The majority of proteins that constitute mitochondria are encoded by over 1,300 nuclear genes, inherited from both mother and father.

“But the majority of proteins that make up mitochondria, over, I think, 1,300 genes that make up mitochondria are actually encoded in the nuclear DNA. And so you inherit a copy from both your mother and your father. So the majority of people who have mitochondrial defects or rare mitochondrial diseases actually could inherit them from either mom or dad because it can be a defect in the nuclear genes”