Syndromic X-Linked Intellectual Disability Siderius Type, also known as siderius x-linked mental retardation syndrome, is related to intellectual developmental disorder, x-linked, syndromic, siderius type and x-linked intellectual disability, siderius type. An important gene associated with Syndromic X-Linked Intellectual Disability Siderius Type is PHF8 (PHD Finger Protein 8). Related phenotype is normal.