AA Disease

Question 0

What is Hartnup disease?

Answer 0

Neutral amino aciduria. Defective neutral amino acid transporter. Leads to tryptophan in urine. Niacin given to help with pellegra like symptoms (B3)

Question 1

What is Cystinuria?

Answer 1

COAL transporter in lumen (cystine, ornithine, arginine, lysine). Excretion of cystine in urine. Drink lots of water to solubilize cystine

Question 2

Alanine aminotransferase or aspartate aminotransferases in blood (ALT and AST)

Answer 2

Cell damage in liver

Question 3

What is hyperammonemia?

Answer 3

Elevated levels of ammonia often occurring in chronic liver disease or inherited metabolic disorder

Question 4

Ammonia toxicitiy

Answer 4

Depletes alpha ketoglutarate, ATP and NAD(P) via glutamate dehydrogenase. Glutamate is also an excitatory NT.

Question 5

What are two diseases leading to hyperammonemia?

Answer 5

N-acetylglutamate synthase (NAGS) deficiency and CPS I deficiency

Question 6

What is ornitine transcarabmoylase (OTC) defiency

Answer 6

Most common urea cycle disorder, linked to X-chromosome. Increased orotic acid and uracil in blood and urine

Question 7

What is citrullinemia?

Answer 7

Caused by arginiosuccinate synthetase deficiency. A distal urea disorder, not severe as Citrulline can be excreted

Question 8

What is arginiosuccinic aciduria (ASA)?

Answer 8

Argininosuccinate lyase is deficient. Not a problem because argnininosuccinate can be excreted

Question 9

What is argininemia?

Answer 9

Arginase deficiency. Arginine can be excreted. Extremely rare but can lead to developmental abnormality

Question 10

Assay citrulline. Absent or trace. Low orotic acid. What’s wrong?

Answer 10

CPS I or NAGS deficiency

Question 11

Assay Citrulline. Absent or trace. High urine orotic acid. What diagnosis?

Answer 11

OTC deficiency

Question 12

Assay citrulline. 100-300 uM. High levels of plasma arginosuccinate. What’s wrong?

Answer 12

AL deficiency

Question 13

Assay citrulline. Very high levels of citrulline. What’s diagnosis?

Answer 13

AS deficency.

Question 14

What is nonketotic hyperglycinema?

Answer 14

Defect in glycine cleavage complex (glycine synthase) preventing production of ammonia and carbon dioxide. High glycine in blood.

Question 15

What is histidinemia?

Answer 15

Deficiency in histidase. High levels in blood and urine of histidine.

Question 16

What is maple syrup urine disease?

Answer 16

Defective or missing branched-chain alpha-keto acid dehydrogenase

Question 17

What is tyrosinemia II?

Answer 17

Missing tyrosine aminotransferase (important in the process of making fumarate and acetoacetate from phenylalanine/tyrosine). Accumulation of tyrosine

Question 18

What is tyrosinema I?

Answer 18

Defect in fumarate and acetoacetate steps of trp/phe degredation. Leads to liver and renal disease. Not associated with as significant of a tyrosine build up

Question 19

What is alcaptonuria?

Answer 19

Absence of homogentisate oxidase which leads to accumulation of homogentisate in urine. Leads to dark urine and arthritis.

Question 20

What is albinism?

Answer 20

Defect in tyrosine metabolism leading to deficient melanin production.

Question 21

What is phenylketonuria?

Answer 21

Defect in phenylalanine conversion to tyrosine conversion perhaps in phenylalanine hydroxylase

Question 22

What are two potential causes of phenylketonuria?

Answer 22

Deficiency of phenylalanine hydroxylase (classical) or defect in tetrahydrobiopterin (BH4, also referred to as biopterin) cofactor synthesis (non-classical)

Question 23

Non-classical PKU (i.e. BH4 issues) is determined by what as compared to classical PKU?

Answer 23

Dopamine levels (catecholamines and serotonin levels) are decreased

Question 24

What is homocystinuria?

Answer 24

High levels of homocysteine in plasma/serum due to cystathionine synthase deficiency or reduced affinity for B6 cofactor. Could also be due to remethylation pathway deficiency (methionine synthase). B6,B12, and Folate help (THF is involved in methionine recovery).

Question 25

What is methylmalonic acedemia (MMA)?

Answer 25

Deficiency in methylmalonyl CoA mutase which leads to accumulation of methylmalonic acid. Accumulation from met, val, Ile, and Thr

Question 26

4 causes for homocystinuria

Answer 26

Cystathionine synthase deficiency. Loss of pyridoxal phosphate. methionine synthase def. defin methylene THF reductase

Question 27

Folic acid deficiency

Answer 27

Hematopoietic and neurological symptoms

Question 28

What is pernicious anemia?

Answer 28

Could be because of intrinsic factors or B12. Lead to megaloblastic anemia or neurological defect.

Question 29

What is neuropsychiatric porphyria?

Answer 29

Accumulation of ALA and PBG in cells.

Question 30

What is cutaneous porphyria?

Answer 30

Accumulation of porphyriogens in skin and tissues leading to photosensitivity.

Question 31

What is acute intermittent porphyria (AIP)?

Answer 31

PBG and ALA in the urine. Caused by deficiency in PBG demainase (catalyzes porphobilinogen to hydroxymethylbilane)

Question 32

What is porphyria cutaneous tarda (PCT)?

Answer 32

Defect in uroporphyrinogen decarboxylase which converts uroporphyrinogen III to coproporphyrinogen III. Accumulation leads to photosensitivity.

Question 33

What is jaundice?

Answer 33

Accumulation of bilirubin (hyperbilirubinemia). Caused by excess production or decreased excretion.

Question 34

What are the three types of jaundice?

Answer 34

Hemolytic or preheptic jaundice (production exceeds liver conjugation capacity). Hepatocellular or intrehepatic jaundice (liver damage). Obstructive or Posthepatic jaundice (decreased secretion).

Question 35

What is neonatal jaundice?

Answer 35

Liver not fully developed