset gencralized seizures with profound EEG abnormalities. Therefore, AS is a good human model for genetic epilepsy syndromes. Approximately 70% of AS cases are caused by maternal deletions of chromosomc 15q I I-qI3; whereas, 30% are not associated with a chromosomal dcletion. Thcse non-deletion AS patients are caused by paternal uniparental disomy (UPD), imprinting mutation (IM), or loss-or-function mutations of the UBE3A gene, cach of which predisposes different recurrence risk. To elucidate molecular etiology of non-dclction AS patients, we investigated 34 AS patients without a chromosomal deletion. Methods: Thirty sporadic AS patients, and 4 familial AS patients (2 families of 2 sibs) were enrolled to the study. The diagnosis of AS was based on Williams' criteria (Williams et al., Am J Med Genet 1995, 56: 237). Genomic DNA was extracted from peripheral blood by a standard procedure. DNA mcthylation tcst at SNRPN locus and genotyping using 7 highly informative PCR-based polymorphisms within 15q I I - q I3 were carried out to identify UPD and IM. When both UPD and IM were ruled out, the patients were classified :LS non-UPD, non-IM. For thcsc non-UPD, non-1M paticnts, UBE3A mutations were screened by PCR-SSCP analysis using 10 sets ofprimcrs covering all coding exons. Results: Among 30 sporadic patients, I UPD and 3 IM patients were identified, and the remaining 26 patients were classified as non-UPD, non-IM. Among 4 familial patients, 2 sibs from I family were detected as IM, whcrcas 2 sibs from another family were classified as non-UPD, non-IM. No UBE3A mutations were identified within 26 sporadic and 2 familial non-UPD, non-IM patients. Conclusion: Threc molecular classes were identified for noindeletion AS patients. Therefore, the underlying genetic mechanism was dcmonstratcd to be complex for AS patients without a chromosomal deletion. Combination of the DNA methylation test and PCR-based polymorphisms was sufficient to detect UPD and IM patients. Because recurrence risk is low for UPD and high lor IM, systematic molecular investigation including the DNA methylation test and PCR-based polymorphisms should bc donc for non-delction AS paticnts for genetic counscling purpose. A majority of non-deletion patients were classified as noii-UPD, non-1M. Although, approximate 30% of non-UPD, nonIM patients arc rcportcd to have UBE3A mutations, no such mutations were identified in our study. An underlying molecular mechanism was not rcvealcd for this group of patients, and therefore, assessment of recurrence risk was difficult. Further investigation is necessary for noii-UPD, non-1M paticnts. [source] Comments on the papers by Williams et al., Kulldorff, Knorr-Held and Best, and RogersonJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2001Andrew Lawson [source] Understanding race and human variation: Why forensic anthropologists are good at identifying raceAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2009Stephen Ousley Abstract American forensicanthropologists uncritically accepted the biological race concept from classic physical anthropology and applied it to methods of human identification. Why and how the biological race concept might work in forensic anthropology was contemplated by Sauer (Soc Sci Med 34 1992 107,111), who hypothesized that American forensic anthropologists are good at what they do because of a concordance between social race and skeletal morphology in American whites and blacks. However, Sauer also stressed that this concordance did not validate the classic biological race concept of physical anthropology that there are a relatively small number of discrete types of human beings. Results from Howells (Papers of the Peabody Museum of Archaeology and Ethnology 67 1973 1,259; Papers of the Peabody Museum of Archaeology and Ethnology 79 1989 1,189; Papers of the Peabody Museum of Archaeology and Ethnology 82 1995 1,108) and others using craniometric and molecular data show strong geographic patterning of human variation despite overlap in their distributions. However, Williams et al. (Curr Anthropol 46 2005 340,346) concluded that skeletal morphology cannot be used to accurately classify individuals. Williams et al. cited additional support from Lewontin (Evol Biol 6 1972 381,398), who analyzed classic genetic markers. In this study, multivariate analyses of craniometric data support Sauer's hypothesis that there are morphological differences between American whites and blacks. We also confirm significant geographic patterning in human variation but also find differences among groups within continents. As a result, if biological races are defined by uniqueness, then there are a very large number of biological races that can be defined, contradicting the classic biological race concept of physical anthropology. Further, our results show that humans can be accurately classified into geographic origin using craniometrics even though there is overlap among groups. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Evaluation of diagnostic criteria for atopic dermatitis: validity of the criteria of Williams et al. in a hospital-based settingBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2001H. Gu Background Surveys of the prevalence of atopic dermatitis (AD) have been carried out world-wide, but the results vary widely. The differences probably result from the use of different diagnostic criteria. Williams et al. proposed minimum, simplified, diagnostic criteria that require no invasive test and are easy to use. Pilot studies in European countries showed their suitability for implementation both in hospitals and in the community, and their high sensitivity and specificity. Objectives To evaluate the potential practical value of the criteria of Williams et al. in the Chinese population. Methods The criteria of Hanifin and Rajka (gold standard), Williams et al. and Kang and Tian were applied and compared in 111 patients with AD and 121 control subjects with other skin diseases in three out-patient centres in China. Results The criteria of Williams et al. showed a similar diagnostic efficiency to that of the gold standard, with the sensitivity, specificity and , value reaching 95·50%, 97·52% and 0·93, respectively. No significant difference was found between the criteria of Williams et al. and those of Kang and Tian (,2 = 0·69, P > 0·05). ,Onset under the age of 2 years', a criterion of Williams et al. could be used in subjects of any age. Conclusions The diagnostic efficiency of the criteria of Williams et al. was basically similar to those of Hanifin and Rajka and of Kang and Tian in our out-patient settings. However, those of Williams et al. were easier to apply and required no invasive tests. [source] | ||||||||||