Tyrosinemia Type 1: An Overview of Nursing Care
Tyrosinemia type 1 (TT1) is an inherited metabolic disease that can be fatal when not detected early by newborn screening. In the past, children with TT1 had a poor prognosis due to organ failure and neurologic crisis during infancy. Recent improvements in newborn screening have changed the prognosis of affected children. Measurement of succinylacetone by tandem mass spectrometry provides early identification and the opportunity to manage TT1 as a chronic disease. Treatment includes genetic counseling, dietary management, pharmacotherapy, metabolic crisis prevention, and whole organ transplant. Nursing care is critical to successful management when it is based on a clear understanding of the pathophysiology. This overview of nursing care will provide specific recommendations to reduce complications and enhance the quality of life for children with TT1.
Fumarylacetoacetate hydrolase (FAH) deficiency or tyrosinemia type 1 (TT1) is an inherited metabolic disease that can cause neurologic crisis and respiratory distress. An inborn error of metabolism, TT1 is a rare disease with a worldwide incidence of approximately one to two cases per 100,000 births, although in some populations, the incidence is much higher (Scott, 2006). It is a life-threatening disorder that is usually fatal before two years of age if not treated effectively. Larochelle et al. (1967) described TT1 in infants presenting with a painful neurologic disorder that was associated with ascites, liver failure, failure to thrive, coagulopathy, rickets, renal disease, and a cabbage-like odor. Since first described in the Canadian population, much has been learned about the disease. In the Saguenay Lac-St. Jean region of Quebec, Canada, the incidence is approximately one case per 1846 births (De Braekeleer & Larochelle, 1990; Paradis, 1996). There is reliable evidence that inborn errors of metabolism contribute to incidence of sudden infant death syndrome (SIDS), although actual numbers are difficult to quantify (Bennett & Rinaldo, 2001; Centers for Disease Control and Prevention [CDC], 2003; Hunt & Hauck, 2006).
Mandatory newborn screening saves lives, and diagnostic accuracy improves outcomes for children with TT1 (McHugh et al., 2011; Schunemann et al., 2008). When TT1 is identified by enhanced newborn screening methods, the disease is treatable (Turgeon et al., 2008). If not identified on newborn screening, children with the disease can present critically ill in metabolic acidosis. Children with inborn errors of metabolism are identified post-mortem when newborn screening fails to identify the disease in the neonate (Bennett & Rinaldo, 2001; CDC, 2003; Chace et al., 2001). Early identification and diagnosis are life-saving for these metabolically unstable patients. The pediatric nurse needs to understand the pathophysiology of the disease and nursing interventions that will improve patient outcomes to successfully intervene. An overview of the pathophysiology and nursing care will enhance outcomes when applied at the bedside.
Abstract and Introduction
Abstract
Tyrosinemia type 1 (TT1) is an inherited metabolic disease that can be fatal when not detected early by newborn screening. In the past, children with TT1 had a poor prognosis due to organ failure and neurologic crisis during infancy. Recent improvements in newborn screening have changed the prognosis of affected children. Measurement of succinylacetone by tandem mass spectrometry provides early identification and the opportunity to manage TT1 as a chronic disease. Treatment includes genetic counseling, dietary management, pharmacotherapy, metabolic crisis prevention, and whole organ transplant. Nursing care is critical to successful management when it is based on a clear understanding of the pathophysiology. This overview of nursing care will provide specific recommendations to reduce complications and enhance the quality of life for children with TT1.
Introduction
Fumarylacetoacetate hydrolase (FAH) deficiency or tyrosinemia type 1 (TT1) is an inherited metabolic disease that can cause neurologic crisis and respiratory distress. An inborn error of metabolism, TT1 is a rare disease with a worldwide incidence of approximately one to two cases per 100,000 births, although in some populations, the incidence is much higher (Scott, 2006). It is a life-threatening disorder that is usually fatal before two years of age if not treated effectively. Larochelle et al. (1967) described TT1 in infants presenting with a painful neurologic disorder that was associated with ascites, liver failure, failure to thrive, coagulopathy, rickets, renal disease, and a cabbage-like odor. Since first described in the Canadian population, much has been learned about the disease. In the Saguenay Lac-St. Jean region of Quebec, Canada, the incidence is approximately one case per 1846 births (De Braekeleer & Larochelle, 1990; Paradis, 1996). There is reliable evidence that inborn errors of metabolism contribute to incidence of sudden infant death syndrome (SIDS), although actual numbers are difficult to quantify (Bennett & Rinaldo, 2001; Centers for Disease Control and Prevention [CDC], 2003; Hunt & Hauck, 2006).
Mandatory newborn screening saves lives, and diagnostic accuracy improves outcomes for children with TT1 (McHugh et al., 2011; Schunemann et al., 2008). When TT1 is identified by enhanced newborn screening methods, the disease is treatable (Turgeon et al., 2008). If not identified on newborn screening, children with the disease can present critically ill in metabolic acidosis. Children with inborn errors of metabolism are identified post-mortem when newborn screening fails to identify the disease in the neonate (Bennett & Rinaldo, 2001; CDC, 2003; Chace et al., 2001). Early identification and diagnosis are life-saving for these metabolically unstable patients. The pediatric nurse needs to understand the pathophysiology of the disease and nursing interventions that will improve patient outcomes to successfully intervene. An overview of the pathophysiology and nursing care will enhance outcomes when applied at the bedside.