Amino acid disorders

@ganesh-kumar

 

Hi!! It's always exciting to answer your questions 😀To save your precious minutes first read the edge then glimpse through this🙃

Let's not learn all aminoacid disorder together..let us divide into parts 

Our target 

1.phenyl ketonuria

Phenylalanine (essential aa) cannot be synthesized in body.taken through diet

Tyrosine is twin of Phenylalanine with additional hydroxy group .non essential(so our body synthesis Tyrosine from Phenylalanine by hydroxylase) defect classical PKU (Phenylalanine Inc;Tyrosine reduced)non essential aa

^Phenylalanine------>tyrosine(dec) clinical manifestation d/t this

So it's irreversible reaction 🤔( if it was reversible then we can syn Phenylalanine in our body and it will become an non essential aa this doesn't happen)

All the below hydroxylase/enzyme req bh4 as cofactor 

1.Phenylalanine hydroxylase 

2.tyrosine hydroxylase 

3.tryptophan hydroxylase 

4.NO synthase

Cofactor def(bh4) either production or recycling defect cause non classical pku aka malignant pku🤔along with PAH all other enzymes affected .synthetic tetrahydrobiopterin  form SAPROPTERIN for treatment. 

So keep it simple; pah classic pku

Bh4 non classic pku 

Manifestation d/t Inc Phenylalanine and Dec Tyrosine tryptophan

Phenylalanine. brain damage,Guthrie test

Phenylalanine pyruvate- fecl3 test in urine(pee)

Phenylacetate- mousy odour (dka acetone gives fruity odour)

Hope this helps 

Do share your honest feedback 🙂helps me improve my content!!

 

@aps Thanks a lot ka !! Highly conceptual !! A sooperb edge !! 

Hi!! Let's move to Tyrosine

sorry for the delay 🙃 see the edge first to save time .. 

The difficult part for me is to remember which enzyme is for which Tyrosinemia..let's have some mnemonic for this

Tyrosinemia type 1 (First)- Fumaryl Acetoacetate hydrolase (FAH)

 type 2  (Two) - TyrosineTransaminase

Type 3 - ParahydroxyPhenylPyruvate (3 P) hydroxylase

Now let's  look at flowchart in image ..

Hepatorenal tyrosinemia (type 1)

When FAH is defective FAA accumulates which is coverted into succinyl acetone (manifestation d/t this)

boiled cabbage odour (Dka fruity odour - acetone)

Accumulates in liver - cirrhosis (increase risk HCC)

Accumulates in Kidney - rickets (fanconi syndrome)

Rx: get rid of succinyl acetone (nitisinone-NTBC) blocks PPP hydroxylase .. inturn decrease FAA and decrease Succinyl acetone 

diet  with low Phenylalanine and Tyrosine inturn decrease succinyl acetone 

Richner Hanhart /occulocutaneous tyrosinemia

Type 2 - Tyrosine Transaminase

Here Tyrosine ----->phpp is blocked 

Tyrosine crystals accumulates in eye and skin .B/L corneal ulcer and Palmoplantar keratoderma. 

Type 3 - PPP hydroxylase 

Complete - neonatal tyrosinemia transient condition seen in premature infants  because liver is immature 

Partial - hawkinsinuria (swimming pool odour)

 

 

 

 

 

@aps Sooper ka