ATP7B and Wilson disease: Other nuances included that (4) screening for WD should be considered in any child/young adult presenting with unexplained new onset neuropsychiatric features, (5) ATP7B mutation analysis is recommended as a clinical diagnostic test to support the diagnosis of WD in a patient suspected to have WD, and (6) with 24-h urine copper tests, lower levels (> 40 μg/24 h) have been recommended especially for asymptomatic siblings but is less specific.