Many people have misconceptions about genetic terms and what these terms mean related to the inheritance of a health issue in a dog, a family of dogs or a breed. I wanted to take a moment to step back and discuss some of these commonly used terms to help people understand them more clearly.
Most genes (and the genes that will be tested for at Paw Print Genetics™ ) are located on the chromosomes contained in the nucleus found in most cells. Chromosomes come in 39 pairs (and thus, the genes come in pairs). One through 38 are the numbered pairs (called autosomes) the 39th pair are the sex chromosomes; females have two X chromosomes and males have an X and a Y chromosome. The X is larger and has more genes. Because males have only one copy of the X chromosome (and therefore only one copy of many genes found on the X chromosome), they are at risk of having certain diseases that are unlikely to affect females.
Autosomal conditions are found on one of the numbered chromosomes and X-linked conditions are found on the X chromosome. Each gene has a particular location on the chromosome called a locus. Different ...