Amino Acid Disorders

Question 1

PKU enzyme

Answer 1

phenylalanine hydroxylase

Question 2

dark connective tissue, brown pigmented sclerae

Answer 2

alkaptonuria

Question 3

Becomes essential amino acid in PKU

Answer 3

tyrosine needs to be supplemented due to no conversion from phenylalanine

Question 4

Build up in PKU

Answer 4

phenylalanine

Question 5

Homocystinuria enzyme

Answer 5

cystathionine synthase deficiency

Question 6

Deficiency of tyrosinase

Answer 6

albinism

Question 7

Pigment-forming molecule in alkaptonuria

Answer 7

homogentisic acid

Question 8

Sweetener to avoid in PKU

Answer 8

aspartame

Question 9

Maternal PKU features

Answer 9

microceph and intellectual disability
growth retardation
congenital heart defects

lack of PKU therapy during pregnancy (phenylalanine and phenylketone build up is toxic to fetus)

Question 10

ochronosis

Answer 10

alkaptonuria

Question 11

enzyme in alkaptonuria

Answer 11

homogentisic acid oxidase

Question 12

Features of PKU

Answer 12

growth/mental retardation
seizures
fair skin (no tyrosine --> melanin)
eczema
musty body odor

Question 13

cystathione synthase deficiency

Answer 13

Homocystinuria

Question 14

PKU cofactor

Answer 14

BH4 or tetrahydrobiopterin

Question 15

musty body odor

Answer 15

PKU

Question 16

urine turns black with prolonged air exposure

Answer 16

alkaptonuria

Question 17

Decreased affinity of pyridoxal phosphate to cystathionine synthase

Answer 17

Homocystinuria

enzyme requires B6

Question 18

Homocysteine methyltransferase

Answer 18

Homocystinuria

Question 19

homogentisic acid is toxic to:

Answer 19

cartilage

causes arthralgia in alkaptonuria

Question 20

Neurotoxic effects in PKU due to

Answer 20

phenylalanine

Question 21

Marfanoid habitus, lens subluxation, mental retardation

Answer 21

homocystinuria

Question 22

Hereditary defect of renal PCT and intestinal amino acid transporter

Answer 22

cystinuria

Question 23

in cystinuria, what amino acids are affected? How?

Answer 23

Prevents reabsorption of COLA
Cysteine
Ornithine
Lysine
Arginine

Question 24

Main complication of cystinuria

Answer 24

cystine kidney stones

Question 25

Treatment of cystinuria:

Answer 25

acetazolamide (alkalinization of urine)