C. Duncan is a Caucasian male (age 14) that is brought to yourattention because his family concerned about his inability toperform strenuous exercise. Duncan suffered severe muscle crampingduring his P.E. classes but is normal if at doing routine physicalactivity or performing light to moderate exercise. A physicalexamination showed poorly developed muscle tissue, but his liversize was normal. A fasting glucose level check showed normallevels.
- Duncan’s blood was also tested for alanine levels and showed adecrease in alanine after exercise, indicating that Duncan’s musclecells were taking up alanine. In a normal individual, alaninelevels would be expected to rise in the muscle duringexercise.
Why would the alanine concentrationsin the blood increase in a normal person?
How would you explain the alanineconcentration results for Duncan’s test?
- Explain why Duncan does not suffer from abnormal blood glucoselevels.
- You suggest that perhaps Duncan should refrain from strenuousexercise. But if he cannot avoid it, what can you advise him to doduring exercise to alleviate some of his suffering? Explain.
You decide that a genetic analysis is in order to discover thesource of Duncan’s problems. Suggest at two gene sequences youwould inspect, and what you would look for in these genes, toinvestigate the problem.
