Beyond the physical characteristics of an individual, the pairing of heterozygous alleles can sometimes translate into a higher risk of certain conditions such as birth defects or autosomal disorders (diseases inherited through genetics).
What do alleles cause?
Alleles contribute to the organism’s phenotype, which is the outward appearance of the organism. Some alleles are dominant or recessive. When an organism is heterozygous at a specific locus and carries one dominant and one recessive allele, the organism will express the dominant phenotype.
Can alleles cause genetic disorders?
The effects of the mutant version of the gene (allele) override the effects of the healthy version of the gene. So, the mutant allele causes disease symptoms even though a healthy allele is present.
What disease is caused by multiple alleles?
Schizophrenia: a common disease caused by multiple rare alleles.
Do alleles cause mutations?
In other cases, mutations in one allele may lead to a structural change in the protein that interferes with the function of the wild-type protein encoded by the other allele. These are referred to as dominant negative mutations. Some alleles can be associated with both a recessive and a dominant phenotype.
How do recessive alleles cause disorders?
Recessive genes are said to be inherited in either an autosomal recessive or X-linked pattern. If two copies of the abnormal gene are present, disease may develop. However, if only one abnormal gene is needed to produce a disease, it leads to a dominant hereditary disorder.
What are multiple alleles give an example?
An excellent example of multiple allele inheritance is human blood type. Blood type exists as four possible phenotypes: A, B, AB, & O. There are 3 alleles for the gene that determines blood type. (Remember: You have just 2 of the 3 in your genotype — 1 from mom & 1 from dad).