One reason that diseases caused by recessive alleles remain in populations is that

Answer;

They often do not produce symptoms until a person has already had children.

Explanation;

One reason that diseases caused by recessive alleles remain in populations is that they often do not produce symptoms until a person has already had children.

Alleles are alternative forms of a gene.

A Recessive allele is an allele that produces its characteristic phenotype only when its paired allele is identical.