title: Cytogenetic Analysis for Suspected Chromosomal Abnormalities; A Five Years Experience.
abstract: BACKGROUND
  Chromosomal abnormalities are the results of alterations in the number or structure of chromosomes causing significant human morbidity and mortality. They are responsible for a large proportion of miscarriages, developmental delay, disorders of sexual development, congenital malformations and mental retardation.
  
  
  OBJECTIVE
  The aim of this study was to describe the prevalence of different chromosomal abnormalities in North Indian patients referred for cytogenetic analysis.
  
  
  METHODS
  Total of 859 patients ranging from newborn to 37 years of age were referred to the division of genetics, Department of Paediatrics between 2010 and 2015, with a variety of clinical disorders; Down syndrome (DS), Turner's syndrome (TS) and Klinefelter syndrome; amenorrhea; ambiguous sex and multiple congenital malformations. Chromosomal analysis was performed on lymphocyte culture according to standard methods.
  
  
  RESULTS
  Of the 859 cases studied, 371 (43.1%) had chromosomal abnormalities. The most common autosomal abnormalities were DS 302 (81.4%) and sex chromosomal abnormalities were TS 51 (13.7%). Numerical abnormalities were accounted for 353 (41.0%) and structural abnormalities 18 (2.0%), respectively. Various other chromosomal anomalies were also reported.
  
  
  CONCLUSIONS
  We have reviewed the incidence and distribution of chromosomal abnormalities and found higher rate of chromosomal abnormalities 43.1% in the referred cases. Our data suggest that chromosomal analysis is important tool in the evaluation of genetic disorders and helps clinicians to provide accurate diagnosis and proper genetic counselling.
authors: Cytogeneticist, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Sunil Kumar
authors: SK
authors: Polipalli
authors: Research Associate, Department of Medicine, MAMC , New Delhi, India .
authors: Vijay Kumar
authors: VK
authors: Karra
authors: Student, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Ankur
authors: A
authors: Jindal
authors: Senior Research Fellow, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Madhavi
authors: M
authors: Puppala
authors: PhD Student, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Pratiksha
authors: P
authors: Singh
authors: Cytogenetic Technician, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Kanchan
authors: K
authors: Rawat
authors: Professor, Pediatrics Research & Genetic Lab, Department of Pediatrics, MAMC & Associated Lok Nayak Hospital , New Delhi, India .
authors: Seema
authors: S
authors: Kapoor
keywords: Aneuploidy; Autosomes; Cytogenetic analysis; Karyotypes; Sex chromosomes