Coexistence of Mosaic Marker Chromosome and Isodisomy 1 in Reproductive Failure: A Cytogenomic Case Report and Review of the Literature

To the best of our knowledge, this is the first reported case combining mosaic sSMC(1) and complete UPD1 in a phenotypically healthy woman with reproductive failure. The coexistence of these abnormalities likely reflects a postzygotic chromosomal rescue mechanism. These findings underscore the diagnostic value of integrated cytogenomic analyses in unexplained reproductive failure and subfertility.