X-linked reticulate pigmentary disorder shows more severe manifestations in hemizygous males compared to heterozygous females. Affected males have early onset of recurrent respiratory infections and failure to thrive resulting from inflammatory gastroenteritis or colitis. Patients also show reticular pigmentation abnormalities of the skin and may develop corneal scarring. Carrier females may be unaffected or have only pigmentary abnormalities along the lines of Blaschko (summary by Starokadomskyy et al., 2016).