The topic for this current issue (24.4) is near and dear to my heart: Genetic Metabolic Dietetics. Not a familiar term at the beginning of my career, it is a specialty with a new image. Genetic metabolic dietetics has evolved rapidly as scientific discoveries and technology have advanced the screening, diagnosis, and treatment of patients with inherited metabolic disorders or, as I knew them, inborn errors of metabolism. My career in a clinical research center began with a very satisfying position, working with patients with homocystinuria and other inborn errors of metabolism. Today I would be thrilled to still be practicing in genetic metabolic dietetics!!
Professor Dianne Frazier provides an overview of tandem mass spectrometry and its substantial influence on diagnosing and treating inborn errors of metabolism. Progress in identifying rare disorders on newborn screening panels will expand the opportunities and challenges for healthcare professionals to diagnose and treat infants and children and to educate themselves and the public.
A popular topic at the 2008 Genetic Metabolic Dietitians International Conference was reimbursement of medical foods and the untangling of state legislative mandates by Huntington and Buist. Insurance reimbursement varies across the states and complicates the equitable delivery of health and nutrition services for individuals identified through newborn screening who need treatment of genetic metabolic conditions. They call for the establishment and implementation of uniform standards of care and reimbursement in the United States.
Carol Williams has compiled a compendium of resources that can be particularly beneficial to dietetic practitioners, their patients, and caregivers. Resource management is important for inherited metabolic diseases because of the need for physical and emotional support. New developments in screening, diagnosis, research, and treatment are featured in the selected references and should be helpful to both consumers and healthcare professionals.
Phenylketonuria (PKU) has been treated by diet therapy since the mid-60s. Thompson and Rohr highlight patient-specific therapies being incorporated into care today to improve health outcomes and quality of life for those living with PKU. LaVoie and her colleagues provide the findings of a small study with PKU patients and controls to compare essential fatty acid concentrations. An area of controversy among researchers, this study found adequate essential fatty acid concentrations in both the controls and those with PKU. Freehauf et al provide details of a PKU conference that assisted patients with managing their condition by increasing their effectiveness in adhering to diet. Focused on adolescents and adults and their families, a culinary academy was created. Various factors produced an exciting and successful conference as measured by participants at the conference and 4 months later.
Two organic acidemias, methylmalonic acidemia and propionic acidemia, are difficult conditions to manage. Reineking et al present 3 case studies of infants with these conditions who have received liver and/or kidney transplants, emphasizing medical nutrition therapy.
Gillingham and her colleagues investigated responses to fasting, feeding, and exercise in individuals with long-chain 3-hydroxyacl CoA dehydrogenase or trifunctional protein deficiencies. They found feeding a mixed-meal suppressed plasma 3-hydroxyacylcarniture levels and exercise increased them. Further research is warranted to corroborate these findings.
A case study by Pendyal and Muenzer was reported, explaining the diagnosis and management of mild citrullinemia for a child from infancy to the age of 2 years. The approaches taken, including a normal protein diet, resulted in normal growth and development.
Emergency management of inherited metabolic disorders is a critical area of patient care and requires immediate intervention for those in crisis. Advances in newborn screening may allow earlier detection of potential problems. Mofidi and Kronn focus on the principles of diet management with an emphasis on total parenteral nutrition and "the steps necessary to minimize the frequency, duration, and severity of catabolic crisis in infants and children."
My deepest appreciation goes to Kathy Camp, MS, RD, CSP, who, as President of the professional organization Genetic Metabolic Dietitians International (GMDI), initiated, inspired, and implemented this important issue. The articles reflect some of the key concepts presented at the biannual conference, "Bridging Science and Clinical Practice" in Atlanta in 2008. I also want to recognize Fran Rohr, MS, RD, the current GMDI president who served as advisor, author, writer, and supplier of the brochure for the 2010 conference information, "Navigating Changes in Nutrition Management of Genetic Disorders" (see below). Thanks to all of the authors, editors, and reviewers for another great year for the journal, Topics in Clinical Nutrition.
-Judith A. Gilbride, PhD, RD, FADA
Editor