Hypoceruloplasminemia‐related movement disorder without Kayser‐Fleischer rings is different from Wilson disease and not involved in ATP7B mutation

Abstract

To explore the relationship between hypoceruloplasminemia-related movement disorder (HCMD) without Kayser-Fleischer rings in Wilson disease (WD) and ATP7B gene mutation. Clinical feature, serum ceruloplasmin (CP), total serum copper, non-CP-bound serum copper (nCC), urine copper, and ATP7B gene sequence were investigated in 24 patients with HCMD. The patients with HCMD exhibited a long-term stable course of diseases. Serum CP in HCMD group (0.178 +/- 0.025 g/l) was lower than healthy control group (0.291 +/- 0.049 g/l, P < 0.05). Total serum copper in HCMD group was 0.578 +/- 0.284 microg/l and was lower than normal lower limit obviously (<or=0.80 microg/l). nCC was 0.143 +/- 0.073 microg/l and reached 29.18 +/- 19.61% of total serum copper. Urine copper in HCMD group was 303.82 +/- 225.68 microg/24 h and was higher than normal upper limit obviously (<or=70 microg/24 h). A heterozygous nonsense mutation of single nucleotide acid was found in one patient with spasmodic torticollis. Four single nucleotide polymorphisms (SNP) were found and their frequencies were not different between health control group and HCMD group. Four patients exhibited consistent sequence of ATP7B gene listed by GeneBank without any mutation and SNP. Hypoceruloplasminemia-related movement disorder without Kayser-Fleischer rings, which exhibits mild low serum CP and a long-term stability of disease course, is different from WD and not associated with ATP7B gene mutation. Further investigation of molecular biology should be encouraged.