Endocrine Questions

Question 1

What is the primary end-product that becomes toxic in urea cycle disorders?**
- A) Uric acid
- B) Lactic acid
- C) Ammonia
- D) Carbon dioxide

Answer 1

Answer:** C) Ammonia

Question 2

Which clinical finding is not commonly associated with hyperammonemia in urea cycle disorders?**
- A) Vomiting
- B) Lethargy
- C) Excessive salivation
- D) Seizures

Answer 2

*Answer:** C) Excessive salivation

Question 3

What level of ammonia is typically seen in urea cycle disorders to suggest hyperammonemia?**
- A) > 50 mmol/L
- B) > 100 mmol/L
- C) > 200 mmol/L
- D) > 300 mmol/L

Answer 3

Answer:** B) > 100 mmol/L

Question 4

What is the initial treatment focus in the acute management of urea cycle disorders?**
- A) Increase protein intake
- B) Establishing a source of glucose and rapidly decreasing ammonia levels
- C) Providing ketone supplements
- D) Restricting fluid intake

Answer 4

*Answer:** B) Establishing a source of glucose and rapidly decreasing ammonia levels

Question 5

Which enzyme defect consequence is associated with urea cycle disorders?**
- A) Elevated blood urea nitrogen (BUN)
- B) Inability to detoxify waste nitrogen leading to hyperammonemia
- C) Decreased urine output
- D) Rapid increase in white blood cell count

Answer 5

*Answer:** B) Inability to detoxify waste nitrogen leading to hyperammonemia

Question 6

Which specialist is typically consulted for the management of urea cycle disorders?**
- A) Pediatric endocrinologist
- B) Cardiologist
- C) Neurologist
- D) Geneticist

Answer 6

Answer: A) Pediatric endocrinologist

Question 7

What dietary change is recommended for the chronic management of urea cycle disorders?**
- A) Increase in carbohydrate intake
- B) Reduction in protein consumption
- C) Increase in fat intake
- D) Increase in vitamin supplements

Answer 7

Answer:** B) Reduction in protein consumption

Question 8

What can be a long-term complication of urea cycle disorders if not properly managed?**
- A) Diabetes mellitus
- B) Mental retardation
- C) Osteoporosis
- D) Hypertension

Answer 8

*Answer:** B) Mental retardation

Question 9

Emily is a 6-month-old infant who presented to the pediatric emergency department with vomiting and lethargy. Her parents noted that symptoms started after they introduced her to protein-rich baby food. On examination, Emily is irritable and exhibits signs of confusion.

Questions:

1. What condition should be considered given Emily’s symptoms following protein ingestion?

Answer 9

Answer: Urea cycle disorder should be considered given her symptoms following protein ingestion, particularly hyperammonemia.

Question 10

Emily is a 6-month-old infant who presented to the pediatric emergency department with vomiting and lethargy. Her parents noted that symptoms started after they introduced her to protein-rich baby food. On examination, Emily is irritable and exhibits signs of confusion

Which laboratory test could help in confirming the suspected diagnosis (dx urea cycle disorder)?

Answer 10

Answer: A serum ammonia level should be checked. An ammonia level >100 mmol/L would be strongly indicative of a urea cycle disorder.

Question 11

What immediate management step should be taken to address her condition?** (urea cycle disorder)

What specialist referral would be beneficial for Emily?**

Answer 11

Answer: Acute care should focus on establishing a source of glucose and rapidly decreasing ammonia levels.

Answer: A referral to a pediatric endocrinologist would be beneficial.

Question 12

ohn is a 10-year-old boy who has had several episodes of confusion, irritability, and seizures following meals. He has been previously healthy, but these symptoms appeared after starting a high-protein diet. Blood tests show low BUN levels and an elevated ammonia concentration.

Questions:

1. What is the likely metabolic disorder affecting John?

Answer 12

Answer: John likely has a urea cycle disorder, resulting in hyperammonemia.

Question 13

What dietary modification should be recommended for John as part of his chronic management?** (urea cycle disorder)

Answer 13

Answer: John should have a reduction in protein consumption as part of his chronic management.

