Primary Bile Acid Disorders: A Largely Unknown Group of Rare Genetic Diseases in Newborns

Primary bile acid disorders (BASD) in newborns are rarely found with a prevalence of 1-9/1,000,000 and include 1-2 % of all cases with neonatal cholestasis. Causes are different gene defects, which lead to liver enzyme defects, which play a major role in both cholic acid pathways, the classical with production of cholic acid and the alternative one with chenodeoxycholic acid. They are found in both genders in the same distribution. Early diagnosis is very important to introduce a bile acid replacement therapy as soon as possible as the treatment of choice to date. Diagnosis will be confirmed by molecular trsting, liver biopsy and different forms of mass spectrometry methods. Differential diagnosis includes progressive familial intrahepatic cholestasis, neonatal hepatitis and biliary atresia. Further gene therapy approaches must be developed, like CRISP Cas9 technology, to repair the spontaneous point mutations on DNA of these patients to cure and not to treat them their whole life finally.