The X-linked form (OMIM:300200; http://www.ncbi.nlm.nih.gov/omim) is caused by a mutation or deletion of the gene dosage-sensitive sex reversal adrenal hypoplasia congenita critical region of the X chromosome, gene 1 (DAX-1; also called the adrenal hypoplasia, congenital homolog (AHCH) gene) on the X chromosome [3]. Here, NR0B1 is linked to alternating hemiplegia of childhood.