Question 14

What are potential long-term complications if this condition is not properly managed?* (urea cycle disorder)

Answer 14

Answer: Potential long-term complications include metabolic decompensation, mental retardation, and possibly death

Question 15

What diagnostic studies could further support the diagnosis of a urea cycle disorder in John?**

Answer 15

Answer: Enzyme assays and genetic mutation analysis could further support the diagnosis.

Question 16

Sarah, an 8-year-old, is brought to the clinic with a history of episodic vomiting, confusion, and lethargy over the past month. These symptoms exacerbate after she consumes foods rich in protein. Her BUN is noted to be low, while her ammonia level is reported at 120 mmol/L.

Questions:

1. What does the elevated ammonia level indicate in Sarah’s case?

Answer 16

Answer: The elevated ammonia level indicates hyperammonemia, commonly seen in urea cycle disorders.

Question 17

Why might Sarah have a low BUN result?** (urea cycle disorder)

Answer 17

Answer: A low BUN result may occur because the urea cycle is disrupted, leading to accumulation of ammonia rather than conversion to urea.

Question 18

What is an essential component of acute care management for Sarah?* (urea cycle disorder)

Answer 18

Answer: An essential component is to rapidly decrease ammonia levels and establish a source of glucose.

Question 19

Considering long-term treatment, why is it important for Sarah to avoid high-protein meals?** (urea cycle disorder)

Answer 19

Answer: It is important because protein intake increases ammonia production, exacerbating symptoms in urea cycle disorders.

Question 20

Phenylketonuria (PKU) is caused by a deficiency of which enzyme?**

A) Tyrosine hydroxylase
B) Phenylalanine hydroxylase
C) Cystathionine synthase
D) Methionine adenosyltransferase

Answer 20

Answer:* B) Phenylalanine hydroxylase

Question 21

What are common clinical findings in untreated individuals with PKU?**

A) Growth retardation, cardiac anomalies, blindness
B) Lighter skin/hair, eczematous rash, mousy odor
C) Darkened skin, thick hair, hyperactivity
D) Bruising easily, frequent infections, jaundice

Answer 21

Answer: B) Lighter skin/hair, eczematous rash, mousy odor

Question 22

Which dietary component should be limited in individuals with PKU?**

A) Galactose
B) Methionine
C) Phenylalanine
D) Leucine

Answer 22

Answer:* C) Phenylalanine

Question 23

Homocystinuria is primarily due to a deficiency in which enzyme?**

A) Phenylalanine hydroxylase
B) Tyrosine aminotransferase
C) Cystathionine synthase
D) Aspartate transaminase

Answer 23

Answer:* C) Cystathionine synthase

Question 24

What is a notable risk for individuals with untreated homocystinuria?**

A) Anemia and immunodeficiency
B) Progressive blindness and deafness
C) Ocular lens dislocation and thromboembolic events
D) Liver failure and renal calciuli

Answer 24

Answer:* C) Ocular lens dislocation and thromboembolic events

Question 25

Which vitamin may benefit some children with homocystinuria?**

A) Vitamin C
B) Vitamin E
C) Vitamin B6
D) Vitamin K

Answer 25

Answer: C) Vitamin B6

Question 26

In which screening method is PKU typically diagnosed?**

A) Genomic DNA sequencing
B) Newborn screening
C) Serological testing postnatally
D) MRI imaging at birth

Answer 26

Answer:* B) Newborn screening

Question 27

What is the target range for serum phenylalanine levels in PKU management?**

A) 60-120 mmol/L
B) 100-200 mmol/L
C) 120-360 mmol/L
D) 250-500 mmol/L

Answer 27

Answer:* C) 120-360 mmol/L

Question 28

Why is strict dietary control essential for pregnant women with PKU?**

A) To ensure cardiac health
B) To prevent birth defects in the offspring
C) To minimize nausea and vomiting
D) To enhance muscle growth in the infant

Answer 28

Answer:* B) To prevent birth defects in the offspring

Question 29

Elevated levels of which amino acid would indicate potential homocystinuria in newborn screening?**

A) Tyrosine
B) Methionine
C) Leucine
D) Glutamine

Answer 29

Answer:* B) Methionine

Question 30

Age: 3 Weeks
- Ethnicity: Caucasian

Clinical Presentation:
Emma was born following an uncomplicated pregnancy and birth, showing no abnormalities or symptoms at birth. At her routine newborn screening, her results returned positive for elevated phenylalanine levels. Emma is otherwise healthy and developing appropriately for her age.

