title: Origin of nondisjunction in trisomy 8 and trisomy 8 mosaicism.
abstract: Causes of chromosomal nondisjunction is one of the remaining unanswered questions in human genetics. In order to increase our understanding of the mechanisms underlying nondisjunction we have performed a molecular study on trisomy 8 and trisomy 8 mosaicism. We report the results on analyses of 26 probands (and parents) using 19 microsatellite DNA markers mapping along the length of chromosome 8. The 26 cases represented 20 live births, four spontaneous abortions, and two prenatal diagnoses (CVS). The results of the nondisjunction studies show that 20 cases (13 maternal, 7 paternal) were probably due to mitotic (postzygotic) duplication as reduction to homozygosity of all informative markers was observed and as no third allele was ever detected. Only two cases from spontaneous abortions were due to maternal meiotic nondisjunction. In four cases we were not able to detect the extra chromosome due to a low level of mosaicism. These results are in contrast to the common autosomal trisomies (including mosaics), where the majority of cases are due to errors in maternal meiosis.
authors.affiliation: Department of Genetics, Institute of Child Health, Athens, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Karadima
authors.forename: M
authors.initials: M
authors.lastname: Bugge
authors.forename: P
authors.initials: P
authors.lastname: Nicolaidis
authors.forename: D
authors.initials: D
authors.lastname: Vassilopoulos
authors.forename: D
authors.initials: D
authors.lastname: Avramopoulos
authors.forename: M
authors.initials: M
authors.lastname: Grigoriadou
authors.forename: B
authors.initials: B
authors.lastname: Albrecht
authors.forename: E
authors.initials: E
authors.lastname: Passarge
authors.forename: G
authors.initials: G
authors.lastname: Annerén
authors.forename: E
authors.initials: E
authors.lastname: Blennow
authors.forename: N
authors.initials: N
authors.lastname: Clausen
authors.forename: A
authors.initials: A
authors.lastname: Galla-Voumvouraki
authors.forename: A
authors.initials: A
authors.lastname: Tsezou
authors.forename: S
authors.initials: S
authors.lastname: Kitsiou-Tzeli
authors.forename: J M
authors.initials: JM
authors.lastname: Hahnemann
authors.forename: J M
authors.initials: JM
authors.lastname: Hertz
authors.forename: G
authors.initials: G
authors.lastname: Houge
authors.forename: M
authors.initials: M
authors.lastname: Kuklík
authors.forename: M
authors.initials: M
authors.lastname: Macek
authors.forename: D
authors.initials: D
authors.lastname: Lacombe
authors.forename: K
authors.initials: K
authors.lastname: Miller
authors.forename: A
authors.initials: A
authors.lastname: Moncla
authors.forename: I
authors.initials: I
authors.lastname: López Pajares
authors.forename: P C
authors.initials: PC
authors.lastname: Patsalis
authors.forename: M B
authors.initials: MB
authors.lastname: Petersen
mesh_terms: D002648:Child; D002675:Child, Preschool; D002898:Chromosomes, Human, Pair 8; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009030:Mosaicism; D009630:Nondisjunction, Genetic; D014314:Trisomy