OBJECTIVES: To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 25 June 2015.Date of latest search of all other sources: 10 December 2014.
SELECTION CRITERIA: Any randomised or quasi-randomised control trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care.
DATA COLLECTION AND ANALYSIS: We identified 19 papers, describing 13 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.
MAIN RESULTS: No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.
AUTHORS' CONCLUSIONS: As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.
OBJECTIVES: To assess the effectiveness of systematic preconception genetic risk assessment to improve reproductive outcomes in women and their partners who are identified as carriers of thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease in healthcare settings when compared to usual care.
SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Registers. In addition, we searched for all relevant trials from 1970 (or the date at which the database was first available if after 1970) to date using electronic databases (MEDLINE, Embase, CINAHL, PsycINFO), clinical trial databases (National Institutes of Health, Clinical Trials Search portal of the World Health Organization, metaRegister of controlled clinical trials), and hand searching of key journals and conference abstract books from 1998 to date (European Journal of Human Genetics, Genetics in Medicine, Journal of Community Genetics). We also searched the reference lists of relevant articles, reviews and guidelines and also contacted subject experts in the field to request any unpublished or other published trials.Date of latest search of the registers: 20 June 2017.Date of latest search of all other sources: 16 November 2017.
SELECTION CRITERIA: Any randomised or quasi-randomised controlled trials (published or unpublished) comparing reproductive outcomes of systematic preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease when compared to usual care.
DATA COLLECTION AND ANALYSIS: We identified 25 papers, describing 16 unique trials which were potentially eligible for inclusion in the review. However, after assessment, no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were found.
MAIN RESULTS: No randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis and Tay-Sachs disease were included. One ongoing trial has been identified which may potentially eligible for inclusion once completed.
AUTHORS' CONCLUSIONS: As no randomised controlled trials of preconception genetic risk assessment for thalassaemia, sickle cell disease, cystic fibrosis, or Tay-Sachs disease were found for inclusion in this review, the research evidence for current policy recommendations is limited to non-randomised studies.Information from well-designed, adequately powered, randomised trials is desirable in order to make more robust recommendations for practice. However, such trials must also consider the legal, ethical, and cultural barriers to implementation of preconception genetic risk assessment.
METHODS: In this study, we examined 31 patients for TSD-causing mutations using PCR, followed by restriction enzyme digestion.
RESULTS: Molecular genetics analysis of DNA from 23 patients of TSD revealed mutations that has been previously reported, including four-base duplications c.1274_1277dupTATC in exon 11 and IVS2+1G>A, deletion TTAGGCAAGGGC in exon 10 as well as a few novel mutations, including C331G, which altered Gln>Glu in HEXB, A>G, T>C, and p.R510X in exon 14, which predicted a termination codon or nonsense mutation.
CONCLUSION: In conclusion, with the discovery of these novel mutations, the genotypic spectrum of Iranian patients with TSD disease has been extended and could facilitate definition of disease-related mutations.