Questions:
1. What is the most likely diagnosis?
2. What enzyme deficiency is responsible for her condition?
3. What management strategies should be employed for Emma moving forward?

Answer 30

The most likely diagnosis is Phenylketonuria (PKU).

2. PKU is caused by a deficiency of the enzyme phenylalanine hydroxylase, which leads to elevated levels of phenylalanine in the body.
3. Management strategies include:
   • Limiting dietary intake of phenylalanine to keep serum levels between 120-360 mmol/L.
   • Using a modified formula specially designed for babies with PKU containing low phenylalanine content.
   • Ensuring Emma has a life-long restricted diet in terms of phenylalanine content to avoid CNS damage and developmental issues.
   • Regular consultations with a dietician to support the family’s adherence to dietary changes.
   • Monitoring closely in case of future pregnancies as strict control of phenylalanine levels is essential for maternal PKU cases.

Explanation:**
PKU is an autosomal recessive disorder more common in Caucasians. If untreated, it can cause significant developmental issues, but it is readily managed with dietary adjustments. Initial detection is typically done through newborn screening.

Question 31

Name: Aiden
- Age: 5 Years
- Presenting Concern: Developmental delay

Clinical Presentation:
Aiden’s parents are concerned because he is not reaching developmental milestones in line with his peers. His medical history reveals nonspecific failure to thrive and progressive myopia. Recent tests show elevated levels of methionine and total homocystine in his blood work.

Questions:
1. What is the most likely diagnosis?
2. What enzyme deficiency is responsible for Aiden’s condition?
3. What complications can arise if his condition remains untreated?
4. What treatment options should be considered?

Answer 31

he most likely diagnosis is Homocystinuria.

2. Homocystinuria is caused by a deficiency of the enzyme cystathionine synthase.
3. If untreated, Aiden might experience severe complications such as:
   
   • Ocular lens dislocation leading to visual problems.
   • Progressive mental retardation.
   • Thromboembolic events, increasing the risk of strokes.
   • Possible convulsions or seizures.
4. Treatment options include:
   
   • Administration of Vitamin B6, which may help reduce homocystine levels in some children.
   • Regular monitoring of homocystine and methionine levels.
   • Implementing a low-methionine diet with supplements such as betaine as necessary to manage symptoms and reduce the risk of complications.
   • Regular consultation with neurology and ophthalmology for symptom management and monitoring.

Homocystinuria is an autosomal recessive disorder that affects amino acid metabolism, resulting in increased levels of homocystine. Treatment focuses on dietary management and supplementation to mitigate symptoms and potential complications.

Question 32

What enzyme deficiency causes PKU?**
- A) Tyrosinase
- B) Phenylalanine hydroxylase
- C) Cystathionine synthase
- D) Methionine adenosyltransferase

Answer 32

Answer:** B) Phenylalanine hydroxylase

Question 33

Which of the following is a common symptom if PKU is untreated?**
- A) Darker skin and hair
- B) Ocular lens dislocation
- C) Eczematous rash
- D) Hyperactivity

Answer 33

Answer:** C) Eczematous rash

Question 34

PKU is more prevalent in which ethnic group?**
- A) African Americans
- B) Asians
- C) Caucasians
- D) Hispanics

Answer 34

Answer:** C) Caucasians

Question 35

What is the goal serum phenylalanine range in the management of PKU?**
- A) 50-100 mmol/L
- B) 120-360 mmol/L
- C) 400-500 mmol/L
- D) 600-700 mmol/L

Answer 35

Answer:** B) 120-360 mmol/L

Question 36

What is a notable skin/hair characteristic in untreated PKU?**
- A) Darker skin/hair
- B) Lighter skin/hair
- C) Red skin/hair
- D) Normal skin/hair

Answer 36

Answer:** B) Lighter skin/hair

Question 37

What odor is associated with untreated PKU?**
- A) Fruity odor
- B) Musty/mousy odor
- C) Pungent odor
- D) No odor

