Management strategies for GSDs US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Management strategies for GSDs. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Management strategies for GSDs US Medical PG Question 1: 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. Administer IV fluids and insulin (Correct Answer)
- B. Initiate basal-bolus insulin regimen
- C. Initiate insulin glargine 10 units at bedtime only
- D. Initiate oral antidiabetic medications
- E. Initiate insulin aspart at mealtimes only
Management strategies for GSDs Explanation: ***Administer IV fluids and insulin***
- The patient presents with **fruity breath**, **altered consciousness**, **hyperglycemia (691 mg/dL)**, **hyponatremia**, and **elevated serum ketones**, which are classic signs of **diabetic ketoacidosis (DKA)**.
- The immediate management for DKA involves aggressive **intravenous fluid resuscitation** to correct dehydration and hypovolemia, followed by a continuous **intravenous insulin infusion** to lower blood glucose and suppress ketogenesis.
*Initiate basal-bolus insulin regimen*
- A **basal-bolus insulin regimen** is appropriate for long-term management of diabetes but is not the immediate treatment for acute DKA, which requires continuous intravenous insulin.
- This approach does not address the severe dehydration and electrolyte imbalances seen in DKA, which need urgent fluid replacement.
*Initiate insulin glargine 10 units at bedtime only*
- **Insulin glargine** is a long-acting insulin used for basal insulin coverage, typically in the chronic management of diabetes.
- This dose is insufficient to manage acute DKA, and it also fails to address the critical need for fluid resuscitation.
*Initiate oral antidiabetic medications*
- **Oral antidiabetic medications** are suitable for individuals with type 2 diabetes or milder forms of insulin resistance, not for acute DKA.
- They are ineffective in severe hyperglycemia and metabolic acidosis characteristic of DKA, and do not address dehydration.
*Initiate insulin aspart at mealtimes only*
- **Insulin aspart** is a rapid-acting insulin used to cover mealtime glucose excursions.
- Administering it only at mealtimes is inadequate for acute DKA, which requires continuous insulin infusion and aggressive fluid management.
Management strategies for GSDs US Medical PG Question 2: 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. Acyl-CoA dehydrogenase (Correct Answer)
- B. α-glucosidase
- C. Glucose-6-phosphatase
- D. Acetyl-CoA carboxylase
- E. Nicotinic acid
Management strategies for GSDs Explanation: ***Acyl-CoA dehydrogenase***
- This patient presents with **hypoglycemia** (44 mg/dL) and **absent ketone bodies** after prolonged fasting, along with elevated **liver transaminases** and **hepatosplenomegaly**, which are classic signs of a **fatty acid oxidation disorder**.
- A deficiency in **acyl-CoA dehydrogenase**, particularly **medium-chain acyl-CoA dehydrogenase (MCAD)**, prevents adequate fatty acid breakdown for energy and ketone production, leading to **hypoketotic hypoglycemia** during periods of fasting.
*α-glucosidase*
- A deficiency in **α-glucosidase** (Pompe disease) leads to the accumulation of **glycogen** in lysosomes, primarily affecting muscles, heart, and liver.
- While it can cause hepatomegaly and muscle weakness, it typically presents with **cardiomyopathy** and does not directly cause hypoketotic hypoglycemia.
*Glucose-6-phosphatase*
- A deficiency in **glucose-6-phosphatase** (Von Gierke disease) is a type of **glycogen storage disease** characterized by severe **fasting hypoglycemia with lactic acidosis**, **massive hepatomegaly**, and **hyperlipidemia**.
- Unlike fatty acid oxidation disorders, Von Gierke disease typically presents with **lactic acidosis** as the predominant metabolic derangement, and patients often have a **doll-like face** and **growth retardation** from chronic presentation.
*Acetyl-CoA carboxylase*
- **Acetyl-CoA carboxylase** is a key enzyme in **fatty acid synthesis**, not fatty acid oxidation.
- A deficiency would primarily impair the body's ability to synthesize fatty acids, which is not consistent with the hypoketotic hypoglycemia observed here.
*Nicotinic acid*
- **Nicotinic acid** (niacin or vitamin B3) is a precursor to **NAD+** and **NADP+**, coenzymes involved in various metabolic reactions, including fatty acid synthesis and breakdown.
- While a deficiency (pellagra) can cause dermatitis, diarrhea, and dementia, it does not directly lead to **hypoketotic hypoglycemia** or fatty liver disease.
