Expanded Newborn Screening: The Nutrition Perspective

1. Expanded Newborn Screening: The Nutrition Perspective Nutrition 526 November 5, 2008 Beth Ogata, MS, RD bogata@u.washington.edu

2. Nutrition Involvement in NBS • Policy • Diagnostic/coordination • Clinical • Community

3. Example: infant with galactosemia • Symptoms in newborn, if untreated • Vomiting, diarrhea • Hyperbilirubinemia, hepatic dysfunction, hepatomegaly • Renal tubular dysfunction • Cataracts • Encephalopathy • E. coli septicemia result • Death within 6 weeks, if untreated • Also • Duarte variant • galactokinase deficiency • uridine diphosphate-galactose-4-epimerase deficiency Galactose-1-phosphate uridyl transferase (GALT) deficiency

4. Primary source is milk (lactose= galactose + glucose) Secondary sources are legumes Minor? sources are fruits and vegetables Food labels milk, casein, milk solids, lactose, whey, hydrolyzed protein, lactalbumin, lactostearin, caseinate Medications (lactose is often an inactive ingredient) Dietary supplements Artificial sweeteners Example: infant with galactosemia Treatment: eliminate all galactose from diet Monitoring: galactose-1-phosphate levels <3-4 mg/dl

5. Example: Infant with galactosemia POLICY RD participated on State Advisory Board to select disorders, including galactosemia • CLINICAL MANAGEMENT • RD provides nutrition care as member of the Biochemical Genetics Team: • Initiation of formula • Guidelines for monitoring intake • Plans for follow-up • RD as case manager DIAGNOSIS & COOORDINATION “Presumptive positive”  RD in contact with family and local providers to discuss appropriate feeding practices and arrange clinic appointment COMMUNITY RD at local health department provides ongoing education to family, local care providers

6. Nutrition and NBS: Policy • Screening process (disorders, procedures) RD participated in Advisory Board meetings, providing input about nutrition-related treatment • Services and reimbursement Nutrition consultant to state CSHCN Program RD provides input about relevant state Medicaid policies • Training and education RD provides information about management of metabolic disorders to local WIC agencies

7. Nutrition and NBS: Clinical Management – PKU • Phenylketonuria • Phenylalanine hydroxylase • Dihydropteridine reductase • Biopterin synthetase • Establish diagnosis • Presumptive positive NBS results • > 3 mg/dL, >24 hrs of age • Differential diagnosis •  serum phe, nl tyr • r/o DHPR, biopterin defects

8. Current Treatment Guidelines • With effective NBS, children are identified by 7 days of age • Initiate treatment immediately • Maintain phe levels 1-6 mg/dl (60-360 umol/L) • Lifelong treatment

9. Outcome Expectations • With NBS and blood phenylalanine levels consistently in the treatment range • Normal IQ and physical growth are expected • With delayed diagnosis or consistently elevated blood levels • IQ is diminished and physical growth is compromised

10. Clinical Management: PKU Goals of Nutrition Therapy • Normal growth rate • Normal physical development • Normal cognitive development • Normal nutritional status

11. Correct substrate imbalance Restrict phenylalanine intake to normalize plasma concentration Supply product of reaction Supplement tyrosine to maintain normal plasma tyrosine levels Clinical Management: PKU Phenylalanine -------------------//----------------------- Tyrosine (substrate) phenylalanine hydroxylase (product)

12. Goals of Nutrition Support for Phenylketonuria (PKU) • Maintain plasma phenylalanine (phe) between 1-6 mg/dl • Without PKU, phe ~ 1.0 mg/dl • Maintain plasma tyrosine (tyr) between 0.9–1.8 mg/dl • Normal = 0.9-1.8 mg/dl

13. Goals of Nutrition Support for Phenylketonuria (PKU)

14. Phe Levels from NBS to Tx Equilibrium achieved by 14 days of age Diagnostic levels Blood levels every 2 days because of rapid growth

15. Adjustments necessary to maintain “safe” blood phe levels • Usual intake of phe • Newborn on formula • 20 oz x 22 mg phe/oz = 440 mg phe • 1 yo child on “regular” diet • 30 g protein = 1500 mg phe (DRI = 13.5 g) • 7 yo child on “regular” diet • 50 g protein = 2500 mg phe (DRI = 19 g) • Phenylalanine requirement • 250 mg/d

16. Management Tools • Specialized formula provides • 80-90% energy intake • 89-90 % protein intake • tyrosine supplements • no phenylalanine • Phenylalanine to meet requirement from infant formula or foods

17. Regulated by FDA Renal solute load Carbohydrate source Fat source Amino acid source Vitamin and mineral content Designated by clinician Protein/energy ratio Specific amino acid Fluid balance Total protein Total energy Formula Composition

18. Effect of a single amino acid deficiency on growth

19. Food Choices for PKU

20. Sample Menu: ~1 year old • Total Protein: • 32.5 grams • (1625 mg phe) • DRI (protein): • 13.5 grams (~675 mg phe) • Phe requirement: • 250 mg

21. Sample Menu: ~1 year old • To meet 250 mg phe  minus milk, tuna, cottage cheese: • Total Protein:5.5 g • Is this adequate protein to support growth? • Is this adequate energy to support growth? • What about adequacy of other nutrients?

