Congenital hereditary non-conjugate hyperbilirubinemias include Gilbert’s syndrome, Crigler-Najjar type 1 and Crigler-Najjar type 2 syndromes (or Arias’ disease). They are caused by a hereditary deficiency of the enzyme - bilirubinuridine-5’-diphosphate glucuronosyltransferase (UGT1A1), involved in the glucuronization of bilirubin. The enzyme deficiency is due to mutations in the UGT1A1 gene, which provides UGT1A1 activity. Complete or almost complete loss of (Crigler-Najjar syndrome type 1) or decreased UGT1A1 activity (Gilbert’s syndrome and Crigler-Najjar syndrome type 2) lead to impaired conversion of bilirubin in the liver with the accumulation of unconjugated bilirubin in the blood. Syndromes are distinguished by the level of bilirubin in blood plasma, the reaction to the introduction of phenobarbital, the presence or absence of bilirubin glucuronides in bile.

Bacground. The optimization of Wilson’s disease (WD) diagnosis is one of the most disputable problem. Objective. The retrospective study of initial assessment findings under clinical suspicion for WD in 102 patients with the confirmed diagnosis. Material and methods. The results of laboratory tests and Kaiser-Fleischer rings (KF rings) identification under clinical suspicion for WD in 102 patients with the confirmed diagnosis. Results. At stage I, 17 patients (16.7%; 95% CI 10.7–25.1) were defined as having clinically definitive WD based on the combination of low serum ceruloplasmin and KF rings, 4 patients (3.9%; 95% CI 1.5–9.7) – based on the drop of ceruloplasmin level. After stage II, involving 24-hour urinary copper excretion evaluation, the rate of definitive diagnosis of WD reached 24,5% (95% CI 17.2 33.7). After stage III (genotyping for carriage of ATP7B gene mutations) – 56.9% (95% CI 47.2–66.0). Serum free copper increase was found in 54.9% (95% CI 41.4 67.7) of cases. Conclusions. Under clinical suspicion for WD, initial structured ophthalmological, laboratory and molecular-genetic assessment ensured the diagnosis of WD only in 56.9% (95% CI 56.9; 47.2–66.1). Frequent detection of serum free copper increase (54.9%, 95% CI 41.4 67.7) allows to use this test due to its greater availability as compared with 24-hour urinary copper excretion evaluation in WD diagnostics.