Table 1.
Studies focused on salivary nucleic acids in autism.
| Children No. ASD No. Non-ASD Geographic Region |
ASD Dg. Tool/ Module |
Age (Years) ASD Non-ASD |
Timing | Saliva Collection and Nucleic Acids Extraction | Duration of Sal/Volume | Centrif | Marker | Method | Results ↓↑ in ASD |
Ref |
|---|---|---|---|---|---|---|---|---|---|---|
| ASD: 5 M, 2 F SA: 2 M, 4F Non-ASD (Down syndrome, Opitz GBBB syndrome): 1 M, 1 F NA |
NA | 12 ± 9.07 6.5 ± 3.64 6 ± 1 |
noon | Salivette | 2 min/0.1–2 mL | 1500 g 10 min |
DNA- SNPs CYP1A2*1C CYP1A2*1K CYP1A2*3 CYP1A2*4 CYP1A2*6 CYP1A2*1F |
qPCR | SNP found in eight of fifteen patients, Allele *1C in two patients Allele *1F in six patients |
[58] |
| 457 families with ASD, including 418 simplex and 39 multiplex families NA |
ADOS, ADIR/ 1–4 |
NA | NA | OGD-500 kit (DNA Genotek), DNA extracted in a CLIA-certified laboratory |
NA | NA | DNA-exome | WES | CHD8, SCN2A, ADNP, KDM5B, SYNCAP1, ARID1B, SHANK3, DNMT3A, POGZ, FOXP1, CHD2, GIGYF1, ASXL3, BRSK2, KDM6B, CLCN4, ITSN1, MED13L, IRF2BPL, DMWD, QRICH1, MBD5, CPZ, SLC6A8, FEZF2, PAX5, RERE, RNF25, RALGAPB, NR4A2, EGR3, KDM1B, SH3RF3, DPP6 | [63] |
| ASD (comorbid diagnoses included): 19 M, 5 F Non-ASD: 16 M, 5 F NA |
DSM-5, ADOS, CARS, Krug Asperger Index/ NA |
9.1 ± 2.4 9.2 ± 2.5 |
Non-fasting state, 10 a.m.–3 p.m. |
Rinsing with water, Oragene RNA collection kit (DNA Genotek) Trizol method, purification by RNeasy mini column(Qiagen) |
3 mL | NA | RNA-miRNA | Small RNA sequencing | ↑ miR-628-5p, miR-335-3p ↓ miR-30e-5p, miR-27a-3p, miR-23a-3p |
[66] |
| Training set: ASD 156 M, 32 F Non-ASD (TD or DD): 122 M, 62 F Validation set: ASD: 45 M, 5 F Non-ASD(TD or DD): 26 M, 8 F NA |
DSM-5 criteria/NA | 4.5 ± 1.25 4.08 ± 1.33 4.42 ± 1.25 3.83 ± 1.33 |
NA | Rinsing with water, Oracollect RNA swab (DNA Genotek)/pooled saliva by highly absorbent swab, Trizol method |
NA/5–10 sec | Whole saliva | RNA– human, microbial | Small RNA sequencing |
Diagnostic panel: miR-92a-3p, mir-146b, miR-146b-5p, miR-378a-3p, miR-361-5p, miR-125-5p, miR-106a-5p, miR-3916, mir-146a, mir-10a, mir-410, piR-24684, piR-9491, piR-27400, piR-6463, piR-29114, piR-12423, piR-24085, piR-15023, SNORD118, Leadbetterarella byssophia, Alphaproteobacteria, Fusarium, Staphylococcus, Clostridiales, Pasteurella multocida, Corynebacterium uterequi, Lactobacillus fermentum, Oenococcus oeni, Streptococcus gallotycus, Ottowia, Yarrowia lipolytica |
[71] |
| Training set: ASD: 161 M, 26 F Non-ASD TD: 76 M, 49 F Non-ASD DD: 48 M, 21 FTest set: ASD: 29 M, 8 F Non-ASD TD: 5 M, 3 F Non-ASD DD: 15 M,10 F NA |
DSM-5, ADOS, ADIR, CARS/ NA |
