A genetic disorder is a medical condition caused by one or more gene mutations. A chromosomal abnormality or a mutation in a single gene (monogenic) or numerous genes (polygenic) might cause it. Because of the high number of genetic abnormalities, one out of every twenty-one people is affected with a "rare" genetic disorder (usually defined as affecting less than 1 in 2,000 people). The majority of genetic diseases are rare in and of themselves. The incidence of rare diseases is used to define them rather than unifying pathological or clinical criteria. Rare diseases cover a wide range of pathologies and pathogenesis mechanisms since they are distinguished by their low prevalence. Rare genetic diseases serve as a springboard for uncovering novel biology that has far-reaching implications for common human disorders. Changes in DNA are implicated in the cause of around 80% of rare disorders. Even if the symptoms aren't constantly evident, many diseases are present throughout a person's life.