ADA and hepatitis A virus infection: In comparison, a severe degree of hepatic impairment is not normally seen in ADA-deficient patients, although there is a case report of a patient with ADA-deficient SCID who developed rapid fatal hepatic failure which could not be attributed to infection [26], and a neonate with ADA-deficient SCID with hepatitis and hyperbilirubinaemia which resolved with ERT [27].