Observed data
Cases
Published cases and case series, including heteroplasmy levels, sampled tissues and reported outcomes. Personal medical details are omitted; each numerical value retains its source attribution.
The primary source for each case is listed in the Source column: authors, publication and DOI.
n = 30
| mtDNA variant | Range across embryos | Transferred embryo | Foetal / child tissues | Source | Data type | Where the value comes from |
|---|---|---|---|---|---|---|
| m.8993T>G | 0–94/100% (2 embryos with no detectable variant; 1 embryo ~94–100%) | 0%; 0% / variant not detected | Amniotic fluid: not detected; cord blood: not detected | Steffann et al., 2006 doi:10.1136/jmg.2005.032326 published | Individual case or small series | Table and text of the primary publication |
| m.8993T>G | Not reported; only the transferred embryo is described | 2.5% | Cord blood: 4% | Thorburn et al., 2009 (no DOI) conference abstract | Individual case or small series | Conference abstract (Mol Genet Metab. 2009;98(1–2):5–6); no full text or PubMed record. Values were obtained from two independent reviews: Castelluccio 2025 (2.5% → cord blood 4%) and Smeets 2023 (2.5/2.5% → 3–5%) |
| m.8993T>G | 0–100%: the variant was detected in 3 of 20 embryos (30, 88 and 100%) and was not detected in the other 17 | 0%; 0%; 0% (three embryos transferred across two cycles) | Cord blood: 0% | Sallevelt et al., 2013 doi:10.1136/jmedgenet-2012-101172 published | Individual case or small series | Text of the primary publication (Results) |
| m.3243A>G | Cleavage-stage embryos: 1–70% (1–65%, 2–58% and 5–70% in three carriers); oocytes: 37–67%; zygotes: 0–66% | 4 embryos transferred to three patients; exact values for each woman were not extracted | No pregnancy | Sallevelt et al., 2013 doi:10.1136/jmedgenet-2012-101172 published | Individual case or small series | Text of the primary publication (Results) |
| m.3243A>G | 18–50% | No transfer / transfer not reported | Not applicable | Monnot et al., 2011 doi:10.1002/humu.21417 published | Individual case or small series | Table 3 of the primary publication |
| m.3243A>G | 0–75% | 5/5% and 13/16% (two blastomeres from each of two transferred embryos) | Amniotic fluid: 4±0%; placenta: 15±5%; cord blood: 5±1% | Monnot et al., 2011 doi:10.1002/humu.21417 published | Individual case or small series | Table 3 of the primary publication |
| m.3243A>G | 7–91% across embryo values; blastocysts: 12–90% | 12% | Buccal epithelium: 15% at 1 month (Treff et al., 2012). A commercial laboratory in the same study did not detect the variant in a buccal swab or urine sediment; blood results at 5 and 12 months were below 10% (Treff et al., 2012). Independent re-analysis of the same child using ARMS-qPCR at 6 weeks and 18 months found 47% and 46% in blood and 52% and 42% in urine (Mitalipov et al., 2014) | Treff et al., 2012 doi:10.1016/j.fertnstert.2012.07.1119 published Mitalipov et al., 2014 doi:10.1016/j.celrep.2014.05.004 published | Individual case or small series | Text of the primary publication (Abstract, Results) |
| m.3243A>G | 0–62% (means for 11 blastocysts; highest individual biopsy value 65.5%) | 0%; 0% / two blastocysts with no detectable variant | Buccal swab: 0%; blood: 0%; urine: 0% | Heindryckx et al., 2014 doi:10.1016/j.mito.2014.08.005 published | Individual case or small series | Table 1 of the primary publication (mean values for 11 blastocysts) |
| m.8344A>G | Not reported; transferred embryos: 53% and 59% | 53%; 59% | At birth: 63% (tissue not specified in the available summary) | Steffann et al., 2014 doi:10.1016/j.celrep.2014.05.005 published | Individual case or small series | Text of the primary publication |
| m.14487T>C | Approximately 5.75–100%; cycle 1 predominantly ~50–98%; cycle 2 ~6–100% | 5.4 and 6.1% in a 12-cell embryo; 12.2 and 12.3% in a 13-cell embryo (two blastomeres from each of two transferred embryos) | Cord blood: approximately 5% | Sallevelt et al., 2017 doi:10.1093/humrep/dew356 published | Individual case or small series | Text of the primary publication (~50–98%) and calculation from the primary data: mean of each blastomere pair |
| m.14487T>C | TE: 11.4–99.6% (11.4; 12.0; 13.5; 73.2; 92.3; 99.6) | No transfer | Not applicable | Tofilo et al., 2026 doi:10.1007/s10815-026-04012-y published | Individual case or small series | Original data reported by the authors |
| m.3697G>A | 15.2–100% | 31.7%; 53.9%; no live birth | Amniotic fluid: 49.7%; foetal tissues: 47.7±1.8% | Ji et al., 2021 doi:10.1007/s10815-021-02354-3 published | Individual case or small series | Text of the primary publication |
| m.8993T>G | 0–88.7% across the extracted values | No transfer (the blastocyst with no detectable variant was aneuploid) | Not applicable | Spath et al., 2021 doi:10.1016/j.fertnstert.2021.01.026 published | Individual case or small series | Supplemental Table 3 of the primary publication |
