Chromosome 3 spans more than 198 million base pairs (the building material of DNA) and represents about 6.5 percent of the total DNA in cells.

The following are some of the gene count estimates of human chromosome 3.

Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction).

So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes.

Partial list of the genes located on p-arm (short arm) of human chromosome 3: Partial list of the genes located on q-arm (long arm) of human chromosome 3: The following diseases and disorders are some of those related to genes on chromosome 3: