A recently published study reports the range of phenotypes of a large number (187) of French patients with fatty acid beta-oxidation defects (FAODs). The study highlights that the liver is the main organ involved at diagnosis regardless of age at diagnosis, classical phenotype (i.e. cardiac, hepatic, or muscular), or enzyme deficiency. Hepatic symptoms were present in 89% of patients and the most frequent symptoms were: hepatomegaly (92%), increased blood alanine aminotransferase (ALT) level (82%), and steatosis (88%). Other frequent features included Reye syndrome (49%), increased gamma-glutamyltranspeptidase (GGT) (37%), and liver failure (27%). Although steatosis may be observed in various inherited metabolic defects, it is a reliable indicator of FAOD and should prompt systematic screening when the diagnosis is suspected.
Extrahepatic features included hypoglycemia (75%), neurological (64%), muscle (61%), or cardiac features (55%) [as either cardiomyopathy (47%) or arrhythmias (31%)]. Hemodynamic events (41%) were represented by shock (31%) or sudden death (35%). Hyperammonemia (73%) and hyperlactacidemia (57%) were the two main biochemical features.
Posted by Nicola Brunetti-Pierri, MD