Table 1. Prenatal testing for mtDNA mutations.
| Pt | Reason for CVB | Screening mutation | Maternal mutation and heteroplasmy level | Result of CVB | Clinical outcome |
|---|---|---|---|---|---|
| 1 | Mother known mutation carrier | m.3243A>G | m.3243A>G (55% urine, 12% blood) | 68% m.3243A>Ga | Termination of pregnancy |
| 2 | Previously affected child | m.3243A>G | m.3243A>G not detected in blood/urine/buccal samples | No mutation detected | Pregnancy continued |
| 3 | Mother known mutation carrier | m.3243A>G | m.3243A>G (1% blood, 18% urine) | No mutation detected | Pregnancy continued |
| 4 | Maternal grandmother and brother affected | m.3243A>G | m.3243A>G not detected in blood/urine | No mutation detected | Baby clinically well; no mutation detected in blood DNA at 11 weeks |
| 5 | Previously affected child | m.8344A>G | m.8344A>G (35% blood, 35% urine) | 46% m.8344A>Ga | Data not available |
| 6 | Previously affected child | m.9176T>C | m.9176T>C not detected in blood/urine | 98% m.9176T>Ca | Termination of pregnancy |
| 7 | Previously affected child | m.9176T>C | m.9176T>C not detected in blood/urine | 9% m.9176T>Ca | Pregnancy continued |
| 8 | Previously affected child | m.8993T>G | m.8993T>G (73% blood) | 98% m.8993T>Ga | Termination of pregnancy; PM samples confirmed mutation levels 97% |
| 9 | Previously affected child | m.8993T>C | m.8993T>C (79% blood, 86% urine, 82% buccal) | 58% m.8993T>Ca | Pregnancy continued |
| 10 | Previously affected child | m.14453G>A | m.14453G>A not detected | No mutation detected | Clinically unaffected baby girl born |
| 11 | Previously affected child | m.13513A>G | m.13513G>A (45% blood) | No mutation detected | Baby clinically well; no mutation detected in blood DNA at 12 weeks |
| 12 | Maternal brother affected | m.11777C>A | m.11777C>A (30% blood, 36% urine, 43% buccal) | 46% m.11777C>Aa | Data not available |
| 13 | Mother known mutation carrier | m.10191T>C | m.10191T>C (2% blood, 16% urine) | No mutation detected | Pregnancy continued |
| 14 | Previously affected child | m.10158T>C | m.10158T>C (5% blood, 33% urine, 16% buccal) | 52% m.10158T>Ca | Data not available |
| 15 | Previously affected child | m.3688G>A | m.3688G>A (20% blood, 50% urine, 43% buccal) | 3% m.3688G>Aa | Clinically unaffected baby girl born |
| 16 | Previously affected child | m.11777C>A | m.11777C>A (18% blood, 32% urine, 20% buccal) | 54% m.11777C>Aa | Alive and well at 5 years |
| 17 | Previously affected child | Single large-scale mtDNA deletion | No deletion in mtDNA detected | mtDNA deletion not detected | Pregnancy continued |
Seventeen women referred for prenatal testing because of a personal or maternal family history of mtDNA disease, results of the prenatal test and clinical outcome where known.
Reference sequence: Revised Cambridge Reference Sequence;35 GenBank Reference NC_012920.1.
a
Information submitted to the publicly available MITOMAP database (http://www.mitomap.org/MITOMAP).