PURPOSE: to report a case of monozygotic monochorial diamniotic twins with discordant karyotypes. METHODS AND RESULTS: the pregnancy was achieved following a treatment cycle with intracytoplasmic sperm injection (ICSI) and preimplantation genetic screening (PGS) for chromosomes X, Y, 13, 16, 18, 21, 22. One embryo euploid for studied chromosomes was transferred. Prenatal ultrasonography revealed monozygotic twins. One fetus had growth retardation, multiple organ abnormalities and polyhydramnion. The other twin had normal ultrasound appearance. Delivery on week 29 of gestation resulted in the birth of two females, a stillborn twin with karyotype 45,XX,-13[12]/46,XX,r(13)[3] and a healthy twin with normal karyotype. CONCLUSIONS: the discordance in the twins' karyotypes originated from a mosaic embryo. Structural chromosomal abnormality of the affected twin could not be revealed using standard PGS investigation. Embryo splitting occurred probably due to apoptotic process in an early stage of embryo development. Apoptosis represents one of the possible mechanisms which can explain the embryo twinning process globally.
PURPOSE: to report a case of monozygotic monochorial diamniotic twins with discordant karyotypes. METHODS AND RESULTS: the pregnancy was achieved following a treatment cycle with intracytoplasmic sperm injection (ICSI) and preimplantation genetic screening (PGS) for chromosomes X, Y, 13, 16, 18, 21, 22. One embryo euploid for studied chromosomes was transferred. Prenatal ultrasonography revealed monozygotic twins. One fetus had growth retardation, multiple organ abnormalities and polyhydramnion. The other twin had normal ultrasound appearance. Delivery on week 29 of gestation resulted in the birth of two females, a stillborn twin with karyotype 45,XX,-13[12]/46,XX,r(13)[3] and a healthy twin with normal karyotype. CONCLUSIONS: the discordance in the twins' karyotypes originated from a mosaic embryo. Structural chromosomal abnormality of the affected twin could not be revealed using standard PGS investigation. Embryo splitting occurred probably due to apoptotic process in an early stage of embryo development. Apoptosis represents one of the possible mechanisms which can explain the embryo twinning process globally.
Authors: A Nieuwint; R Van Zalen-Sprock; P Hummel; G Pals; J Van Vugt; H Van Der Harten; Y Heins; K Madan Journal: Prenat Diagn Date: 1999-01 Impact factor: 3.050
Authors: Amin A Milki; Sunny H Jun; Mary D Hinckley; Barry Behr; Linda C Giudice; Lynn M Westphal Journal: Fertil Steril Date: 2003-03 Impact factor: 7.329