22. Tools of Management: Low protein food products

23. Energy needs: 1000-1300 kcal Protein needs: 20 g Phenylalanine needs: 250 mg Formula prescription: Phenyl-Free: 125 g Similac pdr: 50 g Water to 40 oz Food prescription: 25 mg phe, 200 kcal, 0.5 g protein Typical Food Pattern for a Child with PKU 1 year old, weight & length at 50th %ile for age

24. Monitoring Adequacy of Treatment • Measure plasma amino acids • Maintain in treatment range • Monitor nutrient intake • Restrict phenylalanine, supplement tyrosine, adequate protein, energy, other nutrients to support growth and ensure good health • Monitor growth increments • Typical growth expected • Monitor cognitive development • Typical achievement expected

25. Effective Blood Level Management in Childhood Blood levels once per month, or more frequently if needed for good management

26. PKU Management GuidelinesSelf-management Skills

27. Goal of Lifetime Management of PKU To maintain metabolic balance while providing adequate nutrients and energy for normal physical and intellectual growth

28. Maternal PKU Concerns/Outcomes • Women with PKU are at high risk for delivering a damaged infant • Placenta concentrates phe 2-4x • Microcephaly • Cardiac problems • Infant IQ directly related to maternal blood phe level • Outcome improved with maternal blood phe <2 mg/dl prior to conception and during pregnancy

29. Nutrition and NBS: Community – Glutaric Acidemia, type I • Defect in lysine and tryptophan catabolism • Treatment: • LYS- and TRP- restriction (specialized formula, low protein food pattern) • Riboflavin • Frequent monitoring • Aggressively prevent catabolism  metabolic crisis • Symptoms: • Macrocephaly, frontotemporal atrophy and delayed myelination • Myoclonic seizures, ataxia, choreoathetosis • Intermittent metabolic acidosis Glutaryl-CoA dehydrogenase deficiency

30. Example: Infant with GAI • 12 month old • Medical conditions: • Glutaric acidemia, type 1 (identified by NBS) • Cystic fibrosis • Meconium ileus (repaired) • GER • Goals: optimal nutrition status, avoid metabolic decompensation • Simplified nutrition-related history • Breastmilk (or Isomil)+ Glutarex-1 to restrict lysine • MCT oil, concentrated formula for weight gain; pancreatic enzymes • Solid foods introduced when developmentally appropriate • NG tube  g-tube placed by 2 mo

31. Example: Infant with GAI “The Players” • Family: mother, father, infant, extended family • Biochem team: geneticist, nutritionist, genetic counselor • Pulmonary team: pulmonologist, nutritionist, social worker, nurses • Primary care: pediatrician • Community: therapists, WIC nutritionist, public health nurse, home infusion company

32. Example: Infant with GAI MNT and monitoring plan: • Formula – preparation, “recipe,” tolerance • Blood levels – schedule, lag between draw and results • Growth and nutrient needs – balance approaches for CF and GA1 • Food – introduction of solids, oral aversion • Prioritization • Communication

33. Nutrition and NBS: Community PHN and interpreter make monthly visits to family of young child with MSUD. Through pre-arranged phone calls, we can discuss formula composition and preparation, and solid foods. This helps provide information between regular clinic visits.

34. Nutrition and NBS: Community A woman with PKU is enrolled in te First Steps program (WA State MSS) The RD with PKU Clinic provides consultation to the First Steps RD, about management of amino acid levels.

35. Nutrition and NBS: Community The family of a child with propionic acidemia receives formula from home infusion company. The home infusion RD is able to make home visits to evaluate growth and intake, and communicates with clinic RD. This helps to ensure that the family is able to implement recommendations.

36. Nutrition and NBS: CommunityThe baby has a “positive PKU test” • What were the blood phenylalanine (phe) or other critical elevated blood levels? • When was the sample collected? • What is the protocol for confirming the diagnosis? • When was the diagnosis made? • Did this referral come from a screening test? If so, what is the next step toward diagnosis? • Is the family aware of the results?

37. Information Needed by Community and Metabolic Teams Before MNT is Initiated If an infant has been identified by NBS: • Which NBS results are positive • Birth date and age of the infant • Birth weight and gestational age • Current weight • Current form of feeding, and intake • Current health status of the infant

38. Critical Questions about Follow-up and Coordination of Treatment • Who is your contact at the metabolic center? • What is the recommended treatment for the disorder? • What nutrition intervention is required? How is this monitored? • What is the mechanism for follow-up and testing? • Who will prescribe the specialized formulas? • How will the community and metabolic teams communicate about intervention?

39. The Team

40. NBS and the Community: Challenges • Understand the implications of the results of newborn screening tests • Develop a communication system between the community providers and the metabolic team for support of treatment • Interact with PCPs and families as needed, to support appropriate MNT

41. NBS and the Community:What you need to know • Which disorders are identified by NBS in your state? Where do you find this information? • What is the difference between screening and diagnostic results? • What is the system for follow-up of presumptive positive NBS results? • How do you make referrals to regional genetics clinics and specialty care clinics?

42. Caveats to Ponder • Is it really a disorder? • What are we talking about? • Is GA1 really so different than GA2? • If we’re out of MSUD Analog, can we use MSUD Maxamaid? • Screening vs. diagnosis • Is it really PKU?

43. Scenes from the Annals of Reporting and Acting on NBS Results A primary care physician telephones are reports there is a new baby with PKU and asks that you please start the infant on formula ASAP. • What additional information do you need? • What would you do?

44. Scenes from the Annals of Reporting and Acting on NBS Results You are on-call for the weekend for your local hospital and you receive an order from the newborn nursery on an infant with presumptive galactosemia and a request for the initiation of treatment. • What additional information do you need? • What would you do?

45. Additional Information • Washington State Newborn Screening http://www.doh.wa.gov/ehsph/phl/newborn/default.htm • Star G-Screening, Technology, and Research in Genetics http://newbornscreening.info • National Newborn Screening and Genetics Resource Center http://genes-r-us.uthscsa.edu Building Block for Life Volume 27, No 1. Pediatric Nutrition Practice Group (Expanded NBS) Building Block for Life Volume 30, No 3. Pediatric Nutrition Practice Group (Genetics and Expanded NBS)