LO: Describe the structure of a chromosome

• Human genome made up of nuclear and mitochondrial DNA sequences
• Most human cells contain 46 chromosomes
• Less than 20000 protein-coding genes

LO: Describe how genes are organised on the chromosome

Human Genome Project

• Determine nucleotide sequence of the transcriptionally active parts of the human genome
• Define the locus (position) of each gene on the chromosomes

Gene

• Promotor region
• Exons (expressed) and introns (not expressed)
• Transcription termination sequence

LO: Describe the major modes of Mendelian-monogenic inheritance

Skills for Genetic Medicine

• History taking
• Family history diagram (pedigree) construction
• Examination
• Lab testing
• Diagnosis
• Counselling
• Follow up

Familial risks

• Incidence of a disorder in relatives compared with incidence in the general population

Twin studies

• Incidence of the phenotype in monozygotic compared with dizygotic twins

Evidence from these types of studies can estimate heritability of a condition

Heritability - proportion of the variance in a characteristic attributed to genetic factors