Isochromosomes 12p and 9p: parental origin and possible mechanisms of formation.
Eur J Hum Genet
; 6(2): 140-4, 1998.
Article
em En
| MEDLINE
| ID: mdl-9781058
ABSTRACT
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. In order to determine if there is a common mechanism for isochromosome formation, three cases with mosaicism for an additional isochromosome 12p and three cases with tetrasomy 9p were studied. Two probands with isochromosomes 12p and the three cases with isochromosome 9p showed 3 alleles (two different maternal alleles and one paternal allele) at several loci mapping to distal 12p and 9p, respectively. Maternal heterozygosity for distal markers was reduced to homozygosity for markers closer to the centromere in both i(12p) cases and in one i(9p) case. For one patient with isochromosome 12p, the maternal band was clearly stronger than the paternal one at some loci, but two distinct maternal alleles were never seen. For one foetus and the patient with tetrasomy 9p, distal markers showed maternal heterozygosity. All proximal markers were not informative in these two i(9p) cases. Our findings indicate common features in different autosomal isochromosomes the origin of the isochromosomes analysed in predominantly maternal; and a common mechanism appears to underlie their formation, namely due to meiosis II nondisjunction followed by a rearrangements leading to duplication of the short and loss of the long arm.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromossomos Humanos Par 9
/
Cromossomos Humanos Par 12
/
Isocromossomos
Limite:
Adult
/
Child, preschool
/
Humans
/
Male
Idioma:
En
Revista:
Eur J Hum Genet
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Suíça