Discerning non-disjunction in down syndrome patients by means of GluK1-(AGAT) n and D21S2055-(GATA) n microsatellites on chromosome 21.
Indian J Hum Genet
;
2012 May; 18(2): 204-216
Artigo
em Inglês
| IMSEAR
| ID: sea-143272
ABSTRACT
Introduction:
Down syndrome (DS), the leading genetic cause of mental retardation, stems from non-disjunction of chromosome 21.Aim:
Our aim was to discern non-disjunction in DS patients by genotyping GluK1-(AGAT) n and D21S2055-(GATA) n microsatellites on chromosome 21 using a family-based study design. Materials andMethods:
We have used a PCR and automated DNA sequencing followed by appropriate statistical analysis of genotype data for the present study Results andDiscussion:
We show that a high power of discrimination and a low probability of matching indicate that both markers may be used to distinguish between two unrelated individuals. That the D21S2055-(GATA) n allele distribution is evenly balanced, is indicated by a high power of exclusion [PE=0.280]. The estimated values of observed heterozygosity and polymorphism information content reveal that relative to GluK1-(AGAT) n [H obs =0.286], the D21S2055- (GATA) n [H obs =0.791] marker, is more informative. Though allele frequencies for both polymorphisms do not conform to Hardy-Weinberg equilibrium proportions, we were able to discern the parental origin of non-disjunction and also garnered evidence for triallelic (111) inheritance. The estimated proportion of meiosis-I to meiosis-II errors is 21 in maternal and 41 in paternal cases for GluK1-(AGAT) n , whereas for D21S2055-(GATA) n , the ratio is 21 in both maternal and paternal cases. Results underscore a need to systematically evaluate additional chromosome 21-specific markers in the context of non-disjunction DS.
Texto completo:
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Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
Polimorfismo Genético
/
Cromossomos Humanos Par 21
/
Humanos
/
Não Disjunção Genética
/
Família
/
Síndrome de Down
/
Repetições de Microssatélites
/
Técnicas de Genotipagem
Idioma:
Inglês
Revista:
Indian J Hum Genet
Ano de publicação:
2012
Tipo de documento:
Artigo
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