Management strategies for GSDs US Medical PG Question 3: 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. Adenosine diphosphate
- B. Acetyl CoA (Correct Answer)
- C. Acetate
- D. Citrate
- E. Adenosine monophosphate
Management strategies for GSDs Explanation: ***Acetyl CoA***
- **Acetyl CoA** is the key **allosteric activator of pyruvate carboxylase**, the first committed enzyme of gluconeogenesis that converts pyruvate to oxaloacetate.
- During prolonged fasting after glycogen stores are depleted, the body shifts to **fatty acid oxidation** (β-oxidation), which produces large amounts of **Acetyl CoA**.
- High **Acetyl CoA** levels signal that fat is being oxidized for energy, and simultaneously **activate gluconeogenesis** to maintain blood glucose for glucose-dependent tissues (brain, RBCs).
- This is the primary signaling mechanism that directly stimulates the gluconeogenic pathway after glycogen is exhausted.
*Adenosine monophosphate (AMP)*
- **AMP** levels rise during energy depletion and activate **AMP-activated protein kinase (AMPK)**.
- However, AMPK **inhibits gluconeogenesis** (not stimulates it) because gluconeogenesis is an **ATP-consuming** anabolic process (requires 6 ATP per glucose).
- AMPK promotes ATP-generating catabolic processes like fatty acid oxidation, but suppresses ATP-consuming processes like gluconeogenesis and fatty acid synthesis.
*Adenosine diphosphate (ADP)*
- **ADP** accumulates when ATP is hydrolyzed and signals moderate energy deficit.
- ADP is primarily a substrate for ATP regeneration via oxidative phosphorylation and does not directly regulate gluconeogenesis.
- Its role in metabolic regulation is less specific than allosteric activators like Acetyl CoA.
*Acetate*
- **Acetate** can be converted to Acetyl CoA but is not a direct signaling molecule for gluconeogenesis.
- It is a minor metabolite that may be produced in specific conditions (e.g., alcohol metabolism, ketoacidosis) but does not play a primary role in fasting-induced glucose homeostasis.
*Citrate*
- **Citrate** is a Krebs cycle intermediate that inhibits **phosphofructokinase-1 (PFK-1)** in glycolysis, thus reducing glucose breakdown.
- While citrate inhibition of glycolysis indirectly favors gluconeogenesis by preventing futile cycling, citrate does not **directly activate** gluconeogenic enzymes.
- Citrate primarily signals energy sufficiency and promotes fatty acid synthesis in the fed state, not fasting gluconeogenesis.
Management strategies for GSDs US Medical PG Question 4: 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. Pompe's disease
- B. Cori's disease
- C. Hereditary hemochromatosis
- D. Von-Gierke's disease (Correct Answer)
- E. McArdle disease
Management strategies for GSDs Explanation: ***Von-Gierke's disease***
- The combination of **hepatomegaly**, **hypoglycemia** (causing weakness, sweating, pallor), **lactic acidosis**, **hyperlipidemia**, and elevated ketones points to a severe defect in glucose metabolism.
- **Very low glucose-6-phosphatase levels** on liver biopsy and normal hepatic glycogen structure are pathognomonic for Von-Gierke's disease (Glycogen Storage Disease Type I).
*Pompe's disease*
- This is a **lysosomal storage disease** affecting **alpha-1,4-glucosidase**, leading to glycogen accumulation in lysosomes.
- It primarily affects the **heart** and skeletal muscles and would not present with severe lactic acidosis and hyperlipidemia.
*Cori's disease*
- This is **Glycogen Storage Disease Type III**, caused by a deficiency in the **debranching enzyme** (amylo-alpha-1,6-glucosidase).
- While it can cause hepatomegaly and hypoglycemia, the hepatic glycogen structure would be abnormal due to incompletely debranched glycogen, and glucose-6-phosphatase levels would be normal.
*Hereditary hemochromatosis*
- This is an **iron overload disorder** leading to iron deposition in organs like the liver, heart, and pancreas.
- It would present with symptoms related to organ damage from iron accumulation, such as liver cirrhosis and diabetes, not the metabolic derangements seen here.
*McArdle disease*
- This is **Glycogen Storage Disease Type V**, due to a deficiency in **muscle glycogen phosphorylase**.
- It primarily causes exercise-induced muscle pain, cramping, and fatigue due to an inability to break down muscle glycogen for energy, not systemic metabolic disturbances or hepatomegaly.
