Mosaic variegated aneuploidy syndrome

12/01/2001 - "Genetic studies of uniparental disomy (UPD) employing many markers have helped geneticists to gain a better understanding of the molecular mechanisms underlying nondisjunction. "
12/01/2002 - "We suggest that the presence of both copies of the tumor suppressor gene in the cases with loss of heterozygosity of spanning markers and internal markers for that tumor suppressor gene could be explained by somatic recombination resulting in uniparental disomy, but not mitotic nondisjunction or deletion. "
04/01/1998 - "The patient was homoallelic for informative markers mapping near the chromosome 1 centromere, but he was heteroallelic for markers near both telomeres, establishing that the paternal uniparental disomy with partial isodisomy was caused by a meiosis II nondisjunction event. "
01/01/1998 - "This is consistent with a maternal meiosis I nondisjunction of chromosome 16 leading to maternal uniparental heterodisomy. "
11/01/1993 - "Patients with maternal disomy had advanced maternal age, suggesting that nondisjunction is part of the etiology of uniparental disomy. "

01/01/2012 - "The aims of the present study were to assess (1) the parental origin of trisomy 21 and the stage in which nondisjunction occurs and (2) the relationship between altered genetic recombination and maternal age as risk factors for trisomy 21. "
08/01/2009 - "Previous studies on relatively small samples of individuals with trisomy 21 caused by paternally derived errors have shown that: (1) advanced paternal age is not a risk factor for chromosome 21 nondisjunction (NDJ), (2) absence of recombination, but not the location of recombination is associated with paternal NDJ and (3) there is an excess of males among live-births with paternally derived trisomy 21. "
03/01/2007 - "Parental origin, nondisjunction, and recombination of the extra chromosome 21 in Down syndrome: a study in a sample of the Colombian population."
03/01/2005 - "Study of parental/meiotic origin of free trisomy 21 in nuclear families from Russia (70 cases), Ukraine (32 cases), and 22 from Germany revealed maternal nondisjunction in 77.3% (Germany), 93.8% (Ukraine), and 91.4% (Russia), paternal origin in 13.6%, 6.2%, and 8.6%, respectively. "
01/01/2003 - "Despite the great efforts contributed to studies on the trisomy 21 etiology, basic mechanisms of nondisjunction are still poorly understood. "

09/01/2009 - "Studies of human trisomies indicate a remarkable relationship between abnormal meiotic recombination and subsequent nondisjunction at maternal meiosis I or II. Specifically, failure to recombine or recombination events located either too near to or too far from the centromere have been linked to the origin of human trisomies. "
06/01/2004 - "Molecular studies of trisomies have demonstrated that the pattern of recombinaison was an important predisposing factor to meiotic nondisjunction. "
02/01/1996 - "Trisomy of human chromosome 18: molecular studies on parental origin and cell stage of nondisjunction."
03/01/1995 - "Trisomy 18: studies of the parent and cell division of origin and the effect of aberrant recombination on nondisjunction."
10/01/1994 - "Our studies suggest that there is little variation in the origin of nondisjunction among the five acrocentric trisomies and that there is no association between the origin of nondisjunction and the likelihood of survival to term of the trisomic conceptus. "

04/01/2008 - "We carried out meiotic studies in an infertile male to detect meiotic nondisjunction mechanisms leading to aneuploidy in spermatogenesis. "
01/01/2002 - "In this study, oocyte aneuploidy caused by both nondisjunction of bivalent chromosomes and predivision of univalent chromosomes was observed. "
11/01/1998 - "Although the etiology of human aneuploidy remains poorly understood, recent studies have elucidated certain fundamental correlates of meiotic nondisjunction, such as altered recombination. "
10/01/1994 - "The application of this technique to study the relationship between nondisjunction and chromosome pairing behavior in maternal-age-related aneuploidy is discussed."
01/01/1985 - "Even though aneuploidy is one of the worst afflictions of man, efforts to develop a mammalian test system for the study of induced nondisjunction have largely failed. "

03/01/1998 - "In a recent study Bugge et al and Kotzot et al reported that isochromosomes 18p originate mainly from maternal meiosis II nondisjunction, followed by misdivision. "
06/15/2004 - "Another monocentric case had 47 chromosomes with isochromosomes i(18p) and i(18q) formed by maternal postzygotic centromeric misdivision and segregation of both isochromosomes, or by meiosis II centromeric misdivision and nondisjunction (without recombination in meiosis I). "
07/22/2001 - "We speculated that the extra chromosome may have resulted from either nondisjunction of chromosome 9 followed by a U-type exchange and a crossing-over between different sister chromatids during maternal meiosis I and subsequent breakage and malsegregation during meiosis II, or nondisjunction during meiosis II followed by isochromosome formation in one of the two maternal chromosomes 9 and subsequent breakage."
07/01/2000 - "On the basis of C-banding pattern, it was hypothesized that these B chromosomes are isochromosomes that have arisen by means of centromere misdivision and chromatid nondisjunction. "
01/01/1999 - "Thus, independently of the chromosomal origin, in the majority of cases with additional euchromatic isochromosomes maternal meiosis nondisjunction is the initial step followed by centromeric misdivision. "