COSMIDS MAP 2 INCONTINENTIA PIGMENTI TYPE-1 (IP1) TRANSLOCATION BREAKPOINTS TO A 180-KB REGION WITHIN A 1.2-MB YAC CONTIG

Incontinentia pigmenti (IF) is an X-linked dominant disorder of neuroe ctodermal development. Based on the observation of six unrelated femal es with clinical features of nonfamilial IP with constitutional de nov o reciprocal X;autosome translocations, a putative incontinentia pigme nti type 1 locus (IP1; MIM No. 308300) was localized to region Xp11.21 . Using available regional DNA markers, we constructed a yeast artific ial chromosome (YAC) contig that contained 1.2 Mb of distal Xp11.21 an d spanned two IP1 X-chromosomal breakpoints, This contig was used to g enerate a detailed molecular map of the region and identify three regi onal CpG islands. YAC-derived cosmids were used to clone and map the I P1 breakpoints to a 180-kb interval that was flanked by DNA markers DX S705 and DXS741. The physical map and genomic clones should facilitate the isolation and characterization of transcripts associated with the IP1 translocation breakpoints. (C) 1996 Academic Press, Inc.