Table 1.

Results obtained by analyzing DBS samples from confirmed cases of methylmalonic acidemia from our laboratory archives.

Sample typeMMA concentration, μmol/LDate of specimen,1 dayDate of assay,2 month
MedianRange
Newborn screening (n = 5)3232.0200.5–343.61–53–104
Symptomatic neonates (n = 17)133.417.4–1451.12–83–106
Known case (n = 11)268.7128.6–981.15–29200–107
  • 1 Date of collection of specimen from neonate or patient.

  • 2 Age of sample when assayed by current method.

  • 3 All newborn screening specimens were from asymptomatic infants; one specimen was from a high-risk family.