title: Karyotyping in retinoblastoma--a statistical approach.
abstract: OBJECTIVE
  Karyotype analysis in hereditary retinoblastoma is considered to be of marginal value in risk prediction due to uncertainties in the assessment of 13q14 deletions. However, it is a low cost genetic test for retinoblastoma in developing countries. In the present study, the results of karyotype analysis were refined by a statistical method to overcome limitations.
  
  
  METHODS
  Karyotype analysis was performed by trypsin-Giemsa banding and naked eye karyotyping for 33 bilateral, 25 unilateral and one regressed retinoblastoma patients. The percentage of metaphases with 13q14 deletions in each case was plotted on a scatter diagram. Normalization of the data was achieved by log transformation and the results were statistically analyzed by one-sample 't' test using SPSS version 9.0.
  
  
  RESULTS
  Seven samples had 13q14 deletion percentages above the cutoff value. One-sample 't' test showed significance (p< 0.001). By this method, two unilateral and five bilateral patients had 13q14 deletions, constituting 11.8 % of cases.
  
  
  CONCLUSIONS
  For accuracy, statistical analysis should be considered as an adjunct in karyotyping.
authors.affiliation: SNONGC Dept of Genetics and Molecular Biology, Medical Research Foundation, Chennai 600 006, Tamil Nadu, India.
authors.forename: Biju
authors.initials: B
authors.lastname: Joseph
authors.forename: Pradeep G
authors.initials: PG
authors.lastname: Paul
authors.forename: Anuradha
authors.initials: A
authors.lastname: Elamparithi
authors.forename: Joseph
authors.initials: J
authors.lastname: Roy
authors.forename: Authiappan
authors.initials: A
authors.lastname: Vidhya
authors.forename: Mahesh P
authors.initials: MP
authors.lastname: Shanmugam
authors.forename: Govindasamy
authors.initials: G
authors.lastname: Kumaramanickavel
mesh_terms: D002871:Chromosome Banding; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D006801:Humans; D007621:Karyotyping / Q000379:methods*; D019572:Retinal Neoplasms / Q000235:genetics*; D012175:Retinoblastoma / Q000235:genetics*; D013223:Statistics as Topic