Table 1. Identified candidate Down Syndrome (DS) biomarkers.
| Symbol | Chrom | Description (synonym) | Potential |
| Fetal liver-derived markers | |||
| AFP | 4 | alpha-fetoprotein | In use |
| ANGPTL3 | 1 | angiopoietin-like 3 | |
| C5 | 9 | complement component 5 | |
| COL1A1 | 17 | collagen, type I, alpha 1 | Indications |
| COL1A2 | 7 | collagen, type I, alpha 2 | |
| COL2A1 | 12 | collagen, type II, alpha 1 | |
| COL3A1 | 2 | collagen, type III, alpha 1 | Indications |
| COL5A2 | 2 | collagen, type V, alpha 2 | |
| DEFA3 | 8 | defensin, alpha 1 | |
| DLK1 | 14 | delta-like 1 homolog | |
| ELA2 | 19 | elastase 2, neutrophil | |
| GPC3 | X | glypican 3 | |
| IGF2 | 11 | insulin-like growth factor 2 (somatomedin A) | |
| PF4 | 4 | platelet factor 4 (CXCL4) | |
| PPBP | 4 | pro-platelet basic protein (CXCL7) | |
| RRM2 | 2 | ribonucleotide reductase M2 polypeptide | |
| S100A8 | 1 | S100 calcium binding protein A8 (calgranulin A) | |
| S100A9 | 1 | S100 calcium binding protein A9 (calgranulin B) | |
| SPTA1 | 1 | spectrin, alpha, erythrocytic 1 | |
| Placental trophoblast-derived markers | |||
| ADM | 11 | adrenomedullin | |
| ALPP | 2 | alkaline phosphatase, placental | |
| CDH1 | 16 | cadherin 1, type 1, E-cadherin | |
| CDH11 | 16 | cadherin 11, type 2, OB-cadherin | |
| CGA | 6 | glycoprotein hormones, alpha polypeptide | |
| CGB5 | 19 | chorionic gonadotropin, beta polypeptide (βHCG) | In use |
| CRH | 8 | corticotropin releasing hormone | |
| CSH1 | 17 | chorionic somatomammotropin hormone 1 (placental lactogen) | Biomarker |
| CSH2 | 17 | chorionic somatomammotropin hormone 2 | Biomarker |
| EBI3 | 19 | epstein-barr virus induced gene 3 | |
| EGFR | 7 | epidermal growth factor receptor | |
| FN1 | 2 | fibronectin 1 | |
| GH1 | 17 | growth hormone 1 | |
| GH2 | 17 | growth hormone 2, placenta-specific growth hormone | Biomarker |
| IGF2 | 11 | insulin-like growth factor 2 (somatomedin A) | |
| IGFBP1 | 7 | insulin-like growth factor binding protein 1 | Examined |
| INHA | 2 | inhibin, alpha | Biomarker |
| INHBA | 7 | inhibin, beta A (activin A, activin AB alpha polypeptide) | Examined |
| INSL4 | 9 | insulin-like 4 | |
| LGALS13 | 19 | lectin, galactoside-binding, soluble, 13 (PP13) | Examined |
| PAPPA | 9 | pregnancy-associated plasma protein A, pappalysin 1 | In use |
| PGF | 14 | placental growth factor | Biomarker |
| PLAC1 | X | placenta-specific 1 | |
| PLAU | 10 | plasminogen activator, urokinase | |
| PRL | 6 | Prolactin | |
| PSG5 | 19 | pregnancy specific beta-1-glycoprotein 5 | |
| SERPINB2 | 18 | serpin peptidase inhibitor, clade B, member 2 | |
| SERPINE1 | 7 | serpin peptidase inhibitor, clade E, member 1 (PAI1) | |
| SPP1 | 4 | secreted phosphoprotein 1 (osteopontin) | |
| TGFB1 | 19 | transforming growth factor, beta 1 | |
| TIMP3 | 22 | TIMP metallopeptidase inhibitor 3 | |
Potential for DS screening is indicated as follows: In use, currently widely used in 1st or 2nd trimester DS screening (in bold); Biomarker, studies showed overall significant concentrations; Examined, examined as biomarker but not significant or inconclusive overall results; Indications, found in high-throughput study but awaiting further study. References on the corresponding literature are given in the Discussion.