PGT-mt Atlas

Observed data

Within individual embryos

Agreement in heteroplasmy levels between different parts of the same embryo

Panels A and B show the same blastocysts (n = 40). Panel C also includes 22 cleavage-stage embryos from one woman carrying m.3243A>G (Monnot et al., 2011; two blastomeres per embryo).

Key finding. Heteroplasmy levels are usually similar between samples from the same blastocyst. The median within-embryo range is 1.2 percentage points, or 2.2 percentage points for pathogenic variants (maximum 8 percentage points). In 76% of blastocysts with pathogenic variants, the range is 5 percentage points or less.

pathogenic variantsHV2 — control embryos

A. Samples from the same embryo

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B. Difference: analysed sample − clinical biopsy sample

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C. Within-embryo range

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Select a point to view its source and provenance. grey band — ±5 percentage points; an illustrative guide without a published source. Ranges calculated from three samples (11 embryos) and two samples (29) are not directly comparable; median — red bar.

Median range: 2.2 pp (21 blastocysts with pathogenic variants), 1 pp (HV2), 1.2 pp (all 40); cleavage stage — 1 pp (n = 22).

Data table (n = 40)

n = 40

EmbryomtDNA variantSourceTE biopsy sampleICMRemaining TECombined ICM+TE sampleRange (max − min), pp
Janssen2024_F20_E45m.3243A>GJanssen et al., 202449.6%—49.5%—0.1
Janssen2024_F20_E46m.3243A>GJanssen et al., 202467.1%—67.7%—0.6
Janssen2024_F20_E47m.3243A>GJanssen et al., 202475.6%—76.3%—0.7
Janssen2024_F20_E48m.3243A>GJanssen et al., 202440.8%—38.6%—2.2
Rubens_113HV2 polymorphismRubens et al., 202585%—84%—1
Rubens_114HV2 polymorphismRubens et al., 202582%—86%—4
Rubens_115HV2 polymorphismRubens et al., 202595%—96%—1
Rubens_116HV2 polymorphismRubens et al., 202591%91%88%—3
Rubens_117HV2 polymorphismRubens et al., 202554%53%56%—3
Rubens_118HV2 polymorphismRubens et al., 202583%—82%—1
Rubens_120HV2 polymorphismRubens et al., 202593%100%93%—7
Rubens_123HV2 polymorphismRubens et al., 202590%90%88%—2
Rubens_125HV2 polymorphismRubens et al., 202594%—93%—1
Rubens_126HV2 polymorphismRubens et al., 202595%—94%—1
Rubens_127HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_128HV2 polymorphismRubens et al., 2025100%100%100%—0
Rubens_129HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_130HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_131HV2 polymorphismRubens et al., 2025100%100%100%—0
Rubens_132HV2 polymorphismRubens et al., 2025100%100%100%—0
Rubens_134HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_135HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_136HV2 polymorphismRubens et al., 2025100%—100%—0
Rubens_55m.8344A>GRubens et al., 202568%76%——8
Rubens_56m.8344A>GRubens et al., 202570%—70%—0
Rubens_57m.8344A>GRubens et al., 202574%80%——6
Rubens_61m.8344A>GRubens et al., 202576%82%——6
Rubens_105m.8993T>CRubens et al., 202569%—73%—4
Tofilo_1m.14487T>CTofilo et al., 202611.4%12.2%12.9%—1.5
Tofilo_2m.14487T>CTofilo et al., 202699.6%99.6%100%—0.4
Tofilo_3m.14487T>CTofilo et al., 202612%——13.5%1.5
Tofilo_4m.14487T>CTofilo et al., 202692.3%——90%2.3
Tofilo_5m.14487T>CTofilo et al., 202673.2%72.3%78.7%—6.4
Tofilo_6m.14487T>CTofilo et al., 202613.5%11.3%11.7%—2.2
Treff_blastocyst_1m.3243A>GTreff et al., 201223.67%25%——1.33
Treff_blastocyst_2m.3243A>GTreff et al., 201281.67%81%——0.67
Treff_blastocyst_3m.3243A>GTreff et al., 201291.25%85%——6.25
Treff_blastocyst_4m.3243A>GTreff et al., 201288.33%91%——2.67
Treff_blastocyst_5m.3243A>GTreff et al., 201281.75%83.33%——1.58
Treff_blastocyst_6m.3243A>GTreff et al., 201236.33%39.33%——3
Additional data: 16 samples from one blastocyst (Hu et al., 2026) extended view

A blastocyst with 17.8% m.3250T>C in the biopsy sample was divided into 16 samples of 3–5 cells; the ICM was not isolated. These data are not plotted because variability among small cell samples is not directly comparable with variability among larger embryo fractions.

#CellsDepth, ×m.3250T>C, %Δ vs 17.8%
1TE/ICM (3)93,31418.10.3
2TE/ICM (3)92,97017.7-0.1
3TE/ICM (3)93,32916.9-0.9
4TE/ICM (3)92,75216.3-1.5
5TE/ICM (3)93,85218.70.9
6TE/ICM (5)95,63319.71.9
7TE/ICM (5)93,53220.32.5
8TE/ICM (5)95,18417.5-0.3
9TE/ICM (5)96,60220.42.6
10TE/ICM (5)97,20121.94.1
11TE/ICM (5)94,35614.7-3.1
12TE (3)94,81518.60.8
13TE (3)95,15616.9-0.9
14TE (3–5)94,11418.50.7
15TE (3–5)94,21817.5-0.3
16TE (5)93,08317.5-0.3