I understand that it causes low blood sugar due to ATP depletion in hepatic cells and thus less ATP for gluconeogenesis, since there is less DHAP available for glycolysis, and glyceraldehyde can only contribute to glycolysis if phosphorylated with triose kinase, which is not highly expressed in the liver (anything else I'm missing here?)

But as for lactic acidosis, I am quite confused. I don't see how a build up of Fructose-1-Phosphate can result in excess lactic acid being formed. So there is a deficiency in Aldolase B, meaning you can't cleave the F-1-P into DHAP and glyceraldehyde. You're stuck with F-1-P, which I would assume just gets transported into urine but F-1-P can't leave cells unless dephosphorylated, and I am not sure if there is a phosphatase available for that reaction.

Anyway the only means by which lactic acid is formed that I am familiar with is anaerobic respiration (pyruvate -> lactic acid) but seriously I can't think of how a buildup of F-1-P results in lactic acidosis.

Go here to read the rest:
Biochemistry r/Biochemistry - reddit