S2 E090 Metabolic Disorders and a new format

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G6PD Deficiency

• X- linked recessive
• More commonly found in
  • Males
  • African Americans
  • Asians
  • Patients of Mediterranean or Middle Eastern decent
• Increases RBC susceptibility to breakdown
  • Specific triggers lead to cellular breakdown
    • Bacterial or viral infection
    • Fava beans which may be found in flour
    • Drugs
      • Aspirin
      • Antimalarials
      • Sulfonamides
      • Methylene blue
  • Diabetic ketoacidosis

Clinical Presentation & Physical Exam Findings

• Jaundice
• Dark urine
• Fatigue

Labs and Studies

• CBC
  • Anemia
  • Elevated retic count
• Peripheral blood smear
  • [[Bite Cells]]
  • [[Heinz Bodies]]
• G6PD assay

Treatment

• Prevention – Avoid triggers
• Supportive care
• Blood transfusion

Paget Disease of the Bone

• A chronic condition that involves accelerated bone turnover with disorganized remodeling
• There is a gradual onset typically affecting adults over age 40
• Most commonly affects the pelvis, femur and skull

Clinical Presentation & Physical Exam Findings

• Pathologic fractures from weakened bones
• Bone pain
• Stiffness
• Fatigue
• Arthritis
• Enlarged bones

Labs and Studies

• X-ray – Paget’s has a distinct appearance
• Blood tests
  • Alkaline phosphatase – elevated
  • Calcium – usually normal
  • Phosphate
• Bone scan
• Bone biopsy

Treatment

• Supportive care
• Bisphosphonates

Phenylketonuria

• Autosomal recessive trait
• Patients produce a low level of the enzyme that breaks down phenylalanine which can lead to toxic levels of this amino acid.
• Infants have no symptoms initially because the mother is able to break down phenylalanine
• Phenylalanine serum levels are part of newborn screening

Clinical Presentation & Physical Exam Findings

• Hypopigmentation
• Seizures
• Hyperactivity
• Progressive mental impairment leading to missed developmental milestones
• Learning disabilities
• [[Mousy odor]] in urine and sweat

Labs and Studies

• Serum phenylalanine levels taken by heel stick as part of newborn screening

Treatment

• Diet low in phenylalanine

Rickets

• A disease resulting in softening and weakening of the bones
• Typically caused by a vitamin D deficiency

Risk Factors/Causes

• Diet lacking in Vitamin D, calcium or phosphorus
• Low sun exposure
• Dark skin
• Celiac disease

Clinical Presentation & Physical Exam Findings

• Bone tenderness
• Pathologic fractures
• Bowed legs
• Skeletal survey – a complete set of x-rays

Labs and Studies

• Serum calcium – usually low
• Serum phosphorus – usually low
• Vitamin D – low

Treatment

• Sun exposure
• Diet and Supplementation
  • Increase dietary intake of Vitamin D and calcium
  • Supplement Vitamin D and Calcium
• Fava beans are associated with what diagnosis?
  • G6PD deficiency
• What clues for G6PD deficiency might you see on a peripheral blood smear?
  • Heinze bodies
  • Bite Cells
• Paget’s disease of the bone typically affects adults over what age?
  • Older than 40
• A mousy odor should make you think of what diagnosis?
  • Phenylketonuria
• At what age is the screening for phenylketonuria performed?
  • 2-7 days after birth
• Describe the picture of rickets?
  • Low Vitamin D –> Poor bone production –> Soft bones