OBJECTIVES:

WD is an autosomal recessive disorder of copper metabolism due to mutations in the ATP7B gene. Liver disease, neurologic symptoms, and psychiatric disorders can result from cumulative copper buildup in the liver, brain, and other tissues. Here we describe the clinical presentation of WD using performance outcome assessments.

METHODS:

In this observational study (NCT04531189), all participants completed physical therapist-administered measures: Gait quality assessment, Six-Minute Walk Test (6MWT), 4-Meter Gait Speed Test (4MGST), Berg Balance Test (BBT), grip strength, manual muscle test (MMT), fine motor function (9-Hole Peg Test [9-HPT] and portions of the Bruininks Oseretsky Test 2^nd edition [BOT-2]).

RESULTS:

Participants included 8 males and 9 females (range: 14-70 years old), all with confirmed WD. All walked without a device. 9/16 had a decrease in arm swing while walking (either bilaterally or one side). 7/16 walked with a narrowed base of support. On the 6MWT, all distances walked were well below what was predicted (55-81%). When walking at a maximum pace on the 4MGST, most walked faster than their peers (15/16). When walking at a comfortable pace, half were slightly slower than their peers. All had high BBT scores (49-56/56). 6/7 males and 4/9 females had dominant hand grip strength results >80% of predicted. 10/16 had MMT grades ≥4 out of 5. 6 had some muscles testing 3+ or less (primarily hip extensors, hip flexors, and abductors). Most males performed the 9-HPT as fast or faster than their peers with the dominant (4/7) and non-dominant hand (5/7). Most females were slower than their peers with the dominant (6/9) and non-dominant hand (6/9). Half completed a portion of BOT-2 without errors and with precision.

CONCLUSIONS:

Despite variability, all participants had impaired walking capacity. This study provides an in-depth characterization of WD and may help inform endpoint selection for future studies.