mass screening using tandem mass spectrometry: friend or foe? dawn c. allain, ms, cgc childrens...

Mass Screening Using Tandem Mass Spectrometry:

Friend or Foe?

Dawn C. Allain, MS, CGCChildren’s Hospital of Wisconsin

History of NBS

1957 - Dr. Centerwall

1961 - Dr. Guthrie

1963 - MA and OR implement legislation

History of NBS

1997 - NC begins piloting MS/MS

1999 - NC and MA begin newborn screening with MS/MS

2000 - WI begins MS/MS NBS

States Screening by MS/MS

Maine Massachusetts Minnesota North Carolina Ohio Wisconsin

** as of September 2001 – www.tylerforlife.com

Why Use MS/MS?

Small sample size requirement Fast Screens for many diseases Cost Public awareness and advocacy

Mass Spectrometry

Ion separation and quantification

Produces charged particles

Uses electrical and magnetic fields

Detection system

Sansom, Molecular Medicine Today, March 1999

MS/MS Analysis

Aminoacidopathies

Organic acidurias

Fatty acid oxidation disorders

Aminoacidopathies

Arginosuccinic Aciduria

Citrullinemia

Homocystinuria

Maple Syrup Urine Disease

Phenylketonuria

Tyrosinemia

Organic Acid Disorders

2,4-Dienoyl-CoA Reductase Deficiency

3-Hydroxy-3-Methylglutaryl-CoA Lyase Deficiency

3-Ketothiolase Deficiency

Organic Acid Disorders

3-Methylcrotonyl-CoA Carboxylase Deficiency

3-Methylglutaconyl-CoA Hydratase Deficiency

Glutaric Acidemia Type I

Organic Acid Disorders

Isovaleric Acidemia

Methylmalonic Acidemia

Mulitple CoA Carboxylase Deficiency

Propionic Acidemia

Fatty Acid Oxidation Disorders

3-Hydroxy Long Chain Acyl-CoA Dehydrogenase Deficiency (LCHAD)

Carnitine Palmitoyl Transferase Deficiency Type II (CPT II)

Long Chain Acyl-CoA Dehydrogenase Deficiency (LCAD)

Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCAD)

Fatty Acid Oxidation Disorders

Multiple Acyl-CoA Dehydrogenase Deficiency (Glutaric Aciduria type II)

Short Chain Acyl-CoA Dehydrogenase Deficiency (SCAD)

Very Long Chain Acyl-CoA Dehydrogenase Deficiency (VLCAD)

Newborn Screening Criteria

Criteria Incidence >1/100,000 Significant

morbidity/mortality Successful treatment Reasonable cost Technology

OA/FAOD/AA 1/5,000 to 1/10,000 Severe medical

complications/death Diet & avoid fasting < $10.00 MS/MS

False Positives

Cut-off levels of acylcarnitines may be too low

TPN feedings Prematurity Sampling Error

False Negatives

Cut-off levels of acylcarnitines may be too high

Mild clinical course

Sampling Error

Follow-up

Positive MS/MS NBS Result

PMD called and faxed resultsConsultant names providedMedical management recommendedF-up by PMD or Genetic Center

Organic Acidemia Follow-Up

Initial Follow-Up

Urine organic acidsAcylcarnitine profilePlasma carnitinePlasma amino acids

Additional OA Follow-Up

Enzyme analysis in lymphocytes

Enzyme analysis in fibroblasts

Molecular testing

Fatty Acid Oxidation Follow-Up

Initial work-up

Urine organic acidsUrine acylglycinesAcylcarnitine ProfilePlasma carnitineDNA mutations (MCAD and LCHAD)

Other FAOD Work-Up

Fibroblast studies Fatty acid oxidation studies Direct enzyme analysis Western blot

Test siblings

Aminoacidopathy Follow-Up

Initial work-upPlasma amino acids

Other Laboratory AnalysisOrotic acid AmmoniaUrine organic acidsDNA analysis

Wisconsin Experience

Pilot testing began May 1999 Analyzed all specimens received Established instrument reliability Developed reporting policies Developed follow-up protocols

Routine testing began April 2000 OA and FAO disorders only

Wisconsin ExperienceOrganic Acidemia

1 - PA

2 - 3-MBCDD

2 - C3/C212 - C3 2 - C5,C5/C3 1 - C5/C2,C5/C3 5 - C5 1 - C3, C5

23Possible

5 – 3-MCC2 - MMA

1 - MA

8 - C5OH 5 - C3,C3/C218 - C5,C5/C3,C5/C2 1 - C3DC 1 - C5DC

33Definite

3-MCC Case Study

Initial NBS result (6/7/01) C5OH = 6.45 (>0.6)

Referred to state consultant (6/9/01) Patient seen on 6/12/01 F-up laboratory analysis Results obtained (6/15/01) Sibling tested (6/22/01)

3-MCC NBS Issues

Prevalence

Diagnosis

Severity

Wisconsin ExperienceFAOD

1 - SCAD10 - C47 - C101 - C6,C8,C101 - C14,C14:1, C14:22 - C14,C14:11 - C10,C161 - C16,C18,C16:1,C18:1

24Possible

4 - SCAD2 - MCAD1 - GAII

5 - C4,C4/C2,C4/C32 - C6,C8,C10:1,C8/C101 - C4,C5,C14,C161 - C14,C14:1,C14:2,C16:1

9Definite

SCAD - NBS Issues

Prevalence Mild presentation 2 homozygous for G625A

polymorphism*

*Corydon et al, Ped Res 49 (1):28-23, 2001

Wisconsin ExperienceAminoacidopathies

3 Tyrosinemia – none confirmed

1 Citrullinemia - confirmed

Tyrosinemia Issues

Transient tyrosinemia

Prematurity

False negatives

Impact of NBS by MS/MS on Families

Anxiety

Unknown

Limited Resources

Impact of NBS by MS/MS on State Laboratories

Start-up cost/New technology

Programming

False negatives and false positives

Detection of undefined disorders

Impact of NBS by MS/MS on Genetic Clinics

Increased clinic load Long-term treatment Improved quality of life Natural history

Summary

Collaboration

Close Follow-up

Supportive Counseling

Acknowledgements

WI Newborn Screening Laboratory Gary Hoffman, PhD

Children’s Hospital of Wisconsin William J. Rhead, MD, PhD

Waisman Center, UW Jon Wolff, MD, PhD Kristine Hanson, MS, CGC