Human intellectual disability genes form conserved functional modules in Drosophila

Contains fulltext : 124936.pdf (publisher's version ) (Open Access)Intellectual Disability (ID) disorders, defined by an IQ below 70, are genetically and phenotypically highly heterogeneous. Identification of common molecular pathways underlying these disorders is crucial for understanding the molecular basis of cognition and for the development of therapeutic intervention strategies. To systematically establish their functional connectivity, we used transgenic RNAi to target 270 ID gene orthologs in the Drosophila eye. Assessment of neuronal function in behavioral and electrophysiological assays and multiparametric morphological analysis identified phenotypes associated with knockdown of 180 ID gene orthologs. Most of these genotype-phenotype associations were novel. For example, we uncovered 16 genes that are required for basal neurotransmission and have not previously been implicated in this process in any system or organism. ID gene orthologs with morphological eye phenotypes, in contrast to genes without phenotypes, are relatively highly expressed in the human nervous system and are enriched for neuronal functions, suggesting that eye phenotyping can distinguish different classes of ID genes. Indeed, grouping genes by Drosophila phenotype uncovered 26 connected functional modules. Novel links between ID genes successfully predicted that MYCN, PIGV and UPF3B regulate synapse development. Drosophila phenotype groups show, in addition to ID, significant phenotypic similarity also in humans, indicating that functional modules are conserved. The combined data indicate that ID disorders, despite their extreme genetic diversity, are caused by disruption of a limited number of highly connected functional modules

Scientific understanding and clinical management of Dupuytren disease

Dupuytren disease (DD) is a fibroproliferative disorder of unknown etiology that often results in shortening and thickening of the palmar fascia, leading to permanent and irreversible flexion contracture of the digits. This Review provides a detailed update of the scientific understanding of DD and its clinical management, with perspectives on emerging research and therapy. Established risk factors include genetic predisposition and ethnicity, as well as sex and age. Several environmental risk factors (some considered controversial) include smoking, alcohol intake, trauma, diabetes, epilepsy and use of anticonvulsant drugs, and exposure to vibration. DD has been variously attributed to the presence of oxygen free radicals, trauma to the palmar fascia, or aberrant immune responses with altered antigen presentation, or to interactions between these proposed mechanisms. The presence of immune cells and related phenomena in DD-affected tissue suggests that DD is possibly immune-related. Mechanically, digital contracture is caused by myofibroblasts in the DD palmar fascia; however, the exact origin of this cell type remains unknown. The mainstay of treatment is surgical release or excision of the affected palmodigital tissue, but symptoms often recur. Nonsurgical correction of DD contractures can be achieved by Clostridium histolyticum collagenase injection, although the long-term safety and recurrence rate of this procedure requires further assessment