Answer 37

Answer:** B) Musty/mousy odor

Question 38

For patients with PKU, why must pregnant women maintain strict control of their phenylalanine levels?**
- A) To prevent gestational diabetes
- B) To avoid birth defects in their child
- C) To reduce weight gain
- D) To increase milk production

Answer 38

*Answer:** B) To avoid birth defects in their child

Question 39

Diagnosis of PKU in newborns typically relies on what method?**
- A) Visual observation
- B) Genetic testing at birth
- C) Newborn screening
- D) Dietary history

Answer 39

Answer: C) Newborn screening

Question 40

Which diet component is significant in PKU management?**
- A) High protein intake
- B) Limited phenylalanine intake
- C) Increased sugar intake
- D) Unlimited fat intake

Answer 40

*Answer:** B) Limited phenylalanine intake

Question 41

What is the inheritance pattern of PKU?**
- A) Autosomal dominant
- B) Autosomal recessive
- C) X-linked recessive
- D) X-linked dominant

Answer 41

Answer: B) Autosomal recessive

Question 42

Which artificial sweetener should be monitored in PKU patients due to its phenylalanine content?**
- A) Saccharin
- B) Aspartame
- C) Stevia
- D) Xylitol

Answer 42

Answer:** B) Aspartame

Question 43

What neurotransmitter synthesis is impaired in PKU?**
- A) Serotonin
- B) Dopamine
- C) Histamine
- D) Acetylcholine

Answer 43

*Answer:** B) Dopamine

Question 44

What enzyme deficiency is primarily associated with Homocystinuria?**
- A) Phenylalanine hydroxylase
- B) Homogentisate oxidase
- C) Cystathionine synthase
- D) Tyrosinase

Answer 44

*Answer:** C) Cystathionine synthase

Question 45

An elevated level of what amino acid is a diagnostic indicator of Homocystinuria?**
- A) Phenylalanine
- B) Methionine
- C) Tyrosine
- D) Glutamine

Answer 45

Answer:** B) Methionine

Question 46

What is a potential serious complication of untreated Homocystinuria?**
- A) Progressive mental retardation
- B) Skin rash
- C) Loss of appetite
- D) Increased muscle tone

Answer 46

Answer: A) Progressive mental retardation

Question 47

Which vitamin can be useful in treating some cases of Homocystinuria?**
- A) Vitamin B1
- B) Folic acid
- C) Vitamin B6
- D) Calcium

Answer 47

*Answer:** C) Vitamin B6

Question 48

Which ocular condition is associated with untreated Homocystinuria?**
- A) Cataracts
- B) Ocular lens dislocation
- C) Glaucoma
- D) Night blindness

Answer 48

Answer:** B) Ocular lens dislocation

Question 49

What is a common risk in patients with untreated Homocystinuria that requires monitoring?**
- A) Osteoporosis
- B) Metabolic stroke
- C) High blood pressure
- D) Sleep apnea

Answer 49

Answer: B) Metabolic stroke

Question 50

*How is Homocystinuria inherited?**
- A) Autosomal dominant
- B) Autosomal recessive
- C) X-linked recessive
- D) Mitochondrial

Answer 50

Answer:** B) Autosomal recessive

Question 51

What compound levels must be frequently monitored in Homocystinuria management?**
- A) Urea and creatinine
- B) Glucose and lactose
- C) Homocystine and methionine
- D) Calcium and phosphate

Answer 51

Answer:** C) Homocystine and methionine

Question 52

What is a non-specific early sign of Homocystinuria in infants?**
- A) Severe cough
- B) Failure to thrive
- C) High fever
- D) Diarrhea

Answer 52

*Answer:** B) Failure to thrive

Question 53

In addition to vitamin supplementation, what other nutritional intervention is suggested for Homocystinuria?**
- A) High protein diet
- B) High methionine diet
- C) Low methionine diet
- D) High fat diet

Answer 53

Answer:** C) Low methionine diet

Question 54

What is Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) primarily associated with?**

A) Enhanced production of ketones

B) Inability to metabolize medium-chain fatty acids

C) Excessive fasting tolerance

D) Overproduction of bile acids

Answer 54

Answer: B) Inability to metabolize medium-chain fatty acids

Question 55

What is a common management strategy for Medium-chain acyl-CoA dehydrogenase deficiency?**

