Heterozygous disruption of SOX6 does not result in elevations of HbF levels. (A) Conventional G-banding of chromosomes analyzed from the patients lymphocytes showing a balanced translocation with a karyotype of 46,XY,t(9;11)(q33.1;p15.1) that could be confirmed with fine mapping. (B) A schematic showing the resulting breakpoint (brkpt.) on chromosome 11 at position 16195,423 (from hg18) that disrupts the SOX6 gene. Domains are shown from SOX6, including the coiled-coil (c-c), CtBP2 binding, and HMG domains. (C) HbF content was measured using capillary electrophoresis (Capillarys 2; Sebia). No HbF was detected, which should be detectable in zone 7 (Z7). (D) The number of F cells were quantitated by flow cytometry (BD FACSCanto II; Becton Dickinson). A total of 50 000 erythrocytes were analyzed. The patient had 0.7% F cells (normal range: 0.4%-4%).