What genetic factor is considered responsible for the increased incidence of certain diseases in populations with higher rates of consanguinity?

Consanguinity refers to mating between individuals who are closely related by blood, which increases the likelihood that both parents carry the same recessive alleles for specific genetic traits or disorders. In populations with higher rates of consanguinity, the incidence of autosomal recessive diseases is significantly elevated because there is a greater chance that both parents will pass on the same allele to their offspring.

When an individual inherits two copies of a recessive allele (one from each parent), they may express the associated phenotype, which can lead to the development of certain genetic disorders. These can include conditions like cystic fibrosis, sickle cell anemia, and Tay-Sachs disease, among others.

While autosomally dominant traits can also affect populations, they require only one copy of the dominant allele to express the condition, making them less likely to have a marked increase due to consanguinity. Chromosomal aberrations can occur sporadically and are not directly influenced by relationships between parents, while environmental influences stem from factors outside genetics and do not relate specifically to consanguinity. Thus, recessive alleles are the primary genetic factor responsible for the increased incidence of certain diseases in populations with higher rates of relatedness.