Fig. 2: Maternal triploidy example.
a, Schematic of meiosis II error. Meiosis I error is shown in Extended Data Fig. 1. b, Maternal crossovers at chromosome 2 for a triploid fetus. The phase-informative sequence variants in the fetal genome are informative about transitions between the homologous chromosome and sister chromatid states along the genome. The phase-informative variants are limited to heterozygous (0/1) variants in the mother (1 is the HS allele). In the homologous state, the maternal variants are always present in the fetal genome (0/0/1), as both of the maternal haplotypes are present. In the sister state, the maternal variants are either absent (0/0/0) or have an allelic balance of 2/3 (0/1/1).
