Alkaptonuria and Gilbert's syndrome: Report of two affected siblings and hepatic ultrastructure in one sibling

Abstract

Siblings affected with two hereditable liver enzyme deficiency disorders, alkaptonuria and idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome), are described. A biopsy specimen of liver from one sibling showed no enzyme activity of homogentisic acid oxidase or bilirubin glucuronyl transferase. Electron micrographs of the liver demonstrated a marked increase in the profiles of the smooth endoplasmic reticulum, frequent dilation of the Golgi apparatus and a peculiar formation of collagen bundles within the space of Disse. The previously reported disruption of the hepatocytic microvilli in Gilbert's syndrome was not found in this patient. Study of the pedigree suggested autosomal dominant inheritance of the Gilbert's syndrome in these siblings. Siblings affected with two hereditable liver enzyme deficiency disorders, alkaptonuria and idiopathic unconjugated hyperbilirubinemia (Gilbert's syndrome), are described. A biopsy specimen of liver from one sibling showed no enzyme activity of homogentisic acid oxidase or bilirubin glucuronyl transferase. Electron micrographs of the liver demonstrated a marked increase in the profiles of the smooth endoplasmic reticulum, frequent dilation of the Golgi apparatus and a peculiar formation of collagen bundles within the space of Disse. The previously reported disruption of the hepatocytic microvilli in Gilbert's syndrome was not found in this patient. Study of the pedigree suggested autosomal dominant inheritance of the Gilbert's syndrome in these siblings.