inherited disorders

what is a family tree?

a family tree, also called a pedigree chart, is a diagram representing family relationships across multiple generations.

what is an inherited disease?

an inherited disease is a condition that can be passed on genetically, through the inheritance of certain alleles.

what is cystic fibrosis?

cystic fibrosis is an inherited disorder of cell membranes.

it causes sticky mucus to build up in the lungs and digestive system.

is cystic fibrosis a dominant or recessive condition?

cystic fibrosis is a recessive condition.

what does it mean for an individual to be a carrier of cystic fibrosis?

they are heterozygous and only have one cystic fibrosis allele.

this means they can pass it onto their offspring, but do not have the condition themselves.

what is polydactyly?

an inherited disorder in which an individual can be born with extra fingers or toes.

is polydactyly a dominant or recessive condition?

polydactyly is a dominant condition.

what is in vitro fertilisation (IVF)?

in vitro fertilisation (IVF) is the process by which eggs are fertilised by sperm outside of the body.

the embryos are then grown in a laboratory until they are ready to be implanted into the mother’s womb.

what is embryo screening?

embryo screening is the process of taking a cell from an embryo and analysing its DNA for genetic abnormalities (e.g. the mutation that causes cystic fibrosis).

this is normally done during the in vitro fertilisation (IVF) process, before the embryo is implanted into the mother’s womb.

give 2 advantages of embryo screening.

1. it can reduce suffering by stopping children from being born with genetic disorders.

2. it can save the country a lot of money as treatment for inherited disorders is very expensive.

give 3 disadvantages of embryo screening.

1. screening against inherited disorders may imply that people with such disorders are undesirable, which is not fair or true.

2. embryo screening is a very expensive process and therefore is not available to all potential parents.

3. it could be a ‘slippery slope’ - people may begin screening for less and less harmful conditions, until they start screening for things likes height, gender, eye colour etc.