Segmental aneuploid hotspots identified across the genome concordant on reanalysis.

The aim of this study was to characterize a large set of full segmental aneuploidies identified in trophectoderm (TE) biopsies and evaluate concordance in human blastocysts. Full segmental aneuploid errors were identified in TE biopsies (n = 2766) from preimplantation genetic testing for aneuploid (PGT-A) cycles. Full segmental deletions (n = 1872; 66.1%) presented twice as many times as duplications (n = 939; 33.9%), mapped more often to the q-arm (n = 1696; 61.3%) than the p-arm (n = 847; 31.0%) or both arms (n = 223; 8.1%; P < 0.05), and were eight times more likely to include the distal end of a chromosome than not (P < 0.05). Additionally, 37 recurring coordinates (each ≥ 10 events) were discovered across 17 different chromosomes, which were also significantly enriched for distal regions (P = 4.1 × 10-56). Blinded concordance analysis of 162 dissected blastocysts validated the original TE PGT-A full segmental result for a concordance of 96.3% (n = 156); remaining dissected blastocysts were identified as mosaic (n = 6; 3.7%). Origin of aneuploid analysis revealed full segmental aneuploid errors were mostly paternally derived (67%) in contrast to whole chromosome aneuploid errors (5.8% paternally derived). Errors from both parental gametes were observed in 6.5% of aneuploid embryos when multiple whole chromosomes were affected. The average number of recombination events was significantly less in paternally derived (1.81) compared to maternally derived (3.81) segmental aneuploidies (P < 0.0001). In summary, full segmental aneuploidies were identified at hotspots across the genome and were highly concordant upon blinded analysis. Nevertheless, future studies assessing the reproductive potential of full (non-mosaic) segmental aneuploid embryos are critical to rule out potential harmful reproductive risks.

Word learning in linguistic context: Processing and memory effects.

During language acquisition, children exploit syntactic cues within sentences to learn the meanings of words. Yet, it remains unknown how this strategy develops alongside an ability to access cues during real-time language comprehension. This study investigates how on-line sensitivity to syntactic cues impacts off-line interpretation and recall of word meanings. Adults and 5-year-olds heard novel words embedded in sentences that were (1) consistent with an agent-first bias (e.g., "The blicket will be eating the seal"→"the blicket" is an agent), (2) required revision of this bias (e.g., "The blicket will be eaten by the seal"→"the blicket" is a theme), or (3) weakened this bias through a familiar NP1 (e.g., "The seal will be eating/eaten by the blicket"→"the seal" is an agent or theme). Across both ages, eye-movements during sentences revealed decreased sensitivity to syntactic cues in contexts that required syntactic revision. In children, the magnitude of on-line sensitivity was positively associated with the accuracy of learning after the sentence. Parsing challenges during the word-learning task also negatively impacted children's later memory for word meanings during a recall task. Altogether, these results suggest that real-time demands impact word learning, through interpretive failures and memory interference.