Italy bias (1 dizygotic twin normal fetuses pregnancy) reported Saker et al. Level IV N=12 fetus PCR and STR genotyping F508del 1 (8%) 7 (58%) 4 (33%) Unknown No clinical (2006) samples from and STRs outcomes Some risk of carrier couples reported France bias ARMS = amplification refractory mutation system; ASOH = allele-specific oligonucleotide hybridisation; CF = cystic fibrosis; CFTR = cystic fibrosis transmembrane conductance regulator; DGGE = denaturing gradient gel electrophoresis; DNA = deoxyribonucleic acid; FEB = fetal echogenic bowel; PCR = polymerase chain reaction; STR = short tandem repeats Table CFTR mutation test limitations, mutation identification errors and failure rates Study Evidence Population Test(s) Test limitations and resolutions Mutation identification Failure rate Country level and errors risk of bias Tomaiuolo, Level III-2 N=129 chromosomes CF(12) ARMS kit ARMS technology cannot distinguish 5 samples with homozygous Not reported Spina & from 85 DNA samples between heterozygous and point mutations were correctly Low risk of Castaldo from CF subjects with homozygous point mutations. identified but the CF(12) bias (2003) known mutations ARMS assay could not distinguish between the Italy heterozygous and homozygous state. Strom et al. Level III-2 N=7 confirmed CF DNA sequencing reactions This sequencing assay detects 991 of None reported Not reported (2003) patients with positive were performed with an ABI the 1,004 (98.7%) described mutations Low risk of sweat tests Prism Big Dye™ as of August 2002. USA bias Terminator v3.0 cycle 4 patients had 1 CF All but 2 of these mutations involve sequencing reaction kit mutation and 3 had no large deletions of CFTR and would not according to the mutations identified by be detectable by any sequencing manufacturer’s protocol. either the ACMG or assay. extended panel screening.
Italy bias (1 dizygotic twin pregnancy) normal fetuses reported Saker et al. (2006) France Level IV Some risk of bias N=12 fetus samples from carrier couples PCR and STR genotyping F508del and STRs 1 (8%) 7 (58%) 4 (33%) Unknown No clinical outcomes reported ARMS = amplification refractory mutation system; ASOH = allele-specific oligonucleotide hybridisation; CF = cystic fibrosis; CFTR = cystic fibrosis transmembrane conductance regulator; DGGE = denaturing gradient gel electrophoresis; DNA = deoxyribonucleic acid; FEB = fetal echogenic bowel; PCR = polymerase chain reaction; STR = short tandem repeats Table CFTR mutation test limitations, mutation identification errors and failure rates Study Country Evidence level and risk of bias Population Test(s) Test limitations and resolutions Mutation identification errors Failure rate Tomaiuolo, Spina & Castaldo (2003) Italy Level III-2 Low risk of bias N=129 chromosomes from 85 DNA samples from CF subjects with known mutations CF(12) ARMS kit ARMS technology cannot distinguish between heterozygous and homozygous point mutations. 5 samples with homozygous point mutations were correctly identified but the CF(12) ARMS assay could not distinguish between the heterozygous and homozygous state. Not reported Strom et al. (2003) USA Level III-2 Low risk of bias N=7 confirmed CF patients with positive sweat tests 4 patients had 1 CF mutation and 3 had no mutations identified by either the ACMG or extended panel screening. DNA sequencing reactions were performed with an ABI Prism Big Dye™ Terminator v3.0 cycle sequencing reaction kit according to the manufacturer’s protocol. This sequencing assay detects 991 of the 1,004 (98.7%) described mutations as of August 2002. All but 2 of these mutations involve large deletions of CFTR and would not be detectable by any sequencing assay. None reported Not reported
1216-MSAC-CA-CFTR.docx