Research
De novo 7p partial trisomy characterized by subtelomeric FISH and whole-genome array in a girl with mental retardation
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* Corresponding author: Lakshmi R Kandukuri lakshmi@ccmb.res.in
1 Department of Genetics, Dr. ALMPG. Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai - 600113, Tamil Nadu, India
2 Clinical Research Facility-Medical Biotechnology, Centre for Cellular and Molecular Biology Annex II, Uppal Road, Hyderabad - 500007, Andhra Pradesh, India
3 Genome Foundation, Centre for Cellular and Molecular Biology, Hyderabad-500007, India
4 Department of Medical Genetics, Institute of Obstetrics and Gynecology, Madras Medical College, Government Hospital for Women and Children, Egmore, Chennai - 600008, India
Molecular Cytogenetics 2011, 4:21 doi:10.1186/1755-8166-4-21
Published: 3 October 2011Abstract
Chromosome rearrangements involving telomeres have been established as one of the major causes of idiopathic mental retardation/developmental delay. This case of 7p partial trisomy syndrome in a 3-year-old female child presenting with developmental delay emphasizes the clinical relevance of cytogenetic diagnosis in the better management of genetic disorders. Application of subtelomeric FISH technique revealed the presence of interstitial telomeres and led to the ascertainment of partial trisomy for the distal 7p segment localized on the telomeric end of the short arm of chromosome 19. Whole-genome cytogenetic microarray-based analysis showed a mosaic 3.5 Mb gain at Xq21.1 besides the approximately 24.5 Mb gain corresponding to 7p15.3- > pter. The possible mechanisms of origin of the chromosomal rearrangement and the clinical relevance of trisomy for the genes lying in the critical regions are discussed.