| m.8993T>G | 0% / variant not detected in any tested oocyte or embryo | 0% / variant not detected | Cord blood: not detected; buccal swab: not detected | Spath et al., 2021 doi:10.1016/j.fertnstert.2021.01.026 published | Individual case or small series | Supplemental Table 3 of the primary publication |
| m.10191T>C | 0% / m.10191T>C not detected in the reproductive samples tested | 0%; 0% / two euploid embryos with no variant detected were transferred in different cycles; no live birth after PGT | After PGT: no live birth. Subsequent spontaneous pregnancy: chorionic villus sample — 0% | Spath et al., 2021 doi:10.1016/j.fertnstert.2021.01.026 published | Individual case or small series | Supplemental Table 3 of the primary publication |
| m.3243A>G | 0–38.0% across embryos (arrested embryos: mean of two halves; highest individual half 39.6%); blastocyst/TE: 3.1–29.2% | 0%; 0% / two euploid embryos with no variant detected | No live birth | Spath et al., 2021 doi:10.1016/j.fertnstert.2021.01.026 published | Individual case or small series | Supplemental Table 3 of the primary publication; embryo values recalculated as the mean of two halves (Supplemental Table 3: embryo 17 — 39.6/36.4 → 38.0), consistent with the primary text (5.7–38.0%) |
| m.10197G>A | 1–96.5% (5/9 embryos <5%; 2/9 >95%; two intermediate results: 26–45% and 84–88%) | <5%; <5% / double transfer of two embryos with very low heteroplasmy; the exact level in the embryo that implanted is unknown | Amniotic fluid at 15 weeks: variant not detected. The 0.17% signal was below the control sample level of 0.28%; the authors noted the limitations of pyrosequencing at very low heteroplasmy levels | Mizuguchi et al., 2025 doi:10.1038/s41439-025-00311-5 published | Individual case or small series | Figure 2A of the primary publication: values digitised from the chart |
| m.3243A>G | 0–24% for values associated with live birth | 0%; 0%; 9% and 24% (double transfer, twins) | Two single-embryo transfers: blood — variant not detected (<3%). Twins: twin 1 — not tested; twin 2 — 7%. Embryo–child identity is not established | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.8993T>G | 0% | Variant not detected (<3%) | Blood: variant not detected (<3%) | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.8993T>C | 0% | 0% | Blood: variant not detected (<3%) | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.10158T>C | 0% | Variant not detected (<3%) | Blood: variant not detected (<3%) | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.13094T>C | 0% | 0% | Blood: variant not detected (<3%) | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.3688G>A | Variant not detected (<3%) and 5% | Variant not detected (<3%) and 5% (double transfer) | Blood: 7%; the transferred embryo cannot be matched to the child | Hyslop et al., 2025 doi:10.1056/NEJMoa2415539 published | Published single- and double-embryo transfers; individual embryo–child matching is possible only after single-embryo transfer. | Table 1 of the primary publication; individual values for transferred embryos. |
| m.8344A>G | 68–82% across TE/ICM/remaining TE samples | No transfer | Not applicable | Rubens et al., 2025 doi:10.1093/humrep/deaf050 published | Individual case or small series | Supplementary Table S1 of the primary publication |
| m.8993T>C | 69–73% | No transfer | Not applicable | Rubens et al., 2025 doi:10.1093/humrep/deaf050 published | Individual case or small series | Supplementary Table S1 of the primary publication |
| m.13094T>C | 71–92% | No transfer | Not applicable | Rubens et al., 2025 doi:10.1093/humrep/deaf050 published | Individual case or small series | Supplementary Table S1 of the primary publication |
| m.8993T>G | 100% | No transfer | Not applicable | Rubens et al., 2025 doi:10.1093/humrep/deaf050 published | Individual case or small series | Supplementary Table S1 of the primary publication |
| m.3243A>G | 38% in the extracted value; the complete range has not been verified in the current summary | No transfer | Not applicable | Rubens et al., 2025 doi:10.1093/humrep/deaf050 published | Individual case or small series | Supplementary Table S1 of the primary publication |
| Multiple variants | Not reported by woman in the current summary | Not reported; 5 pregnancies, 3 live births after PGT-mt | Not reported in the available main table | Mayeur et al., 2023 doi:10.1016/j.rbmo.2023.02.010 published | Cohort / aggregate data | Individual embryo values were not published in the primary source |
| m.3250T>C | 0–17.8%: 6 blastocysts (TE biopsy, 3–5 cells, days 5–7) — 17.8; 0; 0; 0; 1.8; 8.1%; 2 whole arrested embryos — 0; 0%. Mother: blood 20.2%, urine 21.7%, buccal epithelium 27.9%. | 1.8% (euploid blastocyst) | Amniotic fluid (18 weeks): 1.5%; cord blood: 0%; blood and buccal epithelium at 2 years: 0%; live birth | Hu et al., 2026 doi:10.1007/s10815-026-04041-7 published | Individual case or small series | Fig. 2 and Supplementary Table S1 of the primary publication; 0% = below the 1.0% threshold (NGS, depth ≥10 000×) |