Diseases

Question 1

Describe the pathogenesis of VLCAD deficiency.

Answer 1

• Normally VLCAD converts acyl-CoA into enoyl-CoA, which leads to the production of ATP.
• Deficient VLCAD cannot produce enoyl-CoA. Acyl-CoA is converted by upstreams enzymes into acylcarnitine, which causes the accumulation of acylcarnitine and energy shortage.

Question 2

Describe the pathogenesis of Cantu syndrome.

Answer 2

• ## Caused by ATPCC9 mutation, which alters the potassium channel subunit and causes the channel to stay open when supposed to be close.

Question 3

Describe the pathogenesis of Gyrate Atrophy.

Answer 3

• Causes by an OAT deficiency. Normally, OAT enzyme converts ornithine into GSA/P5C. Since the enzyme is deficient, ornithine accumulates.

Question 4

Describe the pathogenesis of LARS1 deficiency.

Answer 4

• Normally, LARS1 loads amino-acids onto tRNAs.
• When LARS1 is deficient, it cannot load amino-acids onto tRNAs. This causes a high translational demand with low amino acid supply.

Question 5

Describe the pathogenesis of pyridoxine-dependent epilepsy.

Answer 5

The enzyme antiquitin is deficient here. Because of this deficiency, it results in the build up of a molecule that interferes with vitamin B6 (i.e. pyridoxine).

Question 6

Describe the pathogenesis of tuberous sclerosis.

Answer 6

Caused by a mutation in TSC1 and/or TSC2. Normally these two proteins go into complex and react to stress and growth factors. When stressed, the complex is activated and protein synthesis is downregulated. When growth factors are present, the complex is inhibited and protein synthesis is enhanced. Defects TSC1 or 2 result in less control of cell growth