title: Germ-line transmission of trisomy 21: Data from 80 families suggest an implication of grandmaternal age and a high frequency of female-specific trisomy rescue.
authors.affiliation: Scientific Research Centre at Saint-Petersburg State Pediatric Medical Academy under the Federal Agency of Health Care and Social Development, St Petersburg, Russian Federation. kovaleva@robotek.ru.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Kovaleva