Screening of the entire coding region as well as the flanking intronic regions of the FANCG gene was undertaken in the seven patients.
Although a second pathogenic mutation was not identified in the FANCG gene of the remaining three patients (FA189, FA312 and FA402), the presence of large deletions, insertions or rearrangements cannot be excluded as the causal mutations in these patients.
Sequencing of the parents' FANCG genes for non-founder mutations has not been performed.
1636+1G>A mutation was discovered in intron 12 in the FANCG gene of patient FA465.
In the three patients in whom the second pathogenic mutation was not identified, large deletions, insertions or rearrangements in the FANCG gene cannot be excluded as the cause of FA.
Considering that only private mutations were identified in this study, it is possible to conclude that a second common pathogenic mutation in this population is unlikely to be found in the FANCG gene.
Full sequencing of the FANCG gene is then warranted in black FA patients who are found to be heterozygous for the FANCG founder mutation as a second mutation can sometimes be identified.