A) Increased fasting periods

B) High-carbohydrate diet

C) Carnitine supplementation and avoidance of fasting

D) Increased protein intake

Answer 55

Answer: C) Carnitine supplementation and avoidance of fasting

Question 56

What type of accumulation characterizes lysosomal disorders?**

A) Ketone bodies

B) Glycoproteins, glycolipids, or glycosaminoglycans

C) Free fatty acids

D) Amino acids

Answer 56

Answer: B) Glycoproteins, glycolipids, or glycosaminoglycans

Question 57

Which of the following is a clinical finding associated with dyslipidemia in children?**

A) Energetic and high endurance levels

B) Xanthomas and arcus corneae

C) Hyperglycemia

D) Low blood pressure

Answer 57

Answer: B) Xanthomas and arcus corneae*

Question 58

What lifestyle changes are recommended for managing dyslipidemia?**

A) Increasing sugar intake and reducing physical activity

B) Dietary changes and regular exercise

C) Excessive fasting

D) High fat diet and low protein intake

Answer 58

Answer: B) Dietary changes and regular exercise

Question 59

At what age range is universal cholesterol screening recommended for children?**

A) 3-5 years

B) 9-11 years

C) 15-17 years

D) 12-14 years

Answer 59

Answer: B) 9-11 years*

Question 60

What is the primary cause of familial hypercholesterolemia?**

A) Pathologic mutation in apolipoprotein E

B) Pathologic mutation in LDL receptor

C) Overproduction of HDL

D) Deficiency in triglycerides

Answer 60

Answer: B) Pathologic mutation in LDL receptor

Question 61

hich of the following is not a possible secondary cause of dyslipidemia?**

A) Obesity

B) Obstructive liver disease

C) Genetic mutations of HDL receptors

D) Alcohol consumption

Answer 61

Answer: C) Genetic mutations of HDL receptors (This is not usually considered a secondary cause.)*

Question 62

Name:** Baby A
- Age: 11 months
- Gender: Female
- Medical History: Previously healthy, born with normal weight and development, now experiencing lethargy and decreased intake due to a recent infection.

Clinical Presentation:
Baby A presents to the emergency department with lethargy, rapid breathing, and refusal to breastfeed, following 24 hours of decreased oral intake after a gastroenteritis episode.

Clinical Examination and Investigations:
- Vital Signs: Tachycardia, tachypnea, hypotension
- Neurological Findings: Lethargy, hypotonia
- Laboratory Results:
- Hypoglycemia
- Metabolic acidosis
- Elevated medium-chain acylcarnitines on plasma acylcarnitine profile
- Genetic Testing: Positive for MCADD mutation

Answer 62

What is the probable cause of Baby A’s current symptoms?**
- The symptoms are likely due to a metabolic crisis caused by medium-chain acyl-CoA dehydrogenase deficiency (MCADD), which impairs her ability to utilize medium-chain fatty acids for energy during fasting or illness.

2. How does MCADD affect metabolic processes in fasting states?
   
   • MCADD affects the oxidation of medium-chain fatty acids. Without this process, the body cannot generate ketones for energy during fasting or illness, leading to hypoglycemia and a metabolic crisis.
3. What immediate treatment should be initiated upon recognizing this condition?
   
   • Intravenous glucose should be administered immediately to treat hypoglycemia and provide energy until normal feeding can be resumed.
     Why is frequent feeding crucial for managing MCADD, particularly in infants like Baby A?**
   • Frequent feeding prevents fasting-induced metabolic crises by ensuring a continuous supply of glucose, reducing the dependency on fatty acid oxidation for energy.
4. How can parents help manage Baby A’s condition to prevent future crises?
   
   • Parents should ensure Baby A feeds every 3-4 hours and avoid prolonged fasting, educate themselves on early signs of metabolic crises, and maintain routine follow-ups with healthcare providers.
5. What role does genetic counseling play for Baby A’s family in the context of MCADD?
   
   • Genetic counseling can provide the family with information regarding the inheritance pattern of MCADD, implications for future siblings, and advise on family planning to manage risk.