Macromelanosomes in X-linked ocular albinism.

Examination of clinically normal skin from four patients with X-linked ocular albinism of the Nettleship-Falls type by light and electron microscopy revealed the presence of macromelanosomes in some melanocytes and keratinocytes. Measuring up to 5 micron many of the abnormal melanosomes showed a concentrically laminated structure suggestive of a phasic growth pattern. Epidermis from three female carriers contained similar but fewer macromelanosomes. These findings indicate that skin biopsy could be of value not only in confirming the diagnosis of ocular albinism in affected males, but also to establish carrier status in asymptomatic females.