Observed data
Embryo, foetus and child
Heteroplasmy in embryo biopsies and prenatal or postnatal samples
Comparisons between the transferred embryo and foetal or child tissue. The observations are not independent: several measurements may come from different tissues or time points in the same child.
Key finding. 30 comparisons from 16 foetuses and children. All comparisons classified here as discordant (C5e, C5f, C5g, C5h) concern one child whose postnatal samples were analysed using a different method. Here, discordant means an embryo result at or below 18% paired with a tissue result above 18%; this is a descriptive grouping, not a clinical threshold.
In 16 paired comparisons from 12 foetuses and children, the variant was not detected (ND) in either sample. These results are not exact measurements of zero.
A
B
Select a point to view its source and provenance. Embryo results reported as not detected appear in a separate ND band without a numerical axis. Exact numerical results are available in the table. Δ is expressed in percentage points. When only the tissue result is ND, Δ has a lower bound, shown by an open marker and an upward arrow. When only the embryo result is ND, Δ has an upper bound. ND → ND pairs are counted below the group and are not plotted at Δ = 0.
Comparisons: 30; foetuses and children: 16. C5 contributes 7 repeat measurements out of 30. Of 28 comparisons with low embryo heteroplasmy, 24 had low tissue heteroplasmy or a result reported as not detected. All comparisons classified here as discordant (C5e, C5f, C5g, C5h) concern one child whose postnatal samples were analysed using a different method. The embryo heteroplasmy level was low for 15 of 16 foetuses and children. In 14 of these, every tissue result was low or not detected. Results from different laboratories disagree for one child (C5).
Not plotted
- m.3243A>G, Treff et al., 2012: Not plotted: censored value
- m.10197G>A, Mizuguchi et al., 2025: Not plotted: excluded from the set of exact embryo–tissue pairs
- Sallevelt et al., 2017 doi:10.1093/humrep/dew356: m.14487T>C — two embryos with different heteroplasmy levels were transferred; it is not possible to establish which embryo resulted in the child.
- Steffann et al., 2014 doi:10.1016/j.celrep.2014.05.005: m.8344A>G — the tissue measured at birth is not specified.
- Monnot et al., 2011 doi:10.1002/humu.21417: Two embryos were transferred; it is not possible to establish which embryo resulted in the child.
- Hyslop et al., 2025 doi:10.1056/NEJMoa2415539: Table 1 reports test-blastomere and blood values for 10 children. Eight single-transfer pairs are included; double transfers cannot be linked to individual children.
Data table (32 records, including 30 matched embryo–tissue pairs from 16 foetuses and children)
n = 32
| ID | mtDNA variant | Embryo | Tissue | Value | Δ (tissue − embryo), pp | Maternal cluster | Source location | Source |
|---|---|---|---|---|---|---|---|---|
| C12a | m.3697G>A | 53.9% | Amniotic fluid | 49.7% | -4.2 | — | Table 3 | Ji et al., 2021 |
| C12b | m.3697G>A | 53.9% | Foetal tissues | 47.7% | -6.2 | — | Table 3 | Ji et al., 2021 |
| C1a | m.8993T>G | not detected | Amniotic fluid | not detected | ND → ND | — | Table 1 / Fig. 1 | Steffann et al., 2006 |
| C1b | m.8993T>G | not detected | Cord blood | not detected | ND → ND | — | Table 1 / Fig. 1 | Steffann et al., 2006 |
| C2 | m.8993T>G | 2.5% | Cord blood | 4% | 1.5 | — | Conference abstract; values via Castelluccio 2025 / Smeets 2023 (primary full text unavailable) | Thorburn et al., 2009 |
| C3 | m.8993T>G | not detected | Cord blood | not detected | ND → ND | — | Tables 1–2 | Sallevelt et al., 2013 |
| C5a | m.3243A>G | 12% | Buccal epithelium | 15% | 3 | — | Table 1; Treff 2012, Methods; Atlas worksheet «Figure 5», row 10 | Treff et al., 2012 |
