Fig. 1: Distribution of fetal mutant loads. | Genetics in Medicine

Fig. 1: Distribution of fetal mutant loads.

From: A retrospective study on the efficacy of prenatal diagnosis for pregnancies at risk of mitochondrial DNA disorders

Fig. 1

(a) Distribution of fetal mutant loads according to type of mitochondrial DNA (mtDNA) mutation. Mutant loads were quantified for 76 fetuses of women carrying pathogenic mtDNA variants in mitochondrial transfer RNA (tRNA) (MT-TL1, and MT-TK; n = 37) or protein-coding (MT-ATP6, MT-CO2, and MT-ND; n = 39) genes. When more than one prenatal sample was available, mean fetal mutant load is shown. (b) Stability of pathogenic mtDNA variant loads across tissues in terminated pregnancies. In all, 26 pregnancies were terminated due to high fetal mutant loads, evaluated by amniotic fluid (AFS; white boxes) or chorionic villus (CVS; gray boxes) sampling. In 18 cases, analyses were carried out on fetal tissues (mean ± 1 SD, black boxes). The number of fetal tissues available for testing is indicated above each box. (c) Correlation between pre- and postnatal fetal mutant loads. Postnatal mutant loads were determined using cord blood sampled at birth for 29 children. Corresponding AFS (white boxes) or CVS mutant loads (gray boxes) are compared with cord blood levels (black boxes).

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