Dominant Traits and Diseases

Lynn B Jorde, University of Utah School of Medicine, Salt Lake City, Utah, USA

Published online: December 2008

DOI: 10.1002/9780470015902.a0001876.pub2

The principles of genetic dominance and recessiveness established by Gregor Mendel in his experiments with garden peas equally apply to human genetic diseases. For dominant diseases, the inheritance of one copy of the disease allele is sufficient to produce disease. Other factors, such as incomplete penetrance, variable expression, and delayed age of onset, further influence the expression of such diseases.

Keywords: dominant inheritance; recurrence risk; penetrance; variable expressivity

Figure 1. Outcomes of the mating of parents with the AA and aa genotypes.
Figure 2. Outcomes of the mating of parents with the Aa and aa genotypes. Affected genotypes among the offspring are shaded.
Figure 3. Outcomes of the mating of parents with the Aa and Aa genotypes. Affected genotypes among the offspring are shaded.
Figure 4. A pedigree illustrating the inheritance of brachydactyly, an autosomal dominant trait. Affected individuals shown in green. Males are represented by squares and females are represented by circles.
Figure 5. A pedigree illustrating reduced penetrance of an autosomal dominant allele. Affected individuals are shown in green. The lightly shaded individual in generation 2 has the disease-causing allele but does not develop the disease. Males are represented by squares and females are represented by circles.
Figure 6. A pedigree illustrating the phenomenon of anticipation (the age of each affected individual (green) is shown beneath the pedigree symbol). Males are represented by squares and females are represented by circles.
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 Further Reading
    book Jorde LB, Carey JC, Bamshad MJ and White RW (2006) Medical Genetics, 3rd edn. St Louis: Mosby.
    book Korf BR (2007) Human Genetics and Genomics, 3rd edn. Malden, MA: Blackwell Publishing.

Related Sub-Topics:

Gene and Genome Structure and Organisation | Statistical Methodology in Genetics | General Genetics and Disease
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Article Title: Dominant Traits and Diseases
 
How to Cite close
Jorde, Lynn B(Dec 2008) Dominant Traits and Diseases. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001876.pub2]