Certain Recessive Genes Cause Profound Deafness,and Individuals Homozygous for Such

Essay

Certain recessive genes cause profound deafness,and individuals homozygous for such genes are occasionally found in high frequencies among extended families in small,isolated communities.A deaf man and a deaf woman from two different communities,each having deaf parents,had three children,all of whom had normal hearing.
a)What are the parental genotypes?
b)What conclusions can be made about the allelic and gene interactions?