Management strategies for GSDs — MCQs

A 16-year-old woman presents to the emergency department for evaluation of acute vomiting and abdominal pain. Onset was roughly 3 hours ago while she was sleeping. She has no known past medical history. Her family history is positive for hypothyroidism and diabetes mellitus in her maternal grandmother. On examination, she is found to have fruity breath and poor skin turgor. She appears fatigued and her consciousness is slightly altered. Laboratory results show a blood glucose level of 691 mg/dL, sodium of 125 mg/dL, and elevated serum ketones. Of the following, which is the next best step in patient management?

A 10-year-old boy is brought to the emergency department due to vomiting and weakness. He is attending a summer camp and was on a hike with the other kids and a camp counselor. His friends say that the boy skipped breakfast, and the counselor says he forgot to pack snacks for the kids during the hike. The child’s parents are contacted and report that the child has been completely healthy since birth. They also say there is an uncle who would have to eat regularly or he would have similar symptoms. At the hospital, his heart rate is 90/min, respiratory rate is 17/min, blood pressure is 110/65 mm Hg, and temperature is 37.0°C (98.6°F). Physical examination reveals a visibly lethargic child with slight disorientation to time and place. Mild hepatosplenomegaly is observed but no signs of dehydration are noted. A blood sample is drawn, and fluids are started via an intravenous line. Lab report Serum glucose 44 mg/dL Serum ketones absent Serum creatinine 1.0 mg/dL Blood urea nitrogen 32 mg/dL Alanine aminotransferase (ALT) 425 U/L Aspartate aminotransferase (AST) 372 U/L Hemoglobin (Hb%) 12.5 g/dL Mean corpuscular volume (MCV) 80 fl Reticulocyte count 1% Erythrocyte count 5.1 million/mm3 Which of the following is most likely deficient in this patient?

A 22-year-old medical student decides to fast for 24 hours after reading about the possible health benefits of fasting. She read that blood glucose levels are maintained by metabolic processes such as hepatic glycogenolysis and hepatic gluconeogenesis during the initial 3 days of fasting. During the day, she did not suffer from the symptoms of hypoglycemia. Which of the following signaling molecules most likely stimulated the reaction which maintained her blood glucose after all her stored glucose was broken down and used up?

A 12-year-old girl comes to the clinic with a grossly enlarged abdomen. She has a history of frequent episodes of weakness, sweating, and pallor that are eliminated by eating. Her development has been slow. She started to walk unassisted at 2 years and was not performing well at school. Physical examination reveals a blood pressure of 100/60 mm Hg, heart rate of 80/min, and temperature of 36.9°C (98.4℉). On physical examination, the liver is enlarged, firm, and palpable up to the pelvis. The spleen and kidney are not palpable. Laboratory investigation reveals low blood glucose and pH with high lactate, triglycerides, ketones, and free fatty acids. The liver biopsy revealed high glycogen content. Hepatic glycogen structure was normal. The enzyme assay performed on the biopsy tissue revealed very low glucose-6-phosphatase levels. What is the most likely diagnosis?

A 5-month-old boy presents with increasing weakness for the past 3 months. The patient’s mother says that the weakness is accompanied by dizziness, sweating, and vertigo early in the morning. Physical examination shows hepatomegaly. Laboratory findings show an increased amount of lactate, uric acid, and elevated triglyceride levels. Which of the following enzymes is most likely deficient in this patient?

A 16-year-old boy comes to the physician because of muscle weakness and cramps for 5 months. He becomes easily fatigued and has severe muscle pain and swelling after 15 minutes of playing basketball with his friends. The symptoms improve after a brief period of rest. After playing, he sometimes also has episodes of reddish-brown urine. There is no family history of serious illness. Serum creatine kinase concentration is 950 U/L. Urinalysis shows: Blood 2+ Protein negative Glucose negative RBC negative WBC 1–2/hpf Which of the following is the most likely underlying cause of this patient's symptoms?

A newborn infant presents with severe weakness. He was born to a G1P1 mother at 40 weeks gestation with the pregnancy attended by a midwife. The mother's past medical history is unremarkable. She took a prenatal vitamin and folic acid throughout the pregnancy. Since birth, the child has had trouble breastfeeding despite proper counseling. He also has had poor muscle tone and a weak cry. His temperature is 99.5°F (37.5°C), blood pressure is 57/38 mmHg, pulse is 150/min, respirations are 37/min, and oxygen saturation is 96% on room air. Physical exam reveals poor muscle tone. The patient's sucking reflex is weak, and an enlarged tongue is noted. An ultrasound is performed, and is notable for hypertrophy of the myocardium. Which of the following is the most likely diagnosis?

A 15-year-old boy comes to the physician because of severe muscle cramps and pain for 3 months. He first noticed these symptoms while attending tryouts for the high school football team. Since then, he becomes easily fatigued and has severe muscle pain and swelling after 10 minutes of playing. However, after a brief period of rest, the symptoms improve, and he is able to return to the game. Two days ago, he had an episode of reddish-brown urine after playing football. There is no family history of serious illness. He appears healthy. Vital signs are within normal limits. Physical and neurological examinations show no abnormalities. Serum creatine kinase concentration is 333 U/L. Urinalysis shows: Blood 2+ Protein negative Glucose negative RBC negative WBC 1–2/hpf Which of the following is the most likely cause of this patient's symptoms?

A 24-year-old woman presents to the emergency department with abdominal pain that started while she was at the gym. The patient competes as a power lifter and states that her pain started after one of her heavier lifts. The patient has no significant past medical history and is currently taking a multivitamin and oral contraceptive pills. She smokes cigarettes and drinks alcohol regularly and is currently sexually active with multiple partners. Her temperature is 99°F (37.2°C), blood pressure is 85/55 mmHg, pulse is 125/min, respirations are 18/min, and oxygen saturation is 99% on room air. Physical exam is notable for right upper quadrant abdominal tenderness, acne, and muscle hypertrophy. Right upper quadrant ultrasound demonstrates a solitary heterogeneous mass. Which of the following other findings is most likely to be found in this patient?

A 1-year-old male with a history of recurrent pseudomonal respiratory infections and steatorrhea presents to the pediatrician for a sweat test. The results demonstrate a chloride concentration of 70 mEq/L (nl < 40 mEq/L). Which of the following defects has a similar AUTOSOMAL RECESSIVE mode of inheritance as the disorder experienced by this patient?