OMIM (Online Mendelian Inheritance in Man)

OMIM is an online catalogue of human genes and genetic disorders.
http://omim.org/
This website is updated daily with the latest research on over 12,000 genes. It is edited and maintained by McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine and was originally made available on the Internet in 1987. Starting in 1995, OMIM was further developed for the World Wide Web by NCBI (ie. the National Center for Biotechnology Information).
Depending on the gene, this site offers the most recent research and a comprehensive collection of information, including a summary of gene/phenotype relationships. Look up your gene to see what comes up!
You can also search this database by typing in a disease of interest.