- developmental processes
- development of body systems
- week 1
- week 2
- week 3
- weeks 4-8
- weeks 9-40
- teratogens
- problems with development
Section Links
Genes and Inheritance
- DNA, chromosomes, and genes
- patterns of inheritance
- threats to genetic integrity
- genetic disorders
- the language of genetics
- genetics and primary care
Chromosomes, found in the cell's nucleus, contain 30-35,000 genes that provide the information to make proteins. They are made out of DNA.
It is important to understand mitosis and meiosis to make sense of chromosomes and what can go wrong with them.
A good introduction to genetic biology has been written by the National Coalition for Health Professional Education in Genetics.
Patterns of Inheritance
- Principles of inheritance goes through the basics of Mendelian genetics and other introductory information.
- Inherited patterns of phenotype, such as autosomal dominant or recessive, are important.
- Multifactorial inheritance describes outcomes affected by more than one gene.
- Population genetics discusses specific genetic patterns and mutations affecting cultural groups.
- Pedigrees, or family trees, provide graphic representation of patterns of inheritance and predict risks of carrying certain alleles.
- Linkage analysis provides a measure of how alleles segregate with markers.
Threats to Genetic Integrity
Due to the immense complexity of DNA, both structurally and functionally, problems can occur. This can be during meiosis, mitosis, or involve random mutations.
Chromosome abnormalities affect large areas of genetic code.
Sun-chromosomal abnormalities
Genetic Disorders
Genetic disorders are diseases and conditions that result, in whole or in part, due to mutations or other changes in the DNA of a cell. They can be inherited from parents or result from new mutations.
Genetic disorders account for almost 50% of first trimester spontaneous abortions, 5% of all newborn births, and 40% of infant mortality.
Perhaps 10-12% of the population have enzyme deficiencies that make them hypersensitive to certain drugs.
Types of genetic disorders:
Chromosomal disorders are present in about 1:250 livebirths.
Single gene disorders, of which over 5000 have been identified, sre present in about 2% of livebirths.
Multifactorial, or polygenic, disorders, are present in about 2.5% of liveborn infants.
Environmental disorders can be caused by teratogens, carcinogens, or mutagens.
People often think that if you're born with it, you're stuck with it. Now, that's not so true anymore. Can have enzyme replacement therapy and other technologies.
The language used here
There are many words I would love to see removed.
"defect" is so hardcore. I prefer "problem" or "abnormality"
Genetic testing in primary care
Its coming soon, get ready!