The QTL with the strongest association in the across-breed analyses was on BTA7 spanning from 52.92 to 53.09 Mb where the intronic variant rs38248541 within CYSTM1, which was also significantly associated with gestation length in the HF population, explained 0.75% of the genetic variance in gestation length (Table 5). The gene discussed is CYSTM1; the disease is hydrops fetalis.