Laboratory findings revealed low serum albumin (1.9 g/dL) and C3 levels (C3 25 mg/dL, n.v. 85–142 mg/dL; C4 20 mg/dL, n.v. 12–41 mg/dL), dyslipidaemia; ANA, ANCA and anti-DNA tested negative (Table 1). The gene discussed is C3; the disease is inherited lipid metabolism disorder.