A male infant with a 9.6 Mb terminal Xp deletion including the OA1 locus: Limit of viability of Xp deletions in males.

Males with deletions of or within Xp22.3-pter display variable contiguous gene syndromes including manifestations of Léri-Weill syndrome, chondrodysplasia punctata, mental retardation, ichthyosis, Kallmann syndrome, and ocular albinism. Herein, we report on a male infant with a large, cytogenetically visible, terminal Xp deletion defined by extensive FISH and STS marker analysis to encompass 9.6 Mb, and findings of all of the disorders mentioned above. His deletion approximates the largest Xp terminal deletion ever reported in a male individual. Since the extent of terminal Xp deletions viable in males is limited by the position of male lethal genes in Xp22.2 at about 10-11 Mb from the telomere, this patient falls into the category of the most severe male terminal Xp deletion phenotype.