Online Mendelian Inheritance in Man (OMIM): What it is & What it can do for you Knowledge Management & Eskind Biomedical Library January 27, 2012 helen naylor

Objectives Quick review of Central Dogma ◦ Define terms Familiarize with OMIM: ◦ Gene record ◦ Phenotype record ◦ Additional features ◦ Links to other databases/resources

Central Dogma of Biology… Flow of genetic information DNA RNA Protein DNA RNA Protein translationtranscription Genotype Phenotype Genotype Phenotype

Genes & Genetic concepts… Gene: A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genetics: the study of single genes Genome: all the genetic information of an organism

Gene: ◦ Segment of DNA ◦ Basic unit of heredity ◦ Many genes present on a chromosome ◦ Two copies of each gene Genetics: The study of single genes Genome: all the genetic information of an organism Genes & Genetic concepts

Alleles Allele: One of two or more forms of a gene 2 copies of each gene ◦ One from mom; one from dad ◦ If they are the same, homozygous ◦ If different, heterozygous Hh Hh HH hh Homozygote HH HH Heterozygote

Genotype & Phenotype Genotype ◦ Genetic constitution of an individual ◦ Specific allele make up of an individual Phenotype ◦ Expression of the genotype ◦ Individual's observable traits ◦ Hair color, eye color, height

Alleles, Genotype & Phenotype ◦ Bloodgroups! Parent Alleles ABO A AA (A) AB (AB) AO (A) B AB (AB) BB (B) BO (B) O AO (A) BO (B) OO (O) Genotype Phenotype

Central Dogma of Biology Epigenetics Errors in DNA sequence ◦ SNP (small nucleotide polymorphisms) ◦ CNV (copy number variations) Enzyme issues (missing, mistakes) Splicing issues Protein amino acid substitutions ◦ Incomplete translation ◦ Incorrectly folded protein ◦ Reduced/no function DNA (genotype) RNA Protein (phenotype) DNA (genotype) RNA Protein (phenotype) transcription translation

Alternative Splicing ~30,000 genes  90,000+ proteins A single gene usually contains several exons and introns Exons can be spliced together in different ways. Produce different forms of a protein from the same gene. Resulting mRNAs are called transcript variants.

A catalog of human genes and genetic disorders Curated database containing descriptions of relationship between phenotypes, their genes, and variations including ◦ Small Nucleotide Polymorphisms (SNPs) ◦ Copy number variations (CNVs) Maintained at Johns Hopkins University Updated daily Online Mendelian Inheritance in Man ® (OMIM ® )

OMIM ® Two types of entries: ◦ phenotype entries ◦ gene entries  Selected allelic variants are included in gene entries— Those contributing to a disease, with a high frequency, a distinctive phenotype, or some other clinical significance Each entry is assigned a six digit number, usually preceded by a symbol which indicates the type of record Records contain useful links to various databases including gene, protein and clinical resources Search by gene, disease, primary symptom, drug…

OMIM ® OMIM via NCBI ( Screenshot from NCBI OMIM. Accessed 1/11/ OMIM.org

OMIM ® Homepage:

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