title: Regional and ethnic distribution of beta thalassemia mutations and effect of consanguinity in patients referred for prenatal diagnosis.
abstract: OBJECTIVE
  To determine the regional and ethnic distribution of beta thalassemia mutation and the effect of consanguinity in patients referred for prenatal diagnosis of beta b-thalassemia and to target the high risk population for screening.
  
  
  METHODS
  Cross-sectional, analytical study.
  
  
  METHODS
  The study was conducted in Gentec Laboratory, Lahore, from January 2001 to December 2005.
  
  
  METHODS
  A total of 499 couples were referred to Gentec Lab., Lahore, from all over Pakistan for prenatal diagnosis of b-thalassemia. After counseling, chorionic villus sampling was done between 10-16 weeks of gestation. DNA analysis was done by Amplification Refractory Mutation System (ARMS) for type of mutation in the Armed Forces Institute of Pathology, Rawalpindi. Ethnicity, race and consanguineous relationship of parents was determined.
  
  
  RESULTS
  b-thalassemia was prevalent in Punjabis (60.7%) followed by Saraikees (25.5%). Castewise it was most frequent in Rajputs followed by Jatts, Arain, Sheikhs and Pathans. 56.7% of the couples were first cousins and 19.8% were relatives. The commonest mutations were Frameshift 8-9 (Fr8-9) 33.5%, Intervening Sequence 1-5 (IVS 1-5) 17.2%, Fr4142 - 8%, IVS 1-1 - 5.2%, Deletion 619 (Del 619) 4.2% and Codon 5 (Cd 5) - 4.2%. In samples sent for analysis, 53.1% turned out to be carriers (trait), 25.3% were diseased (thalassemia major) and 21.6% were normal. P-value of all results was less than 0.001.
  
  
  CONCLUSIONS
  In this series, the highest frequency was found in Punjabi Rajputs. The commonest mutation was Fr 8-9. Most parents were first cousins. Premarital thalassemia carrier testing can effectively reduce the disease.
authors: Department of Obs/Gynae, Lahore Medical and Dental College, Lahore. maimoonahafeez_pk@yahoo.com
authors: Maimoona
authors: M
authors: Hafeez
authors: Maleeha
authors: M
authors: Aslam
authors: Ayesha
authors: A
authors: Ali
authors: Yasmin
authors: Y
authors: Rashid
authors: Hussain
authors: H
authors: Jafri
mesh_terms: D003241:Consanguinity; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D009154:Mutation; D010154:Pakistan; D011247:Pregnancy; D011296:Prenatal Diagnosis; D017086:beta-Thalassemia / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*