Management strategies for GSDs US Medical PG Question 5: 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. Hepatic glycogen phosphorylase
- B. Debranching enzyme
- C. Glucose-6-phosphatase (Correct Answer)
- D. Muscle glycogen phosphorylase
- E. Lysosomal α-1,4-glucosidase
Management strategies for GSDs Explanation: ***Glucose-6-phosphatase***
- The constellation of **hypoglycemia** (weakness, dizziness, sweating, vertigo, especially early morning), **hepatomegaly**, **lactic acidosis**, **hyperuricemia**, and **hypertriglyceridemia** are classic features of **Type I glycogen storage disease (von Gierke disease)**, which is caused by a deficiency of **glucose-6-phosphatase**.
- This enzyme is crucial for the final step of both **glycogenolysis** and **gluconeogenesis**, releasing free glucose into the bloodstream; its deficiency leads to an inability to maintain normal blood glucose levels during fasting and accumulation of glucose-6-phosphate, which shunts into other metabolic pathways.
*Hepatic glycogen phosphorylase*
- Deficiency in **hepatic glycogen phosphorylase** (Type VI glycogen storage disease, Hers disease) would cause **hepatomegaly** and **hypoglycemia**, but typically does not present with severe **lactic acidosis**, **hyperuricemia**, or **hypertriglyceridemia** to the same degree as von Gierke disease.
- The primary defect is in breaking down glycogen, leading to its accumulation in the liver, but the products of glycolysis can still exit the liver via gluconeogenesis.
*Debranching enzyme*
- Deficiency in **debranching enzyme** (Type III glycogen storage disease, Cori or Forbes disease) causes **hepatomegaly** and **hypoglycemia**, but usually presents with milder symptoms and less severe **lactic acidosis**, **hyperuricemia**, and **hypertriglyceridemia**.
- Patients often present with symptoms similar to Type I, but muscle involvement is also common, and **glycogen structures with short outer branches** are characteristic.
*Muscle glycogen phosphorylase*
- Deficiency in **muscle glycogen phosphorylase** (Type V glycogen storage disease, McArdle disease) primarily affects **skeletal muscle**, leading to exercise intolerance, muscle pain, and myoglobinuria.
- It does not typically cause **hypoglycemia** or **hepatomegaly**, as the liver enzyme is functional, and the symptoms described are systemic rather than muscle-specific.
*Lysosomal α-1,4-glucosidase*
- Deficiency in **lysosomal α-1,4-glucosidase** (Type II glycogen storage disease, Pompe disease) primarily affects the **heart, muscle, and liver**, causing severe **cardiomyopathy**, hypotonia, and **hepatomegaly**.
- While it involves glycogen accumulation, it typically does not present with **hypoglycemia** (as cytoplasmic glycogen metabolism is intact), **lactic acidosis**, or the specific metabolic derangements seen in this patient.
Management strategies for GSDs US Medical PG Question 6: 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. Medium-chain acyl-CoA dehydrogenase deficiency
- B. Myophosphorylase deficiency (Correct Answer)
- C. Low levels of triiodothyronine and thyroxine
- D. Acid maltase deficiency
- E. CTG repeat in the DMPK gene
Management strategies for GSDs Explanation: ***Myophosphorylase deficiency***
- This condition (McArdle disease) is an **autosomal recessive disorder** of glycogen metabolism characterized by a defect in **glycogenolysis**, specifically the breakdown of muscle glycogen. This leads to impaired energy production during exercise.
- The classic presentation includes **exercise-induced muscle pain, stiffness, cramps, fatigue**, and sometimes **myoglobinuria** (reddish-brown urine due to myoglobin release from damaged muscle), which is consistent with the patient's symptoms and elevated **creatine kinase**.
*Medium-chain acyl-CoA dehydrogenase deficiency*
- This is a disorder of **fatty acid oxidation** that primarily affects the liver, leading to episodes of **hypoketotic hypoglycemia** during fasting or illness.
- It does not typically present with isolated exercise-induced muscle pain and myoglobinuria.
*Low levels of triiodothyronine and thyroxine*
- **Hypothyroidism** can cause generalized muscle weakness, fatigue, and muscle cramps, but it is usually associated with other systemic symptoms like weight gain, cold intolerance, and constipation.
- While it can cause elevated CK, it generally does not present with acute, exercise-induced muscle pain and myoglobinuria in the manner described.
*Acid maltase deficiency*
- This (Pompe disease) is a lysosomal storage disorder affecting glycogen metabolism, but it results from a deficiency of **acid alpha-glucosidase (acid maltase)**.
