PENDRED SYNDROME:
INHERITANCE
Pendred Syndrome is a recessive disease. Therefore, both parents must have the disease or at least one recessive allele (carry the disease) in order for the offspring to have it. Pendred Syndrome is not sex-influenced because the offspring of parents cannot have the disease unless both parents have the recessive alleles. If one parent has the recessive allele and the other parent does not it will not be sex influenced for the offspring. Also, either sex of offspring can obtain this disease.
As demonstrated in this diagram, this is how a child may inherit Pendred syndrome. This genetic disease is recessive like mentioned before. Both parents have one dominant allele and one recessive allele making both of them heterozygous for the disease/carriers. The diagram shows that with this heterozygous cross, 1/4 of the offspring is affected, 1/2 of the offspring are carriers of the disease, and the other 1/4 is unaffected.
Take a look at this Punnett Square:
GENOTYPES/PHENOTYPES
- PP = unaffected child
- Pp = carrier child
- pp = affected child
AS YOU CAN SEE, BOTH PARENTS MUST HAVE AT LEAST ONE
RECESSIVE ALLELE ("p") IN ORDER TO PRODUCE AFFECTED OFFSPRING
Citations:
http://tappergen564s14.weebly.com/gene.html
- Pendred syndrome & the SLC26A4
http://www.ncbi.nlm.nih.gov/books/NBK1467/ - NCBI
http://www.biologyjunction.com/apgenetics_solutions.htm - Punnett Square
http://www.ncbi.nlm.nih.gov/books/NBK1467/ - NCBI
http://www.biologyjunction.com/apgenetics_solutions.htm - Punnett Square