title: Dizygotic twin boys born after ICSI with maternal meiosis I-derived free trisomy 21 in the first and multiple congenital anomalies in the second: chance or common aetiology?
abstract: We report on a pair of dizygotic twin boys born after ICSI. One twin was affected with maternal meiosis I-derived free trisomy 21. The other had multiple congenital malformations including a complex heart defect and oesophageal atresia. The advanced maternal age of 37 years predisposed for chromosome 21 meiosis I non-disjunction in twin A. Each of the multiple congenital anomalies in twin B has been described in trisomy 21. However, due to dizygosity demonstrated by a panel of molecular markers mapped on chromosome 21 as well as the results of investigations with 16 short tandem repeat markers localized on various other chromosomes, low level mosaicism or chimerism for this aneuploidy in twin B is unlikely. In addition, the twinning process, which by itself is associated with an increased rate of congenital malformations particularly affecting heart and oesophagus, might be responsible for the multiple congenital anomalies in twin B. Thus, in agreement with the results of several population-based studies from the literature, it appears unlikely that the micromanipulation of ICSI is causally responsible for the different anomalies found in these two boys.
authors.affiliation: Institute for Human Genetics, Department of Obstetrics and Gynecology and Children's Hospital, University of Leipzig, Leipzig, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Kotzot
authors.forename: Stephanie
authors.initials: S
authors.lastname: Schönekerl
authors.forename: Renaldo
authors.initials: R
authors.lastname: Faber
authors.forename: Dirk
authors.initials: D
authors.lastname: Hausen
authors.forename: Annegret
authors.initials: A
authors.lastname: Kujat
authors.forename: Ursula G
authors.initials: UG
authors.lastname: Froster
mesh_terms: D000015:Abnormalities, Multiple / Q000209:etiology*; D004314:Down Syndrome / Q000209:etiology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D020554:Sperm Injections, Intracytoplasmic / Q000009:adverse effects*; D014429:Twins, Dizygotic