Hereditary disorders of amino acid metabolism/Questions and case studies

Questions

 * 1) which amino acids are mostly taken up by the kidneys?
 * 2) *A – glycine
 * 3) *B – arginine
 * 4) *C – alanine
 * 5) *D – glutamic acid
 * 6) *E – glutamine
 * 7) *F – leucine
 * 8) *G – histidine
 * 9) *H – tyrosine
 * 10) Which amino acids does the muscle release into the bloodstream in the greatest amount?
 * 11) *A – glycine
 * 12) *B – arginine
 * 13) *C – alanine
 * 14) *D – glutamic acid
 * 15) *E – glutamine
 * 16) *F – leucine
 * 17) *G – histidine
 * 18) *H – tyrosine
 * 19) which Enzyme defects in the cycle of urea formation lead to disorders of brain function. What is it caused by?
 * 20) *A – Hyperamonemia
 * 21) *B – Formation of atypical amino acids
 * 22) *C – Increased formation of biogenic amines
 * 23) *D – Hyperuricemia
 * 24) *E – Hypeoglycemia (gluconeogenesis from amino acids is reduced)
 * 25) Which amino acids are not nutritionally essential?
 * 26) *A – Methionine
 * 27) *B – Fenylalanine
 * 28) *C – Cysteine
 * 29) *D – Tyrosine
 * 30) *E – Leucine
 * 31) *F – Isoleucine
 * 32) *G – Valine
 * 33) *H – Threonine
 * 34) Which amino acids are not glucogenic?
 * 35) *A – Isoleucine
 * 36) *B – Leucine
 * 37) *C – Histidine
 * 38) *D – Cystine
 * 39) *E – Lysine
 * 40) *F – Valine
 * 41) *G – Tryptophan
 * 42) Tyrosine is a precursor for the synthesis of:
 * 43) *A – Noradrenalinu
 * 44) *B – Adrenalinu
 * 45) *C – Melaninu
 * 46) *D – DOPA
 * 47) The key intermediate metabolite for cysteine ​​synthesis in the liver is::
 * 48) * A – Argininosuccinate
 * 49) * B – Homoserine
 * 50) * C – Glutamic acid semialdehyde
 * 51) * D – Cystathionine
 * 52) * E – Xanthurenic acid
 * 53) The mechanism of creatinine excretion by the kidneys is:
 * 54) *A – In glomerular filtration (no tubular secretion or tubular reabsorption)
 * 55) *B – In glomerular filtration and in a small proportion of tubular secretion
 * 56) *C – In glomerular filtration and tubular reabsorption
 * 57) *D – In tubular secretion
 * 58) In prerenal uremia it is
 * 59) *A – Increased creatinine proportional to increased urea
 * 60) *B – Elevated urea and creatinine at the upper limit of normal
 * 61) *C – Elevated creatinine and urea at the upper limit of normal
 * 62) *D – Creatinine and urea only at the upper limit of normal.


 * }

Infant with psychomotor retardation
Infant, 3 and 1/2 months, normal delivery. After several weeks, the mother observed that the child (compared to his siblings) showed little interest in the surroundings and that he was not making progress. The urine in the diapers had a strange smell, like mice. The girl also developed tremors in her limbs. In the laboratory, a positive Guthrie's test for hyperphenylalaninemia was demonstrated, the urine gave a positive reaction with ferric chloride for phenylpyruvic acid. Phenylalanine concentration in plasma: 1089 mol/l (N:  109 mol/l). Examination of the biopsy specimen of the liver showed a significant reduction (to 1%) of phenylalanine hydroxylase. This indicates the presence of the "classic" form of phenylketonuria

Questions:
 * 1) why can't the presence of phenylalanine in food be completely excluded in the dietary treatment of phenylketonuria?
 * 2) What may be at risk for the fetus of a pregnant woman with phenylketonuria (who has not inherited this disorder)
 * 3) Can the organism of a patient with phenylalanine hydroxylase deficiency form tyrosine?

A patient with dislocation of the eye lens and mild retardation with a convulsive attack
A boy, 15 years old, had a sudden seizure resembling a "grand-mal". The doctor found muscle weakness on the left face and on the left upper and lower limbs, and therefore sent the boy to the hospital with a diagnosis of cerebrovascular accident (right hemisphere). Here he was examined in more detail and the history of surgery (iridectomy) of both eye lenses due to their large dislocation was found. The boy was slightly mentally retarded. These data led to a more detailed examination of sulfur-containing amino acids. The findings confirmed the diagnosis of homocystinuria: serum total homocyst(e)in – 965 μmol/l (N: < 30), cysteine ​​unmeasurable, folate and B12 normal.

Questions:
 * 1) Which enzyme is deficient in this disease and what changes in amino acid metabolism does it lead to?
 * 2) Can elevated levels of homocyst(e)in and homocystinuria also be caused by diet?
 * 3) Elevated level of homocysteine ​​is a risk factor. For which states?

A patient with renal colic
A boy, 16 years old, was hospitalized for severe pain in the left side radiating to the pubic area. He had red-brown urine and marked erythrocyturia in the urinary sediment, and after acidifying the urine with acetic acid, flat transparent hexagonal crystals were found in the sediment. Imaging techniques found stones in both kidneys.

Questions:
 * 1) What urinary calculus comes into consideration here?
 * 2) What disorder (deficiency) is the essence of hereditary cystinuria?
 * 3) How can you prevent or at least reduce the formation of cystine stones?
 * 4) What is the difference between cystinuria and cystinosis?

Related articles

 * Hereditary disorders of amino acid metabolism
 * Disorders of ureagenesis

Source

 * MASOPUST, Jaroslav a Richard PRŮŠA. Patobiochemie metabolických drah. 1. vydání. Praha : Univerzita Karlova, 1999. 182 s. s. 50- 54.  ISBN 80-238-4589-6.