FOXO1/FKHR (C9]

The forkhead transcription factor gene, FOXL2 located in blepharophimosis-ptosis-epicanthus inversus syndrome(BPES) critical region on chromosome 3q23. Consistent with an involvement in BPES, FOXL2 is selectively expressed in the mesenchyme of developing mouse eyelids and in adult ovarian follicles; in adult humans, it appears predominantly in the ovary. FOXL2 haploinsufficiency may cause BPES types I and II by the effect of a null allele and a hypomorphic allele, respectively. Furthermore, in a fraction of the BPES patients the genetic defect does not reside within the coding region of the FOXL2 gene and may be caused by a position effect. FOXL2 mutations can also cause gonadal dysgenesis or premature ovarian failure(POF) in women, as well as eyelid/forehead dysmorphology in both sexes.