How is a genetic disease characterized?

A genetic disease is characterized primarily by being inherited from the parents. This means that the genetic material (DNA) carrying specific alterations or mutations associated with the disease is passed down from one or both parents to their offspring. Genetic diseases can manifest due to single-gene mutations, chromosomal abnormalities, or multifactorial inheritance, and their inheritance patterns can vary widely, including autosomal dominant, autosomal recessive, or X-linked modes.

While the other options might describe certain aspects of some diseases, they do not accurately represent the defining feature of a genetic disease. For instance, autoimmune disorders (the first option) are related to the immune system mistakenly attacking the body, rather than being directly tied to inherited genetic factors. The undetectability during early stages (the third option) does not apply universally to all genetic diseases, as some can be identified through genetic testing or at birth. Lastly, the idea that a genetic disease is always fatal (the fourth option) is misleading, as many genetic conditions can be managed or have varying degrees of severity, with individuals often leading fulfilling lives despite some genetic predispositions.