Table 1.
List of analytes measured in dried blood spot (DBS) specimens for the monitoring of patients with various inherited metabolic disorders (IMDs).
| Analyte | IMD | Laboratory Instrumentation | Diameter of DBS Used for Analysis | Assay Performance Characteristics | References |
|---|---|---|---|---|---|
| Phenylalanine | PKU | HPLC, UPLC, FIA–MS/MS, LC–MS/MS | 2 × 6 mm 3.2 mm |
UPLC (derivatised) 0.5–197 µmol/L, CVs < 10%, DBS ~36% lower vs. plasma Various studies—DBS 15–28% lower vs. plasma |
[4,5] |
| Tyrosine | PKU, Tyro I, II and III, AKU | HPLC, UPLC, FIA–MS/MS, LC–MS/MS | 2 × 6 mm 3.2 mm |
UPLC (derivatised) 0.5–197 µmol/L, CVs < 10% DBS ~38% lower vs. plasma |
[4] |
| Methionine | HCU | HPLC, UPLC, FIA–MS/MS, LC–MS/MS | 3.2 mm | 0.5–197 µmol/L, CVs < 10% DBS 40% lower vs. plasma |
[6] |
| Homocysteine | Homocystinuria | LC–MS/MS, HPLC | 6 mm, 3.2 mm | 1–100 µmol/L, CVs < 10%, DBS 40–50% lower vs. plasma | [6,7,8] |
| Leucine | MSUD | HPLC, UPLC, FIA–MS/MS, LC–MS/MS | 3.2 mm 2 × 6 mm |
UPLC (derivatised) 0.5–197 µmol/L, CVs < 10% DBS ~ 40% lower vs. plasma |
[4] |
| MMA | Methylmalonic aciduria |
LC–MS/MS | 8 mm | 10–10,000 nmol/L, recovery 95%, CVs < 5% DBS 5–6× lower vs. plasma |
[9] |
| NTBC | Tyro1, AKU | HPLC, LC–MS/MS | 3.2 mm 3.2 mm |
0.1–100 µmol/L, recovery 73%, CVs < 10%, DBS 1.56 × lower vs. plasma 0.05–50 µmol/L, recovery 100%, CVs < 10%, plasma 2.4 × higher vs. DBS |
[10,11] |
| SUAC | Tyro1 | LC–MS/MS | 3.2 mm | 0.1–100 µmol/L, recovery > 99%, CVs < 10% 3.0–250 µmol/L, recovery > 99%, CVs < 6% |
[12,13,14] |
| CO | FAOs and OAs | FIA–MS/MS, LC–MS/MS | 3.2 mm | 0–150 µmol/L, CVs < 10% DBS 30–40% lower vs. plasma |
[15,16] |
| Lyso-Gb3 | Fabry | LC–MS/MS | 3.2 mm 3.2 mm |
0.45–197 nmol/L, recovery—NR, CVs < 10%, DBS and plasma results comparable 0.0–120 ng/mL, DBS ~ 50% lower vs. plasma |
[17,18] |
| 17-OHP | CAH | LC–MS/MS | 3.2 mm | 10–200 nmol/L, recovery 90–110%, CVs < 10%, DBS ~ 35–50% lower vs. plasma | [19,20,21] |
PKU, phenylketonuria; Tyro, tyrosinaemia; AKU, alkaptonuria; MSUD, Maple Syrup Urine Disease; MMA, methylmalonic acid; NTBC, nitisinone; SUAC, succinylacetone; CO, free carnitine; FAODs, Fatty Acid Oxidation Disorders; OAs, Organic Acidurias; Lyso-Gb3, globotriaosylsphingosine; 17-OHP, 17-hydroxyprogesterone; CAH, Congenital Adrenal Hyperplasia; NR, not reported.