We further analyzed the frequencies of these three observed deletions by performing MLPA screening in 66 heterozygous patients and in 70 patients without any ATP7B identified mutations, as well as in 340 WD patients homozygous for 27 different mutations (S1 Table) located in the genomic regions of exons 14–16, 17–19 and 20. The gene discussed is ATP7B; the disease is Wilson disease.