PIGA and intervertebral disk degenerative disorder: Unlike patients with severe phenotypes, the less severe form of PIGA germline mutations (patients: IV-2 [7], 3 and 4 [18]) did not involve facial dysmorphism and multiple CNS abnormalities, but did present with early onset of infantile spasms with hypsarrhythmia on EEG (Table 1), and generally longer life span marked by IDD, treatable seizures and PDD (Table 1).