Patient #2: Mane is a 32-year-old mother of three complaining of fabgue and musc
ID: 3504632 • Letter: P
Question
Patient #2: Mane is a 32-year-old mother of three complaining of fabgue and muscle cramps with exercise. She had always blamed her intolerance to exercoise on her sedentary lifestyle. However she recently joined a gym and after a week of aerobics classes went to her physician, who ordered a series of blood tests. The blood work came back with abnormal results, leading to her muscle blopsy and referral to the metabolic clinic Levels ( normal,- decreased levels,+ increased levels) 3. The muscle biopsy showed an excess of glycogen in the muscle tissues. What is the most likely enzyme deficiency? option 4. Provide an explanation for why Marie would have an excess of glycogen in the muscle tissues. 5. If you wanted to test red blood cells for their ability to complete glycolysis, what compound would you try to detect? 6. If you had some of Marie's red blood cells in a test tube, what compound could you add to enable these cells to produce pyruvate? 7. Provide an explanation for why both Ann and Marie might have lower than normal red blood cell concentrations.Explanation / Answer
3. This is the case of phosphofructokinase deficiency. This disease is known as type VII glycogen storage disease or Tarui disease.
4. Marie has excess of glygogen in the muscle tissue because she lacks the enzyme phosphofructokinase. This enzyme is a rate limiting enzyme of glycolysis (glucose breakdown). When there is high level of glucose in the cell, then there is no need to break the glycogen to produce glucose. So, glycogen molecules become excess in the muscle tissue of Marie.
5. The end product of glycolysis is pyruvate. So, pyruvate should be tried to detect for determining the ability of RBC to complete glycolysis.
6. 1,3-bisphosphoglycerate is the compound, which can be used to enable these cells to produce pyruvate. This compound is a precursor of phosphoenl pyruvate.
7. The study about Ann is not given here but Marie has lower RBC concentration because the the enzyme phosphofructokinase in RBC is slightly active and help RBC to gain its energy requirement by glycolysis. As the RBC also stores the glycogen they becomes heavier and thus degraded.