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Genetics Exam #3

Terms in this set (300)

In humans, Occipital horn syndrome OHS) is a rare X-linked recessive disorder that is caused by a deficiency in the transport of the essentail mineral copper and associated with mutations in the ATP7A gene. The dominant and recessive alleles for OHS are represented by H and h. Acatalasia is an autosomal recessive condition that results from mutations of the gene producing catalase, and presents with recurrent periodontal infections. A and a allele symbols represent the Acatalasia alleles.

A healthy man named Simon is married to a healthy woman named Sally. Simon's parents are healthy, but his brother Sean has OHS, and his sister Syndey has Acatalasia. Sally's brother Scott has Acatalasia and OHS. Sally's father has OHS, but her mother is normal.

The pedigree shown below is incomplete. For each individual, let the left side of the circle/square represent their phenotype for OHS, and the right side represent their phenotype for Acatalasia. Darkened areas mean they are affected by the disorder.

A. Complete the pedigree to reflect ALL of the data and individuals described above including filling in or leaving symbols as indicated.

B. Using typical numbering system designations state the genotypes of the following individuals as completely as possible. Be sure to include information for both genes. Using H and h for OHS; A and a for Acatalasia; include X and Y symbols in addition of the genes are on sex chromosomes.

I-1 = ?
I-3 = ?
I-4 = ?
II-1 = ?

C. Determine the probabilities that SImon and Sally's first child will be a Boy with OHS and Acatalasia.