Zellweger syndrome - autosomal recessive disorder of peroxisome biogenesis due to mutated PEX genes. Hypotonia, seizures, hepatomegaly, early death (within 1 year). β-oxidation of VLCFA happens in peroxisomes so the child seemingly having some sort of congenital metabolic disorder with elevated VLCFAs should have been enough to get the answer without knowing about Zellweger.

Peroxisome = Membrane-enclosed organelle involved in β-oxidation of very-long-chain fatty acids (VLCFA) (strictly peroxisomal process).

Zellweger syndrome

Autosomal recessive disorder of peroxisome biogenesis due to mutated PEX genes.

Hypotonia, seizures, hepatomegaly, early death.

The biggest clue- VLCFA INCREASED : think peroxisome then match the feat you know, eg heatom eagle, jaundice, hypotonia etc.

So I guess now I know that this is Zellweger syndrome which is a disorder of biogenesis of peroxisomes. But would there have been a way to know this without knowing about this syndrome?

I guess if you knew that peroxisomes are involved in beta-oxidation of VLCFAs then you would've known why they are building up in the liver.

Can anyone explain why the hypotonia, jaundice, and facial problems occur?