UREA CYCLE DISORDERS

Course overview

UREA CYCLE DISORDERS ARE INBORN ERRORS OF METABOLISM RESULTING FROM DEFECTS IN ONE OF THE ENZYMES OR TRANSPORTER MOLECULES INVOLVED IN THE HEPATIC REMOVAL OF AMMONIA FROM THE BLOODSTREAM. REMOVAL OF AMMONIA FROM THE BLOODSTREAM NORMALLY OCCURS VIA ITS CONVERSION TO UREA, WHICH IS THEN EXCRETED BY THE KIDNEYS. CONSEQUENTLY, UREA CYCLE DISORDERS LEAD TO AN ACCUMULATION OF AMMONIA. AMMONIA IS EXTREMELY TOXIC, PARTICULARLY TO THE CENTRAL NERVOUS SYSTEM. NEWBORNS WITH SEVERE MUTATIONS IN ANY ONE OF THE FIRST FOUR ENZYMES OF THE UREA CYCLE CAN BECOME CATASTROPHICALLY ILL WITHIN 36 TO 48 HOURS OF BIRTH DESPITE APPEARING NORMAL AT BIRTH. IT IS THEREFORE POSSIBLE FOR A NEWBORN TO BE DISCHARGED FROM THE HOSPITAL BEFORE SIGNS OF UREA CYCLE DISORDERS DEVELOP. THE NEWBORN MAY SUBSEQUENTLY DEVELOP SIGNS THAT GO UNRECOGNIZED AT HOME. HYPERAMMONEMIA IS KEY TO THE DIAGNOSIS OF UREA CYCLE DISORDERS AND TREATMENT SHOULD NOT BE DELAYED WHILE A DEFINITIVE DIAGNOSIS IS SOUGHT. THIS ACTIVITY REVIEWS THE EVALUATION AND MANAGEMENT OF UREA CYCLE DISORDERS AND HIGHLIGHTS THE ROLE OF INTERPROFESSIONAL TEAM MEMBERS IN COLLABORATING TO PROVIDE WELL-COORDINATED CARE AND ENHANCE OUTCOMES FOR AFFECTED PATIENTS AND FAMILIES.