Medical genetics was originally focused on rare hereditary disorders but has expanded with advances in genomics. Genomic medicine now considers personalized healthcare, predictive medicine, gene therapies, and interactions between genes, environments, and variations. Genetic diseases are categorized as chromosome disorders involving large mutations, single-gene disorders from small mutations of individual genes, and multifactorial disorders with a genetic component but no clear inheritance pattern. As the database of human genetic variation expands, genomics will lead to further discoveries improving public health and medicine.

1. What Is Medical Genetics?
Medical Genetics was considered
as the detection and treatment of a
few phenotypically rare
hereditary disorders.

2. Pre- & perinatal diagnosis
Treatment of abnormalities
in development

3. Genomic Medicine Arises
Advances in Genomics,
Proteomics, and DNA
Sequencing allowed for the
development of
Genomic Medicine; this includes:
• Personalized health care
• Predictive (precision) medicine
• Previvor ship – surviving a
condition before it happens
• Potential application of gene
therapies

4. Today, Genetics and Genomics Go
Hand in Hand
Applying the analysis of the human
genome and its products
to medicine, we now consider:
Gene interactions
Control of gene expression
Environmental interaction
Gene variations interactions

5. Categories of Genetic Diseases
Chromosome
disorders
Multifactorial
disorders
Single-gene
disorders

6. Chromosome Disorders
Are large-scale mutations of the
chromosomes
• Excess or deficiency of genes –
e.g. Down syndrome (trisomy 21)
• No mutation in individual genes
• Duplication or deletion of smaller
segments

7. Single-gene Disorders
Localized small-scale mutations
• Mutation of individual genes (e.g.
sickle
cell anemia, cystic fibrosis)
• Follow classic inheritance
patterns
(autosomal recessive/dominant, X-
linked)

8. Multifactorial Disorders
Hard to pin down
• Majority of diseases have a
genetic
component
• Does not fit inheritance patterns
expected
in single gene mutations

9. The ever expanding database of
human genetic variation and our
understanding of genomics will
inevitably lead to extensive
discovery
and development in public health
and the availability of tools in the
practice of medicine