mito/CDG

Question 1

when should one consider sending a lactate/pyruvate ration?

Answer 1

lactate/pyruvate ration in blood or CSF is only useful when the lactate level is high

Question 2

when is the best time to sample lactate levels

Answer 2

postparandial lactate levels are more sensitive than fasting specimens

and are prefered

Question 3

what is the prefered site for muscle biopsy for mitochondrial disease

Answer 3

vastus lateralis

Question 4

The number of mtDNA molecules within developing oocytes is reduced before being subsequently amplified to the huge total seen in mature oocytes.

This restriction and subsequent amplification of mtDNA during oogenesis is termed the

Answer 4

Mitochondrial bottle neck

the variability in the proportion of mutant mtDNA molecules seen in the offspring of a mother with heteroplasmy for a mtDNA mutation arises, at least in part, from the sampling of a reduced subset of the mtDNAs after the mitochondrial bottleneck that occurs in oogenesis

Question 5

commonly caused by A3243G

point mutation in the tRNA-Leu^UUR

MTTL1

Answer 5

MELAS

mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke like episodes

Question 6

Mix and Match: CDG

1. Bone Skin and Growth problems
2. Brain, eye, muscle involvement
3. Seizures and intellectual disability
4. Protien losing enteropathy
5. Second most common CDG

A. MPI-CDG (CDGIb)

B. O-linked disorders

C. Glucosyltransferase 1 def (ALG6-CDG)

D. GPI-anchor disorders

E. Dolichol defects

Answer 6

1. E
2. B
3. D
4. A
5. C

Question 7

Mix and Match CDG

1. CDGIa
2. First flippase disorder
3. Activated sugars used include fructose, xylose and mannose
4. Treated with mannose
5. COG2 and COG3

A. Phosphomannose Isomerase def (MPI-CDG) CDGIb

B. O-linked disorder

C. Phosphomanomutase def (PMM2)

D. No human disease to date

E. RFT1

Answer 7

1. C
2. E (also associated with deafness)
3. B
4. A
5. D

Question 8

CDG associated with sever cardiomyopathy requiring transplant

Answer 8

DOLK1-CDG

Question 9

Physical exam findings of patients with PMM2-CDG (CDG1a)

Answer 9

Cherubic facies

orage peel skin

inverted nipples

abnormal fat pads

prognathia

peripheral neuropathy

Question 10

N-linked gycosylation functions

Answer 10

• protien folding and stability
• protien-protien complex formation
• protease resistance
• signaling
• cell-cell interations

Question 11

O-linked gylcosylation functions

Answer 11

• Antibacterial function in saliva
• Defines ABO blood groups
• Sperm motility, sperm-egg binding, prevent polyspermia
• Cell adhesion/migration
• lymphocyte targeting and inflammatory response