ABCB4 and Becker muscular dystrophy: At age 13, he was diagnosed Becker muscular dystrophy carrying with the causative mutation in gene DMD (chrX:32,841,413–32,862,977, Hemizygous mutation), and gene testing showed the comorbid mutations of ABCB4(chr7:87041219, heterozygous mutation) and DSC2(chr18:28659938, heterozygous mutation).