Chromosome 19 spans more than 61.7 million base pairs, the building material of DNA.

It is considered the most gene-rich chromosome containing roughly 1,500 genes, despite accounting for only 2 percent of the human genome.

[4][5] The following are some of the gene count estimates of human chromosome 19.

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.