Congenital and inherited anomalies of the urinary system comprise a group of anatomical defects that, although uncommon, can have subclinical to serious functional consequences.
Many conditions are classified as familial disorders in particular breeds of dogs and cats. With continuing advancements in technology and research, more conditions are likely to be identified as having genetic determinants.
A congenital anomaly is a defect present at birth, and congenital conditions may or may not be inherited. Inherited anomalies are transmitted via genetic material from parent to offspring. This genetic material may include single-gene defects or chromosomal disorders or may be multifactorial.
Single-gene disorders involve 6 basic patterns of gene inheritance: autosomal recessive, autosomal dominant, X-linked recessive, X-linked dominant, Y-linked inheritance, and maternal mitochondrial inheritance.
Chromosomal disorders involve either an excess or lack of genes contained within a chromosome.
Multifactorial disorders involve interactions of several genes with external factors (eg, nutritional, radiation, viral, and toxic factors, as well as medications).
The mode of inheritance is known for many conditions, and more of the genes involved are being identified.
