Prevalence of Metabolic Liver Disorders in Children Attending Gastroenterology and Hepatology Unit at Assuit University Children Hospital.

Metabolic Liver Disease is a group of metabolic disorders that stops the liver to function or fail. These metabolic conditions affect the pathways in the liver cells - the pathways that help the body break down, absorb, process, transport, and store nutrients like amino acids, carbohydrates and fats.

Metabolic liver diseases (MLD), an inborn error of metabolism, is caused by defect of single enzyme or transport protein resulting into abnormality in synthesis or catabolism of carbohydrate, protein and fat.

The pathogenesis of MLD can be divided into three groups:

1. Defect in the intermediary metabolic pathway leading to accumulation of toxic metabolite (ex : Galactosemia, Tyrosinemia type 1)
2. Involvement of cellular organelles : (Wolman's disease and Zellweger's syndrome)
3. Energy deficiency states (Mitochondrial or Cytoplasmic):(ex : fatty acid oxidation defects (FAOD) and the congenital lactic acidemias) The MLDs can present at any age, from prenatal, neonatal, infancy to adolescence and even adulthood, coinciding with the time of maximum catabolism. From the therapeutic point of view, the MLDs can be divided into four time periods e.g., neonatal age, at the time of infections, puberty and pregnancy. The diagnosis is often delayed as the symptoms may be intermittent, and in the period between episodes of decompensation, the patient may be free of clinical or biochemical abnormalities.

MLD can have varied presentations in infants and children, most common of them being: (i) organomegaly, (ii) encephalopathy due to hyperammonemia and/or primary lactic acidemia, (iii) pediatric acute liver failure (ALF), (iv) cirrhosis with or without portal hypertension, and (v) cholestatic liver disease.A high index of suspicion for MLD is important as urgent intervention such as dietary manipulation or disease-specific treatment may be life- saving.The outcome of patients undergoing liver transplantation for MLD has improved considerably over the last decade.Moreover, it is important to establish the correct diagnosis, so that appropriate genetic counselling can be offered to the family.MLD merit special attention in differential diagnosis of pediatric ALF, especially in infants and young children in whom they constitute 13- 43% of all cases .