21 research outputs found

    Heterozygous Loss-of-Function Mutations in DLL4 Cause Adams-Oliver Syndrome.

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    Adams-Oliver syndrome (AOS) is a rare developmental disorder characterized by the presence of aplasia cutis congenita (ACC) of the scalp vertex and terminal limb-reduction defects. Cardiovascular anomalies are also frequently observed. Mutations in five genes have been identified as a cause for AOS prior to this report. Mutations in EOGT and DOCK6 cause autosomal-recessive AOS, whereas mutations in ARHGAP31, RBPJ, and NOTCH1 lead to autosomal-dominant AOS. Because RBPJ, NOTCH1, and EOGT are involved in NOTCH signaling, we hypothesized that mutations in other genes involved in this pathway might also be implicated in AOS pathogenesis. Using a candidate-gene-based approach, we prioritized DLL4, a critical NOTCH ligand, due to its essential role in vascular development in the context of cardiovascular features in AOS-affected individuals. Targeted resequencing of the DLL4 gene with a custom enrichment panel in 89 independent families resulted in the identification of seven mutations. A defect in DLL4 was also detected in two families via whole-exome or genome sequencing. In total, nine heterozygous mutations in DLL4 were identified, including two nonsense and seven missense variants, the latter encompassing four mutations that replace or create cysteine residues, which are most likely critical for maintaining structural integrity of the protein. Affected individuals with DLL4 mutations present with variable clinical expression with no emerging genotype-phenotype correlations. Our findings demonstrate that DLL4 mutations are an additional cause of autosomal-dominant AOS or isolated ACC and provide further evidence for a key role of NOTCH signaling in the etiology of this disorder

    The parent?infant dyad and the construction of the subjective self

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    Developmental psychology and psychopathology has in the past been more concerned with the quality of self-representation than with the development of the subjective agency which underpins our experience of feeling, thought and action, a key function of mentalisation. This review begins by contrasting a Cartesian view of pre-wired introspective subjectivity with a constructionist model based on the assumption of an innate contingency detector which orients the infant towards aspects of the social world that react congruently and in a specifically cued informative manner that expresses and facilitates the assimilation of cultural knowledge. Research on the neural mechanisms associated with mentalisation and social influences on its development are reviewed. It is suggested that the infant focuses on the attachment figure as a source of reliable information about the world. The construction of the sense of a subjective self is then an aspect of acquiring knowledge about the world through the caregiver's pedagogical communicative displays which in this context focuses on the child's thoughts and feelings. We argue that a number of possible mechanisms, including complementary activation of attachment and mentalisation, the disruptive effect of maltreatment on parent-child communication, the biobehavioural overlap of cues for learning and cues for attachment, may have a role in ensuring that the quality of relationship with the caregiver influences the development of the child's experience of thoughts and feelings

    Filarial vector studies in a diethylcarbamazine-treated and in untreated villages in Papua New Guinea

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    Entomological studies were undertaken in three villages in the East Sepik Province of Papua New Guinea. The inhabitants of one village, Nanaha, had been treated with diethylcarbamazine (DEC) to reduce the prevalence and density of microfilaraemia of Wuchereria bancrofti. No intervention was undertaken in the other two villages, Yauatong and Musenau, in which bancroftian filariasis was present but with markedly different human prevalence rates and mean parasite densities. In Yauatong, infection rates in anopheline vectors (Anopheles punctulatus and An. koliensis) varied from 20.5 to 46.6% with infectivity rates of 0-1.4% while these rates were 10.9-14.3% and 0-1.1% respectively in Culex quinquefasciatus. In Nanaha after DEC treatment, infection rates were as high as 16.3% in An. koliensis and infectivity rates reached 7.0% for An. punctulatus despite a 45% reduction in the number of people with detectable microfilariae (mf) and a 94% reduction in mf density in those who remained positive
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