Organic Acid Disorders
Brief Description
These metabolic disorders cause a buildup of toxic organic acid intermediates due to the body's inability to breakdown certain amino acids and odd-chain organic acids. Most of these disorders have severe forms that present in the first week of life and constitute a neonatal emergency. Newborns identified to be at risk for an organic acid disorder are referred to a contracted medical center for diagnostic evaluation.
The list of organic acid disorders that we screen for are:
2-Methyl-3-hydroxybutyric aciduria (2M3HBA)
2-Methylbutyryl-CoA dehydrogenase deficiency (2MBG)
3-Hydroxy 3-methylglutaric aciduria (HMG, 3-Hydrox 3-methylglutaryl-CoA lyase)
3-Methylcrotonyl-CoA carboxylase deficiency (3-MCC)
3-Methylglutaconic aciduria (3MGA, Type I hydratase deficiency)
Beta ketothiolase (BKT, mitochondrial acetoacetyl-CoA thiolase, short-chain ketoacylthiolase)
Glutaric acidemia type I (GA-1, glutaryl-CoA dehydrogenase)
Isobutyryl-CoA dehydrogenase deficiency (IBG)
Isovaleric acidemia (IVA, Isovaleryl-CoA dehydrogenase)
Malonic acidemia (MAL, malonyl-CoA decarboxylase)
Methylmalonic acidemia (CBL A,B; vitamin B12 disorders)
Methylmalonic acidemia (CBL C,D)
Methylmalonic acidemia (MUT, methylmalonyl-CoA mutase)
Multiple carboxylase deficiency (MCD, holocarboxylase synthetase)
Propionic acidemia (PROP, propionyl-CoA carboxylase)
Laboratory Unit
Methodology
Tandem Mass Spectrometry (MSMS)
Specimen Collection
Missouri newborn screening samples must only be collected on the Food and Drug Administration (FDA) approved blood collection forms that must be pre-purchased from the MSPHL. The optimum collection time is between 24 and 48 hours-of-age. The instructions for collecting the samples are listed on the back of the collection form. All 5 circles on the filter paper need to be filled with blood from one side and then air dried for at least 3 hours in a horizontal position without allowing the blood to touch any surface during drying, including other parts of the card (see image).
See
"Rules for Collection".
Storage/Transport
Store the dried blood samples at room temperature in the envelopes provided by the MSPHL and transport within 24 hours of collection.
Acceptable Specimen Type(s)
Initial Screen (the red form) or Repeat Screen (the green form)
Test Request Form(s)
Included in kit
Possible Results
Normal - The final newborn screening reports are mailed to the submitter and physician of record.
Low Risk - Repeat the newborn screen. If, however, the infant is sick or displays signs of metabolic distress, the physician may wish to conduct diagnostic testing instead of, or in addition to the repeat screen. The final newborn screening reports are mailed to the submitter and physician of record.
Moderate/High Risk - Diagnostic testing and consultation with a metabolic specialist is needed. Final results are phoned and faxed to physician/health care provider and appropriate follow up center. Follow up centers are contracted by the Department of Health and Senior Services (DHSS) for follow up tracking, testing, diagnosis, and counseling.
Unacceptable Conditions
Interfering Substances
NICU Guidelines and Key for NBS
Specimen collection prior to 24 hours of age, prematurity, and illness can all affect the newborn screening results. “No Result” is reported on those specimens collected before 24 hours of age. Administration of pivalic antibiotics during pregnancy or to the baby may cause false positive results for isovaleric acidemia (IVA).
Result Reported
1 to 3 working days after receipt of specimen.
Fees
$95 charge – for full panel of screening disorders
CPT Codes
83789
LOINC/SNOMED Codes
N/A
Additional Information
Prevalence of Disorder: 1:9,000 in Missouri
For more information on this Disorder, visit the DHSS Newborn Screening website.