Males are more commonly affected than females in-

Most X-linked disorders are X-linked recessive and are characterized by the following features: They are transmitted by heterozygous female carriers only to sons, who of course are hemizygous for the X chromosome. Heterozygous females rarely express the full phenotypic change, because they have the paired normal allele; although one of the X chromosomes in females is inactivated, this process of inactivation is random, which typically allows sufficient numbers of cells with the normal expressed allele to emerge. An affected male does not transmit the disorder to sons, but all daughters are carriers. Sons of heterozygous women have one chance in two of receiving the mutant gene. (Robbins Basic Pathology,9th edition,pg no. 220)