New News Biology #56

Why Do We Inherit Diseases From Our Family

Inherited Disorder = group of conditions passed on in alleles which are inherited from parents.

Inherited disorder - polydactyly (dominant allele):

A baby is born with extra fingers or toes, though it normally doesn’t cause other problems

Remember that polydactyly is caused by a dominant allele.

If a polydactyly and a normal bred, the offspring will have a 50% chance of being polydactyly and 50% chance of being normal.

Inherited disorder - cystic fibrosis (recessive allele, recessive condition)

Disorder of cell membranes -> result in sticky mucus, usually in the airways of lungs.

Although most people are homozygous dominant (with two normal alleles), 1 in 25 people are herterozygous (with one of each allele). These heterozygous people are carriers, because they may pass the disorder to their offspring.

IVF - in vitro fertilization - egg fertilized and grew into an embryo in a lab.

If we took a cell from the embryo and looked at its genes, which is known as embryo screening, we could know whether the embryo is carrying any genetic disorder. If by chance the embryo has a genetic disorder, than the parents and doctors may choose to discard the embryo in favor of one which doesn’t have any such disorders. The advantages of it are that it reduces overall suffering (because fewer people will have health problems), as well as saving money on treating disorders. However, it implies that people with genetic disorders are undesirable, and may result in future screening of other traits as well.