The A2 approach performed for the SPAST-related case suggested that a homozygous deletion in LDHA, causing Glycogen storage disease due to lactate dehydrogenase M-subunit deficiency (ORPHA:284426) [38] deserved further investigation and could contribute to the phenotype of this case, one that could not be diagnosed as a Pure spastic paraplegia type 4 (ORPHA:100985). The gene discussed is LDHA; the disease is disorder of glycogen metabolism.