Table 6. Proportion of patients with WD with normal ceruloplasmin levels in different regions.

Author	Country/time	Patients with Wilson’s disease
		Total number of patients	Patients with normal CP levels
Brewer GJ et al. [24]	USA/1992	89	8(11.2%)
Martins da Costa C [25]	United Kingdom/1992	17	3(17.6%)
Steindl P et al. [18]	Germany/1997	55	15(27.3%)
Merle U et al. [26]	Germany/2007	163	19(11.8))
Gheorghe L et al. [27]	Romania/2004	55	24(43.6%)
Müller T et al. [28]	Austria/2007	35	9(25.7%)
Manolaki N et al. [29]	Greece/2008	57	7(12.3%)
Nicastro E et al. [30]	Italy/2010	40	2(5.0%)
El-Karaksy H et al. [31]	Egypt/2011	54	1(1.9%)
Taly AB et al. [32]	India/2007	282	19(6.9%)
Rukunuzzaman MD [33]	Bangladesh/2015	100	27(27.0%)
Lee BH et al. [21]	Korea/2011	237	0(0.0%)
Mak CM et al. [4]	Hong Kong/2008	57	1(1.8%)
Liu Y et al. [23]	China/2015	77	2(2.6%)
Feng L et al. [22]	China/2016	126	0(0.0%)
This study	China/2017	297	3(1.0%)