47: Factor V Leiden Disorder

TEKS B.8B

TEKS B.8B

: Science concepts--mechanisms of genetics. The student knows the role of

nucleic acids and the principles of inheritance and variation of traits in Mendelian and non-

Mendelian genetics. The student is expected to predict possible outcomes of various genetic

combinations using monohybrid and dihybrid crosses, including non-Mendelian traits of

incomplete dominance, codominance, sex-linked traits, and multiple alleles.

Answer

1.

What is the patient’s genotype?

Heterozygous, or Aa (Students may use any letter.)

2.

Is the patient affected by the disorder? Explain your thinking.

Yes, the patient is affected by

the disease because it is an autosomal dominant disorder. This means only one dominant

allele is needed for someone to have the disorder.

3.

What does the diagnosis tell you about the patient’s parents’ genotypes or phenotypes?

Explain your thinking.

At least one parent must be affected by the disorder. That parent could

be homozygous dominant or heterozygous for the trait.

Teacher Notes

Discussing genetics requires highly specialized vocabulary. The key to being able to answer

an item relies on students’ ability to process the meaning of

autosomal dominant

.

Autosomal

refers to non-sex genes or chromosomes, and

dominant

refers to an inheritance pattern that

requires only one version of the allele to express a specific phenotype. Dominant phenotypes

can be expressed as a result of two different genotypes, whereas recessive phenotypes can

only be expressed by a single genotype in autosomal traits. Sex-linked, recessive traits may be

displayed with only one copy of the allele in males.