RESUMEN
BACKGROUND: Mutations in the genes encoding components of the tumour necrosis factor (TNF)-α-like pathway cause hypohidrotic ectodermal dysplasia (HED). It has been postulated that the TNF receptor-associated factor 6 (TRAF6) is also involved in this pathway. OBJECTIVES: To investigate mutations in the TRAF6 gene in an individual with HED. METHODS: Genetic analysis was performed on TRAF6 in a patient with HED, her parents, her sister and 150 ethnically matched, healthy individuals. RESULTS: In the patient, sequencing analysis of one DNA strand revealed a deletion of eight nucleotides (c.1074-1081delCAATTTG) in the 5' fragment of the last exon of TRAF6, while no deletion was detected in the other DNA strand indicating a heterozygous mutation. No such sequence abnormality was detected in the patient's parents and her sister. CONCLUSION: This is the first report of a heterozygous TRAF6 sequence variant associated with symptoms typical of HED.
Asunto(s)
Displasia Ectodérmica/genética , Eliminación de Secuencia/genética , Factor 6 Asociado a Receptor de TNF/genética , Adolescente , Exones , Femenino , Mutación del Sistema de Lectura , Heterocigoto , HumanosRESUMEN
Oligodontia, sparse hair and deficiency of eccrine sweat glands are the features characteristic for the phenotype of the patients with anhidrotic ectodermal dysplasia (EDA). This syndrome is caused by mutations in the EDA or DL (downless) genes, encoding members of the TNF ligand and TNF receptor families, involved in the communication between the cells during embryonic life. We investigated both the coding and noncoding regions of the EDA and the DL genes in the patients exhibiting clinical symptoms of ectodermal dysplasia. Sequence analysis of the amplified fragments of the EDA gene revealed polymorphisms in introns three, four and five. The polymorphism in intron four was found in about 60% of the patients and was no more frequent than in the normal individuals. The two other polymorphisms were rare. Polymorphisms were also observed in exons 9 and 12 of the DL gene, but they did not alter the sequence of the protein product of the gene. Our results indicate that in order to accelerate screening for the mutations of the EDA gene and reduce the costs, the amplified fragments should not contain intronic sequences. However, in the case of the DL gene, where polymorphic sites are located in exons, restriction analysis with the use of appropriate enzyme should be conducted, but usually sequencing analysis could not be avoided.
Asunto(s)
Displasia Ectodérmica/genética , Proteínas de la Membrana/genética , Polimorfismo Genético/genética , Ectodisplasinas , Receptor Edar , Humanos , Intrones/genética , Mutación/genética , Fenotipo , Receptores de la Ectodisplasina , Receptores del Factor de Necrosis Tumoral , Eliminación de Secuencia/genéticaRESUMEN
To assess the causal attributions for losing perceived by both early and late adolescents, a sample of 150 high school students responded to a questionnaire comprising three categories of activities (sport, academic, and social) in which they had not won or achieved a desired outcome. The obtained attributions for not winning were categorized into four areas: task difficulty, luck, effort, or ability. Adolescent girls indicated significantly more internal attributions and boys more external attributions. Seventh graders' attributions were external and twelfth graders' were internal. No differences emerged as a function of high and low self-esteem. Implications for the structure of achievement tasks are discussed.
