Answer:
mitochondria
Step-by-step explanation:
Ideally, living cells including that of humans, breakdown the food they ingest in order to assess the stored energy in them and convert it to a usable form by their cell (ATP). This process is called Cellular Respiration and it is carried out by the MITOCHONDRION organnelle, which is due to this reason regarded as the power house of the cell.
In a case where an inherited syndrome affects the cell's ability to convert food to energy, the malfunctioning organnelle would be the Mitochondrion because that's the function of the organnelle.