Abstract

The concept of a rare disease refers on its prevalence in general population, which is below the threshold of 1/2000. We will introduce the term of “rare hepatitis in children” for those having the same low prevalence in paediatric population. When the prevalence is under 1/10 000, we speak of an “ultrarare” hepatitis. Our aim is to realise a synthesis of rare hepatitis, with genetic and non-genetic origins, illustrating our clinical experience.

Liver is suffering – primarily – in almost all inborn errors of metabolism: carbohydrates or fatty acid beta-oxidation disorders, hyper/dyslipoproteinemia, urea cycle disorders, hereditaries aminoacidopathies, disorders of biliary tract and bile acid synthesis, hemocromatosis, Wilson disease. Lysosomal strorage diseases is a chapter opening widely, with the progress of diagnosis tools: sphingolipidosis (e.g. Gaucher disease), glycogenosis (e.g. I, II), glycoproteinosis, mucolipidosis. Ultrarare hepatitis like peroxisomal or mitochondrial disorders are mentioned. Secondary liver involvement appears in genetic or non-genetic disorders: cystic fibrosis, alpha-1-antitrypsine deficiency, polycystic kidney disease (AR) and autoimmune diseases, respectively. We present clinical picture highlights for each entity, general or specific laboratory work-up, including the enzymatic assay and molecular diagnosis. Prognosis is mentioned in actual context, when DNA recombinant technology is developing, making possible the enzyme replacement or the biologic therapies. From our cohort of 380 cases, admitted in 9½ years (July 2006–January 2016), we have selected 85 non-infectious hepatitis: 33 were congenital hepatic fibrosis, 5 autoimmune hepatitis, 2 glycogenosis and 3 secondary liver involvement in cystic fibrosis. We present other 43 patients with cirrhosis, 9 secondary to biliary atresia, 7 primary biliary cirrhosis, 2 autoimmune and 2 in cystic fibrosis and 3 gangliosidosis. One child had propionic academia. We will refer especially to the rare causes, detailing 6 patients.