- The infantile form presents with severe hypotonia and cardiomyopathy, while the juvenile and adult forms typically cause **proximal muscle weakness** and respiratory insufficiency, rather than exercise-induced muscle pain and myoglobinuria.
*CTG repeat in the DMPK gene*
- This genetic defect is associated with **myotonic dystrophy type 1 (Steinert disease)**, an autosomal dominant disorder.
- Key features include **myotonia** (delayed relaxation of muscles), muscle weakness, cataracts, and cardiac conduction abnormalities, which are distinct from the patient's presentation of exercise-induced cramps and myoglobinuria without myotonia.
Management strategies for GSDs US Medical PG Question 7: 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. Acid maltase deficiency (Correct Answer)
- B. Familial hypertrophic cardiomyopathy
- C. Clostridium tetani infection
- D. Spinal muscular atrophy type I disease
- E. Clostridium botulinum infection
Management strategies for GSDs Explanation: ***Acid maltase deficiency***
- This condition is also known as **Pompe disease**. It is a **lysosomal storage disease** that presents in infancy with **cardiomegaly**, **macroglossia**, **hypotonia**, and **respiratory failure**, all of which are consistent with the patient's presentation.
- The deficiency in **acid alpha-glucosidase (acid maltase)** leads to glycogen accumulation in lysosomes, particularly in muscle cells, causing impaired muscle function, including the heart.
*Familial hypertrophic cardiomyopathy*
- While it causes **myocardial hypertrophy**, it typically does **not present with profound generalized hypotonia, macroglossia, or feeding difficulties** as the primary symptoms in infancy.
- This condition is usually due to **sarcomeric protein mutations** and lacks the widespread systemic muscle involvement seen in Pompe disease.
*Clostridium tetani infection*
- This infection causes **tetanus**, characterized by **severe muscle spasms, trismus (lockjaw), and opisthotonus**, rather than hypotonia and weakness.
- It would also typically involve a history of a **puncture wound or contaminated injury**, which is not mentioned.
*Spinal muscular atrophy type I disease*
- This is characterized by **severe hypotonia** and **muscle weakness** due to the degeneration of anterior horn cells.
- However, **cardiomegaly and macroglossia are not typical features** of spinal muscular atrophy.
*Clostridium botulinum infection*
- This infection causes **flaccid paralysis** and weakness, usually presenting with **constipation**, **weak cry**, and **difficulty feeding**, by preventing acetylcholine release at neuromuscular junctions.
- However, **cardiomyopathy and macroglossia are not characteristic** of botulism.
Management strategies for GSDs US Medical PG Question 8: 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. CTG repeat in the DMPK gene
- B. Myophosphorylase deficiency (Correct Answer)
- C. Dystrophin gene mutation
- D. Thyroid hormone deficiency
- E. Acid maltase deficiency
Management strategies for GSDs Explanation: ***Myophosphorylase deficiency***
- This condition (also known as **McArdle disease**) presents with **exercise-induced muscle cramps, pain, and fatigue** immediately after initiating activity, with a "second wind" phenomenon where symptoms improve after resting.
- The elevated **creatine kinase** and **reddish-brown urine** (indicating **myoglobinuria** due to rhabdomyolysis) are classic findings after strenuous activity in this glycogen storage disorder.
*CTG repeat in the DMPK gene*
- This describes **myotonic dystrophy type 1**, which presents with **myotonia** (delayed muscle relaxation), muscle weakness, and often involves multiple organ systems.
- While it causes muscle weakness, it does not typically present with acute, exercise-induced pain, cramping, and rhabdomyolysis in this manner.
*Dystrophin gene mutation*
- This is characteristic of **Duchenne or Becker muscular dystrophy**, which are progressive muscle weakness disorders.
- They typically cause **progressive proximal muscle weakness** and atrophy, not acute, intermittent, exercise-induced pain and cramping with a "second wind" phenomenon.
*Thyroid hormone deficiency*
- **Hypothyroidism** can cause muscle cramps, weakness, and elevated creatine kinase, but these symptoms are usually chronic and progressive, not acutely exercise-induced with improvement after a short rest.
- It would also present with other systemic symptoms like fatigue, weight gain, and cold intolerance, which are not described.
*Acid maltase deficiency*
- Also known as **Pompe disease**, this is a glycogen storage disorder that primarily affects infants and can present in adults with **proximal muscle weakness**, respiratory insufficiency, and cardiac involvement.
- It does not typically present with acute, exercise-induced muscle cramps, pain, and rhabdomyolysis followed by a "second wind" phenomenon like McArdle disease.