4.5 ± 1.25 3.9 ± 1.5 4.2 ± 1.08 3.9 ± 1.67 4.7 ± 1.67 3.7 ± 1.67 |
Non-fasting state | P-157 Nucleic Acid Stabilizing Swab (DNA Genotek), Trizol method, purification by RNeasy mini column(Qiagen) |
5–10 s | NA | RNA- miRNA | Small RNA sequencing | ↓miR-28–3p, miR-148a-5p, miR-151a-3p, miR-125b-2–3p, miR-7706 ↑miR-665, miR-4705, miR-620, miR-1277–5p |
[73] |
| ASD: 25 M, 14 F Developmental disorder: 14 M, 2 F Non-ASD: 11 M, 14 F Bosnia and Herzegovina |
CARS II/NA | 5.07 ± 1.26 5.03 ± 0.98 5.76 ± 1.67 |
NA | mirVANA isolation kit (Invitrogen™) | NA | NA | RNA- 14 miRNAs |
qPCR | ↑miR-7-5p, miR-2467-5p ↓miR-23a-3p, miR-32-5p, miR-140-3p, miR-628-5p |
[74] |
| Adolescent cohort: ASD: 37 M, 11 F Non-ASD: 26 M, 22 F Younger cohort: ASD: 20 M, 2 F DD: 6 M, 3 F NA |
DSM-5 criteria, ADOS-2/ NA |
11.5 ± 4.45 10.4 ± 3.03 4.36 ± 1.08 3.88 ± 1.05 |
Non-fasting state | Oragene RNA collection kit (DNA Genotek)/Oracollect RNA swab (DNA Genotek), Qiagen miRNeasy MicroKit (Qiagen) |
NA | NA | RNA- miRNA | Small RNA sequencing | Associations between behavior and RNA levels: hsa-miR-146b-5p, hsa-miR-29c-3p, hsa-miR-374a-5p, hsa-miR-182-5p, piR-hsa-24085, piR-has-6463, Staphylococcus Changed over time in younger cohort: hsa-let-7e-5p, hsa-miR-125a-5p, hsa-miR-125b-5p, hsa-miR-146b-5p, hsa-miR-148a-5p, hsa-miR-182-5p, hsa-miR-221-3p, Staphylococcus |
[75] |
| ASD: 60 M, 16 F nonASD: 28 M, 11 F NA |
ADOS, ADIR/ NA |
6.9 ± 1.5 6.9 ± 1.8 |
No eating or drinking for at least 3 h prior to saliva collection between 8:30 and 10:30 a.m. |
Non-stimulated, Qiagen miRNeasy Mini Kit (Qiagen), PureLink Genomic DNA Kit (Thermo Fisher Scientific) |
800 µL–4 mL | 10,000 rpm, 15 min at 4 °C |
NanoString technology, qPCR, 16S RNA sequencing | ↑miR-29a-3p and miR-141-3p ↓miR-16-5p, let-7b-5p, miR-451a ↑Rothia, Filifactor, Actinobacillus, Weeksellaceae, Ralstonia, Pasteurellaceae, Aggregatibacter ↓Tannerella, Moryella, TM7-3 |
[76] |
ADOS—Autism Diagnostic Observation Schedule; ADIR—Autism Diagnostic Interview-Revised; ASD—autism spectrum disorder; CARS—Childhood Autism Rating Scale; centrif—centrifugation CNV—copy number variation; CGH—comparative genome hybridization; DD—with developmental delay; Dg tool—diagnostic tool; DSM —Diagnostics and Statistical Manual; dur of sal—duration of salivation; F—female; M—male; miRNA—microRNA; NA—not applicable or mentioned in the text; ref—reference; SA—syndromic autism; SNP—single nucleotide polymorphism; TD—individuals with typical development; WES—whole-exome sequencing., ↓/↑—downregulated/upregulated in autism; NA—not applicable or mentioned in the text.