Correlaciones genotipo-fenotipo en casos de síndrome de Down con trisomía parcial del cromosoma 21

Translated title of the contribution: Genotype-phenotype correlations in cases of Down syndrome with partial trisomy of HSA21

Marga Nadal, Xavier P. Estivill

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Down syndrome (DS) is the chief cause of mental retardation, affecting 1 in 700 births. In 99% of cases, DS is genetically associated with trisomy of chromosome 21 (HSA21), but it may be caused by partial trisomy of this chromosome, as described in about 40 published cases. Thanks to genetic mapping of HSA21, which has made all kinds of new probes available, and to the concomitant development of new genetic techniques such as FISH, such cases have been identified and characterised. The present study addresses six cases of DS caused by partial trisomy of HSA21. Two are caused by familial segregation of a translocation involving a segment of HSA21 and a segment of a different chromosome. The other four cases only involve HSA21: one involves a non-Robertsonian (21; 21) translocation and the other three involve interstitial duplication of HSA21. All cases were studied at a cytogenetic-molecular level and the break point was identified to gauge the extent of HSA21 trisomy by FISH. By identifying the break point in HSA21 and gathering detailed clinical data, it became possible to provide genetic counseling and even to establish a genotype-phenotype correlation in the six cases studied.

Original languageSpanish
Pages (from-to)19-24
Number of pages6
JournalSD Revista Medica Internacional sobre el Sindrome de Down
Volume5
Issue number2
Publication statusPublished - Jul 2001
Externally publishedYes

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Keywords

  • Chromosome 21
  • Down syndrome
  • FISH
  • Genotype-phenotype correlations
  • Partial trisomy

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

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