Describe 2 genetic disorders and discuss how they are inherited?

Answer 1

Marfan's syndrome is an autosomal dominant disorder of connective tissues. What is inherited is a defect in the chromosome 15q21, that codes the FBN1 gene. This gene is necessary for proper synthesis if a type of connective tissue called fibrillin. Patients have skeletal abnormalities, eye changes, cardiovascular problems, and a marked tendency to bruise.

Tay-Sachs disease is a lysosomal storage disorder, characterised by ganglioside accumulation. This is due to an enzyme deficiency in the lysosome that cannot digest the gangliosides and hence leads to progressive accumulation.

Answer 2

1. Cystic fibrosis is a genetic disorder caused by mutations in the CFTR gene, inherited in an autosomal recessive pattern. Both parents must pass on a copy of the mutated gene for the child to be affected.
2. Huntington's disease is a genetic disorder caused by a mutation in the HTT gene, inherited in an autosomal dominant pattern. If one parent carries the mutated gene, there is a 50% chance of passing it on to their child.