| C6a | m.3243A>G | not detected | Buccal epithelium | not detected | ND → ND | — | Table 1 | Heindryckx et al., 2014 |
| C6b | m.3243A>G | not detected | Blood | not detected | ND → ND | — | Table 1 | Heindryckx et al., 2014 |
| C6c | m.3243A>G | not detected | Urine | not detected | ND → ND | — | Table 1 | Heindryckx et al., 2014 |
| C9a | m.8993T>G | not detected | Cord blood | not detected | ND → ND | — | Supplemental Table 3; p. 1526, Results of Clinical Application | Spath et al., 2021 |
| C9b | m.8993T>G | not detected | Buccal epithelium | not detected | ND → ND | — | Supplemental Table 3; p. 1526, Results of Clinical Application | Spath et al., 2021 |
| C5b | m.3243A>G | 12% | Buccal epithelium | not detected | ≥ -12 | — | Table 1 | Treff et al., 2012 |
| C5c | m.3243A>G | 12% | Urine | not detected | ≥ -12 | — | Table 1 | Treff et al., 2012 |
| C5d | m.3243A>G | 12% | Blood | below 10% | — | — | Table 1 | Treff et al., 2012 |
| C5e | m.3243A>G | 12% | Blood | 47% | 35 | — | — | Mitalipov et al., 2014 |
| C5f | m.3243A>G | 12% | Blood | 46% | 34 | — | — | Mitalipov et al., 2014 |
| C5g | m.3243A>G | 12% | Urine | 52% | 40 | — | — | Mitalipov et al., 2014 |
| C5h | m.3243A>G | 12% | Urine | 42% | 30 | — | — | Mitalipov et al., 2014 |
| C14a | m.3250T>C | 1.8% | Amniotic fluid | 1.5% | -0.3 | — | Supplementary Table S1 | Hu et al., 2026 |
| C14b | m.3250T>C | 1.8% | Cord blood | not detected | ≥ -1.8 | — | Supplementary Table S1 | Hu et al., 2026 |
| C14c | m.3250T>C | 1.8% | Blood | not detected | ≥ -1.8 | — | Supplementary Table S1 | Hu et al., 2026 |
| C14d | m.3250T>C | 1.8% | Buccal epithelium | not detected | ≥ -1.8 | — | Supplementary Table S1 | Hu et al., 2026 |
| C13 | m.10197G>A | <5% in each of the two transferred embryos; the exact level in the embryo that implanted is unknown | Amniotic fluid | The authors interpreted the variant as not detected: the 0.17% signal was below that in the control sample (0.28%) | — | — | Fig. 2A | Mizuguchi et al., 2025 |
| C15 | m.10158T>C | not detected | Blood | not detected | ND → ND | hyslop2025-10158 | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.10158T>C / Child 1; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C16 | m.10158T>C | not detected | Blood | not detected | ND → ND | hyslop2025-10158 | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.10158T>C / Child 2; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C17 | m.13094T>C | not detected | Blood | not detected | ND → ND | hyslop2025-13094 | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.13094T>C / single-transfer row; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C18 | m.3243A>G | not detected | Blood | not detected | ND → ND | hyslop2025-3243-23-a | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.3243A>G / single-transfer row 1; maternal urine 23%; separate carrier; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C19 | m.3243A>G | not detected | Blood | not detected | ND → ND | hyslop2025-3243-23-b | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.3243A>G / single-transfer row 2; maternal urine 23%; separate carrier; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C20 | m.8993T>G | not detected | Blood | not detected | ND → ND | hyslop2025-8993TG | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.8993T>G / Child 1; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C21 | m.8993T>G | not detected | Blood | not detected | ND → ND | hyslop2025-8993TG | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.8993T>G / Child 2; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |
| C22 | m.8993T>C | not detected | Blood | not detected | ND → ND | hyslop2025-8993TC | Table 1, PGT; Hyslop et al., 2025, Table 1, PGT, m.8993T>C / single-transfer row; <3% in day-3 test blastomere and newborn blood spot | Hyslop et al., 2025 |