In summary, we reported the first glycogen storage disease type‐III (GSD‐III) patient with a reported homozygous mutation in AGL caused by whole UPiD 1 and the first Leigh syndrome patient with a novel homozygous mutation in SURF1 caused by whole UPiD 9 through the non‐Mendelian inheritance of two mutant copies of a gene from the father. Here, AGL is linked to disorder of glycogen metabolism.