Metabolic

Question 1

Phenylketonuria (PKU)

Answer 1

Amino acid/organic acid metabolic disorder
Etiology: Autosomal recessive trait. Elevated levels of phenylalanine.
Signs/symptoms: Symptoms present within a few months after birth. Intellectual and behavioral issues. Gait disturbances, hyperactivity, psychoses, abnormal body odor, lighter colored features.
Treatment: Dietary restriction of phenylalanine throughout life.

Question 2

Tay-Sachs Disease

Answer 2

Lysomal storage disorder
Etiology: Autosomal recessive inherited. Absence or deficiency of hexosaminidase A, causing accumulation of gangliosides (GM2) in brain.
Signs/symptoms: Missed developmental milestones at 6 months of age. Deterioration of motor and cognitive skills. Paralysis. Death by age 5.
Treatment: No effective treatment.

Question 3

Mitochondrial Disorders

Answer 3

Over 100 different forms with different clinical manifestations.
Etiology: Genetically inherited or spontaneous mutations in DNA.
Signs/symptoms: Varies but can include loss of muscle coordination, weakness, visual and hearing problems, learning disabilities, heart, liver, and kidney disease, respiratory, neurological, and GI disorders, and demential.
Treatment: Aimed at alleviating symptoms and slowing progression of disease.

Question 4

Wilson’s Disease

Answer 4

Hepatolenticular degeneration
Etiology: Rare autosomal recessive inherited disorder. Body cannot metabolize copper, which accumulates in brain, liver, cornea, kidney, and other tissue.
Symptoms: Appears in people under 40 and can develop in children between 4-6 yo. Degenerative changes in brain, hepatitis, cirrhosis of liver, athetoid movements, ataxic gait. Emotional and behavioral changes. In later stage, musculoskeletal deformities, fractures, osteomalacia, atrophy, and contractures.
Treatment: Pharmacology to excrete excess copper from body. Treatment of hepatic disease.

Question 5

Metabolic Alkalosis

Answer 5

pH rises above 7.45 due to accumulation of bicarbonate or loss of acids.
Etiology: Continuous vomiting, ingestion of antacids or diuretic therapy. Associated with hypokalemia or nasogastric suctioning.
Signs/symptoms: Nausea, diarrhea, prolonged vomiting, confusion, muscle fasciculations, muscle cramps, neuromuscular hyperexcitability, convulsions, paresthesia, and hypoventilation. Can experience comatose, seizures, and respiratory paralysis of left untreated.
Treatment: Manage underlying cause, correct electrolyte imbalance, administer potassium chloride.

Question 6

Metabolic Acidosis

Answer 6

pH below 7.35 due to accumulation of acids or bicarbonate loss.
Etiology: Occurs with renal failure, lactic acidosis, starvation, diabetic or alcoholic ketoacidosis, severe diarrhea or poisoning by certain toxins.
Signs/symptoms: Hyperventilation, vomiting, diarrhea, headache, weakness and malaise, hyperkalemia, and cardiac arrhythmias. Can induce coma and death of untreated.
Treatment: Manage underlying cause, correct coexisting electrolyte imbalances, and administer sodium bicarbonate.

Question 7

Osteomalacia

Answer 7

Bones become soft due to calcium or phosphorus deficiency. Adequate matrix but insufficient calcification.
Etiology: Calcium lost to inadequate intestinal absorption and phosphorous lost to increase in renal excretion. Also a deficiency in vitamin D.
Signs/symptoms: Aching, fatigue, and weight loss. Myopathy and sensory polyneuropathy may occur along with periarticular tenderness and pain, thoracic kyphosis, bowing of LEs.
Treatment: Increased nutrition and pharmacological intervention, including vitamin D and phosphate supplements.

Question 8

Osteoporosis

Answer 8

Decreased bone mass.
Etiology: Primary osteoporosis includes idiopathic, post-menopausal, or involutional (senile). Secondary includes result of another primary condition or with use of certain medications.
Signs/symptoms: Bone fractures, low thoracic or lumbar pain, loss of lumbar lordosis, kyphosis, decrease in height, dowager’s hump, and postural changes.
Treatment: Vitamin and pharmacological intervention, proper nutrition.

Question 9

Paget’s Disease

Answer 9

Heightened osteoclast activity. Enlarged bone with decreased strength due to high turnover of bone.
Etiology: Genetic and geographical incidence; most commonly affects those over 50 yo.
Signs/symptoms: Musculoskeletal pain, bony deformities. Advanced stages may present with headache, vertigo, hearing loss, mental deterioration, fatigue, increased CO, and heart failure.
Treatment: Pharmacological intervention using bisphosphonates to inhibit bone resorption. Exercise, weight control, and cardiac fitness.