Amino Acid deficiencies

Question 1

Cystinuria

Answer 1

Defect in transporter for uptake of cystine and other dibasic amino acids such as arginine, lysine, and ornithine. COAL
renal colic

Question 2

Hartnup disease

Answer 2

defect in a transporter for nonpolar or neutral amino acid e.g. W
leads to concentrated levels in the urine. located in the kidney and small intestine
FTT, nystagmus, tremor, intermittent ataxia, and photsensitivity

Question 3

hyperhomocysteinemia and homocystinuria

Answer 3

vitamin deficiencies (B6, B12, folic acid) or genetic defects in enzymes cause defective metabolism of homocysteine
hyper homocysteinemia is a risk factor in atherosclerotic heart disease and stroke and can result in neuropsychiatric illness

Question 4

Maple syrup urine disease

Answer 4

rare autosomal disease resulting from deficient branched-chain alpha-keto acid dehydrogenase complex (BCKD) activity which resuts in branched chain ketoaciduria
maple syrup smelling urine and VIL accumulates in blood causing toxic effects on brain function and eventually mental retardation

Question 5

Phenylketonuria (PKU)

Answer 5

Defects in the activity of phenylalanine hydroxyase (PAH). Phe can’t convert to tyrosine so it converts to phenylpyruvate and then to phenylacetate which causes brain damage (myelin formation)

Question 6

Albinism

Answer 6

sever lack of melanin due to defects in tyrosinase causing conversion of tyrosine to melanin be blocked
partial or complete absence of pigmentation in skin, hair, and eyes

Question 7

hyperammonemia

Answer 7

autosomal recessive condition caused by a carbamoyl phosphate synthetase I deficiency

Question 8

Hyper/hypothyroidism

Answer 8

over/underproduction of thyroid hormones T3 and T4

production uses thyroglobulin made by the thyroid consisting of 120 tyrosine residues

Question 9

ammonia toxicity

Answer 9

Excessive ammonia due to disorders in the urea cycle or liver failure can have high toxic effects on the brain and CNS. NH3 is very toxic due to its ability to permeate membranes. Glutamate dehydrogenase catalyzes oxidative deamination of glutamate to a-ketoglutarate (inhibits TCA cycle). PH imbalance, swelling of astrocytes in the brain -> cerebral edema and intracranial hypertension. Depletion of glutamate results in disruption of its neurotransmitter activity.

Question 10

Urea cycle and high protein diet

Answer 10

urea production increased y high protein diet and decreased by high carb diet