Human NR5A1 wild-type allele is located in the vicinity of 9q33 and is approximately 26 kb in length. This allele, which encodes steroidogenic factor 1 protein, is involved in the activation of transcription for genes that are associated with steroid processing. Mutations in the gene are a factor in both XY sex reversal with or without adrenal failure and adrenocortical insufficiency without ovarian defect. [ ]