Amino Acid Disorders Flashcards Preview

STEP1 > Amino Acid Disorders > Flashcards

Flashcards in Amino Acid Disorders Deck (15):
1

What is a weird thing that patients with PKU have to stay away from?

aspartame, artificial sweetener

2

What are the symptoms of PKU?

ID
growth retardation
seizures
fair skin
eczema
musty body odor

3

What are the findings in the baby of a mom w/ PKU who doesn't manage her diet during pregnancy?

microcephaly
ID
growth retardation
congenital heart defects

4

HOw is maple syrup urine disease inherited? What is the defect?

autosomal recessive
defective alpha ketoacid dehydrogenase (can't break down branched AA)
get buildup of isoleucine, leucine, valine
I Love Vermont Maple Syrup from maple trees (branched)

5

What are the symptoms of maple syrup urine disease?

sweet smelling urine
CNS defects, ID
death

6

What is the defect in alkaptonuria?

aka ochronosis
deficiency of homogentisate oxidase
can't convert tyrosine-->homogentisic acid-->(homogentisic oxidase)-->maleylacetoacetic acid-->fumarate-->TCA

7

What is the inheritance of alkaptonuria? What are the symptoms?

autosomal recessive
darkly pigmented
dark CT, brown sclera, urine turns black when exposed to air
arthralgias
Think Al Capone in Dark Suit

8

What is the treatment for alkaptonuria?

Vit C, avoid phenylalanine, tyrosine

9

Describe the pathways that start w/ homocysteine.

#1: homocysteine-->methionine via homocysteine methyltransferase, B12. Methionine-->SAM
#2: homocysteine-->cystathione via cystathione synthase, B6, serine. Cystathione-->Cysteine

10

What is required to make SAM?

Methionine
ATP
THF
B12

11

What is the inheritance pattern of all types of homocysteinuria?

aut recessive

12

What are the findings in homocysteinuria?

increased homocysteine in urine
ID
osteoporosis
kyphosis
tall
lens subluxation (downward)
thrombosis, atherosclerosis

13

Aside from homocysteinuria, what other condition has lens subluxation? Which direction?

Marfan--subluxation of lens upward. Pompous Michael Phelps.
Homocysteinuria--subluxation downward. Humble.

14

What defect leads to cystinuria? Inheritance?

autosomal recessive
COLA. defect in renal PCT and intestinal AA transporters to absorb cysteine, ornithine, lysine, arginine.

15

What is the diagnostic test for cystinuria? Finding? Main treatment?

diagnosis: urinary cyanide-nitroprusside test
hexagonal cysteine kidney stones
acetazolamide, alkalization of the urine