1. Applications of Biological Network Presented and Created By : Harshit Bhatt

2. Contents Introduction Human Diseases and Genes Network Cellular Structure and Functionality Conclusion Reference

3. Introduction The main aspect of applying network in the medical field was to get the knowledge about the biological genes that are related to a variety of disorders and diseases in human body. With help of network, researchers have tried to develop a relationship among the various diseases and the human genes responsible for that. Mapping this network could help to target certain genes to cure various diseases in once in the human body. Deep research on this network lead researchers to conclude that few genes are common genetic origin of various diseases.

4. The Human Disease and Genes Network This network gives an overview of the relationship between the human disorders and genes responsible for it. The human disease network(HDN) is a complete network of the all known human disorders (phenome) which are related to each other with the common genes that are responsible for their mutation. The disease gene network(DGN) is a complete network of all human genes responsible for diseases and are related to each other if they are associated with a common disorder.

5. Here we have the complete HDN and DGN network with disease and genes class separately distinguishable from each other. In the HDN we could see Deafness as the largest node due to the highest number(41) of genes involved with it whereas Colon Cancer and Breast Cancer with the highest Betweenness centrality due to large common number of genes involved in the cancer related diseases. Whereas in the DGN the genes are clustered in accordance to their relation with the diseases (light green cluster for cancer) and their size in accordance to the number of disorders they are connected to. It was concluded with this network that genes are more likely linked to genes in the same disorder class. Hence local factoring accounts for most diseases.

6. Characterizing the Disease Modules Number of observed physical interactions between the products of genes(proteins) within the same disorder (red arrow) and the distribution of the expected number of interactions for the random control (blue). Distribution of the tissue-homogeneity of a disorder (red). Random control (blue) with the same number of genes chosen randomly is shown for comparison.

7. Cellular Network and its Functional Properties The interaction inside the cellular structure and its functionalities was a major point of research in this study. They proposed that disease related proteins have a high tendency to make hubs as they interact mostly with other proteins in the body as compare to the non-disease genes proteins. The disease genes also choose those proteins which are highly connected(interacting) to the other proteins (hubs) which leads to the quick acquisition of diseases in human body.

8. The results here prove the affinity of the disease genes to the hub proteins and the interaction of genes with others. Fig(a) shows us a tendency of all disease genes to form hubs, where we could see the tendency for disease genes to encode proteins with hubs. Fig(c) shows the same relationship but with only essential disease genes where the tendency is much higher to encode hub proteins. Fig(d) gives the relationship for non-essential disease genes to encode hubs which is much lower. Fig(e) and (f) shows the genes coordination within the cell for essential and non-essential disease genes respectively.

9. Conclusion The final study concluded that there are very few disease genes(22%) that are essential which correspond to majority of the disorders of human body as they interact with majority of other genes in a cell which defines cell functionality. Genes within same disorder class are more related to each other than if the network is randomized.

10. Reference The human disease network Kwang-Il Goh*†‡§, Michael E. Cusick†‡¶, David Valle, Barton Childs, Marc Vidal†‡¶**, and Albert-La´ szlo´ Baraba´ si*†‡** *Center for Complex Network Research and Department of Physics, University of Notre Dame, Notre Dame, IN 46556; †Center for Cancer Systems Biology (CCSB) and ¶Department of Cancer Biology, Dana–Farber Cancer Institute, 44 Binney Street, Boston, MA 02115; ‡Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115; §Department of Physics, Korea University, Seoul 136-713, Korea; and Department of Pediatrics and the McKusick–Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205