Management strategies for GSDs US Medical PG Question 9: 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. Elevated viral core antigen
- B. Elevated alpha fetoprotein
- C. Increased pigmentation in flexural areas
- D. Prolonged PT and PTT
- E. Increased LDL and decreased HDL (Correct Answer)
Management strategies for GSDs Explanation: ***Increased LDL and decreased HDL***
- This patient's presentation is most consistent with **hepatic adenoma rupture** related to **anabolic steroid use** (suggested by powerlifting, muscle hypertrophy, and acne) combined with oral contraceptive use.
- **Anabolic steroids have well-documented effects on lipid metabolism**, characteristically causing **decreased HDL cholesterol** and **increased LDL cholesterol**, which significantly increases cardiovascular risk.
- This lipid pattern is one of the most consistent and clinically significant metabolic effects of anabolic steroid abuse and would be expected in this patient.
*Elevated alpha fetoprotein*
- **Alpha-fetoprotein (AFP)** is a tumor marker for **hepatocellular carcinoma (HCC)**, not hepatic adenoma.
- While anabolic steroids can cause hepatic adenomas and rarely HCC, this acute presentation with hemodynamic instability in a young woman on oral contraceptives is classic for **ruptured hepatic adenoma**, which does **not** elevate AFP.
- AFP elevation would not be expected in this clinical scenario.
*Elevated viral core antigen*
- Elevated viral core antigen would indicate active **hepatitis B infection**, a risk factor for chronic liver disease and HCC.
- There is no evidence in this vignette to suggest viral hepatitis, and this would not be related to the acute presentation or anabolic steroid use.
*Increased pigmentation in flexural areas*
- **Acanthosis nigricans** (hyperpigmentation in flexural areas) is associated with insulin resistance and certain malignancies.
- While anabolic steroids can affect glucose metabolism, acanthosis nigricans is not a characteristic finding of steroid use or hepatic adenoma.
*Prolonged PT and PTT*
- While severe liver dysfunction can cause coagulopathy with prolonged PT and PTT, this is not the most characteristic finding in hepatic adenoma.
- The acute presentation is more likely due to hemorrhage from adenoma rupture rather than chronic liver failure with synthetic dysfunction.
Management strategies for GSDs US Medical PG Question 10: 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?
- A. Abnormal production of type IV collagen
- B. Trinucleotide repeat expansion of CAG on chromosome 4
- C. Mutated gene for mitochondrial-tRNA-Lys
- D. Accumulation of glycogen in the lysosome (Correct Answer)
- E. Inability to convert carbamoyl phosphate and ornithine into citrulline
Management strategies for GSDs Explanation: ***Accumulation of glycogen in the lysosome***
- The patient's symptoms (recurrent **pseudomonal respiratory infections**, **steatorrhea**, and elevated sweat chloride) are classic for **cystic fibrosis (CF)**, an **autosomal recessive** disorder.
- Accumulation of glycogen in the lysosome describes **Pompe disease (Type II Glycogen Storage Disease)**, which is also an **autosomal recessive** disorder, making this the correct answer.
*Abnormal production of type IV collagen*
- This defect is characteristic of **Alport syndrome**, which is predominantly **X-linked dominant** (~80-85% of cases), though autosomal recessive forms exist.
- The question context and typical board exam framing classify this as X-linked, not autosomal recessive.
- Alport syndrome primarily affects the kidneys, ears, and eyes, and does not present with recurrent pseudomonal infections or steatorrhea.
*Trinucleotide repeat expansion of CAG on chromosome 4*
- This genetic defect is responsible for **Huntington's disease**, which is an **autosomal dominant** neurodegenerative disorder.
- Huntington's disease presents with chorea, cognitive decline, and psychiatric symptoms, which are distinct from CF.
*Mutated gene for mitochondrial-tRNA-Lys*
- A mutated gene for mitochondrial-tRNA-Lys is associated with **MELAS syndrome (Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes)**, which is inherited through **maternal (mitochondrial)** inheritance.
- This mode of inheritance is distinct from the autosomal recessive pattern seen in cystic fibrosis.
*Inability to convert carbamoyl phosphate and ornithine into citrulline*
- This describes a defect in **ornithine transcarbamylase (OTC) deficiency**, an **X-linked recessive** disorder, not autosomal recessive.
- OTC deficiency leads to hyperammonemia and metabolic disturbances, without the pulmonary and gastrointestinal symptoms typical of cystic fibrosis.
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