Final answer:
To establish a successful and cost-effective screening program for detecting adult heterozygous carriers of an autosomal recessive disease, an effective treatment being available for the disorder is not a requirement.
Step-by-step explanation:
To establish a successful and cost-effective screening program for detecting adult heterozygous carriers of an autosomal recessive disease, the important factors include: detecting the disorder is possible in the fetus, the disease is clinically significant, a high-risk population can be identified, and genetic counseling is provided with the testing. However, an effective treatment being available for the disorder is not a requirement for establishing a successful program.