{
  "abstract": "Background Wilson disease (WD) is a rare inherited metabolic disorder that is often underdiagnosed. Early diagnosis, before symptoms appear (pre-symptomatic WD), leads to a better response to treatment. For universal screening in children, spot urine tests are more practical than 24-hour urine collection. We previously determined reference ranges for spot urine copper excretion indices. In this study, we evaluated their screening performance in a prospective cohort of school children.Methods Spot urine samples were collected from 193 healthy children aged 4-11 years in this prospective cohort study conducted between 2022 and 2024. Of these, 176 children also provided a 24-hour urine sample. Urine copper levels were measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). We assessed previously established screening cut-off values: spot urine copper ≥0.5 µmol/L, copper to osmolality ratio ≥0.00085 μmol/mOsm, and copper to creatinine ratio ≥0.1 µmol/mmol, along with a new cut-off based on urine osmolality. Children whose urine samples exceeded any of these thresholds were recalled for second-tier tests, including blood ceruloplasmin and copper levels, and underwent diagnostic sequencing of the ATP7B gene.Results Ten children (5%) underwent second-tier testing. Two children exhibited very low ceruloplasmin levels and were genetically confirmed to have WD. Both were entirely asymptomatic at diagnosis. A spot urine copper concentration of ≥0.5 µmol/L demonstrated the best screening performance with excellent sensitivity. The strong correlation between spot urine copper concentration and 24-hour urine copper excretion (R 2=0.83, p<0.01) formed the basis for screening WD using spot urine copper. Additionally, one carrier was identified among the call-back group who had normal plasma ceruloplasmin.Conclusions In this small prospective screening cohort, two patients with WD and one carrier were identified. Spot urine copper is a useful biomarker for universal WD screening in school children, which may improve outcomes and fundamentally change the natural history of WD by enabling early detection and treatment before symptom onset.",
  "authors": [
    {
      "affiliations": [
        "Chinese University of Hong Kong, Hong Kong"
      ],
      "name": "Nelson Tang"
    },
    {
      "affiliations": [
        "CUHK Medical Center, Hong Kong"
      ],
      "name": "Joannie Hui"
    },
    {
      "affiliations": [
        "Chinese University of Hong Kong, Hong Kong"
      ],
      "name": "Iris Chan"
    },
    {
      "affiliations": [
        "Chinese University of Hong Kong, Hong Kong"
      ],
      "name": "Ronnie Chiang"
    },
    {
      "affiliations": [
        "Chinese University of Hong Kong, Hong Kong"
      ],
      "name": "Amy Wang"
    },
    {
      "affiliations": [
        "Hong Kong Children Hospital, Hong Kong"
      ],
      "name": "Kiran Belaramani"
    },
    {
      "affiliations": [
        "Chinese University of Hong Kong, Hong Kong"
      ],
      "name": "Albert Martin Li"
    },
    {
      "affiliations": [
        "Hong Kong Children Hospital, Hong Kong"
      ],
      "name": "Cheuk-Wing Fung"
    },
    {
      "affiliations": [
        "Hong Kong Children Hospital, Hong Kong"
      ],
      "name": "Anne Kwok"
    }
  ],
  "title": "IDDF2026-ABS-0178 Prospective screening of Wilson disease in primary school children using spot urine",
  "uid": "3a840b6c-0093-54b4-a162-5ab5e074767a"
}