An inbred individual.
Since you all marry your cousins I bet you're a bunch of inbreds.
Bred within; innate.
Having an ancestry characterized by inbreeding.
Describing a strain produced through successive generations of inbreeding resulting in a population of genetically identical individuals which are homozygous at all genetic loci.
To breed or reproduce with those that are related.
To breed with those that share common traits or qualities.
To produce or generate within.