In humans, the chromosomes occur in pairs and a typical somatic cell would contain 23 pairs of chromosomes in the nucleus. Each of these pairs has a characteristic length and banding pattern. There are two types of chromosomes: autosomes and allosomes. There are also two sets: the first set comes from the mother and the second set, from the father. Using idiograms, each chromosome may be identified one from the other based on the relative size and the banding pattern.
Chromosome 13 is an arocentric autosome. It spans almost 114 million base pairs (i.e. about 3.5 to 4 % of the total DNA). It is likely to contain about 300 or less than 400 genes. Some of the genes are CKAP2 (coding for cytoskeleton-associated protein 2), EDNRB (for endothelin receptor type B), RB1 (for retinoblastoma 1), and PCCA (for propionyl Coenzyme A carboxylase, alpha polypeptide).
Some of the diseases and disorders related to the genes on chromosome 13 include 13q deletion syndrome, heterochromia, nonsyndromic deafness, schizophrenia, retinoblastoma, Waardenburg syndrome, and Young–Madders syndrome.