Indian Pediatrics

, Volume 47, Issue 5, pp 429–432

Phenotypic heterogeneity and parental origin of extra chromosome 21 in Down syndrome


    • Genetic Clinic, Department of PediatricsKEM Hospital
  • Tejasvi Chaudhari
    • Cytogenetics Division, Institute of ImmunohematologyIndian Council of Medical Research
  • Babu Rao Vundinti
    • Genetic Clinic, Department of PediatricsKEM Hospital
Short Communication

DOI: 10.1007/s13312-010-0078-2

Cite this article as:
Muranjan, M., Chaudhari, T. & Vundinti, B.R. Indian Pediatr (2010) 47: 429. doi:10.1007/s13312-010-0078-2


We compared the frequency of phenotypic features of 40 children with Down syndrome between individuals with a maternally or paternally derived extra chromosome 21, using quantitative FISH for comparing heteromorphisms of the nucleolar organizing region. Parental origin was determined in 90% of families. Hypotonia and craniofacial abnormalities were present in 90% or more individuals, irrespective of parental origin of chromosome 21. Congenital heart defects were more frequent in cases with a maternally derived extra chromosome 21. Imprinted gene(s) may contribute to the development of congenital heart defects in Down syndrome.


Congenital heart diseaseDown syndromeFluorescent in-situ hybridizationGenomic imprintingTrisomy 21
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© Indian Academy of Pediatrics 2010