Concept explainers
Familial hypercholesterolemia (FH) is an inherited trait in humans that results in higher-than-normal serum cholesterol levels [measured in milligrams of cholesterol per deciliter of blood (mg/dl)]. People with serum cholesterol levels that are roughly twice normal have a 25 times higher frequency of heart attacks than unaffected individuals. People with serum cholesterol levels three or more times higher than normal have severely blocked arteries and almost always die before they reach the age of 20. The following pedigrees show the occurrence of FH in four Japanese families:
a. | What is the most likely mode of inheritance of FH based on these data? Do any |
individuals in any of these pedigrees not fit your hypothesis? What special | |
conditions might account for such individuals? | |
b. | Why do individuals in the same |
symbols) show such variation in their levels of serum cholesterol? |
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Genetics: From Genes to Genomes
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