Online Mendelian Inheritance in Man facts for kids
Imagine a giant online library for human genes! That's pretty much what Online Mendelian Inheritance in Man (OMIM) is. It's a special database that keeps track of all the known human genes.
OMIM lists genes that can cause genetic disorders, and also genes that just give us different traits (like eye color or hair type). It has thousands of entries for genes and even more for phenotypes. A phenotype is basically a feature or characteristic you have because of your genes, like having curly hair or being tall.
When scientists study diseases, OMIM helps them connect diseases to specific genes. This makes it a very useful tool for further research. OMIM is part of the U.S. National Center for Biotechnology Information (NCBI), and people can search it using the NCBI website.
How OMIM Started
The idea for Mendelian Inheritance in Man began as a series of books in the early 1960s. The 12th edition is the most recent book version. The online version, OMIM, became available in 1987. The NCBI then put it on the World Wide Web in 1995, making it much easier for people to access. By 2004, OMIM had more than 15,000 records, and it continues to grow!
Understanding MIM Codes
Every disease and gene in OMIM is given a special six-digit number, called a MIM code. The first digit of this number tells you how the gene or trait is usually inherited, meaning how it's passed down from parents to children.
For example:
- If the first digit is 1, the trait is autosomal dominant. This means you only need one copy of the gene from one parent to show the trait.
- If the first digit is 2, the trait is autosomal recessive. This means you need two copies of the gene (one from each parent) to show the trait.
- If the first digit is 3, the trait is X-linked. This means the gene is located on the X chromosome.
Each trait in OMIM has a MIM number. Sometimes, an asterisk (*) is next to the number, which means we know exactly how the trait is inherited. If you see a number symbol (#) before an entry number, it means that the phenotype (the feature you see) can be caused by a mutation (a change) in two or more different genes. For example, Pelizaeus-Merzbacher disease [MIM #312080] is an X-linked recessive disorder.
MIM Code Ranges and Inheritance
The MIM codes are grouped into ranges, and each range tells you more about how the genes or traits are inherited:
- 100000–299999: These are for autosomal loci (gene locations) or phenotypes that were added before May 15, 1994. Autosomal means they are on chromosomes other than the sex chromosomes (X and Y).
- 300000–399999: These codes are for X-linked loci or phenotypes.
- 400000–499999: These are for Y-linked loci or phenotypes, meaning they are on the Y chromosome.
- 500000–599999: These codes are for genes or traits found in the Mitochondria (the "powerhouses" of our cells).
- 600000–above: These are for autosomal loci or phenotypes that were added after May 15, 1994.
These codes are used by doctors and scientists around the world to create a clear way to identify and study genetic diseases.
See also
In Spanish: Herencia Mendeliana en el Hombre para niños
