A gene for isolated congenital ptosis maps to a 3-cM region within 1p32-p34.1.
Hereditary isolated congenital ptosis is an autosomal dominant disorder with incomplete penetrance characterized by a variable degree of unilateral or bilateral drooping of the upper eyelids. We report linkage of this disorder in a large family to markers on chromosome 1p. In our sample of 37 meioses, nine informative markers did not recombine with the disease. D1S2677 gave a maximum two-point LOD score of 8.8 on the assumption of 90% penetrance (theta = 0). D1S447/2733 and D1S1616 flank the disease locus, with two-point LOD scores of 5.6/6.6 (theta = .04) and 4.9 (theta = .05), respectively, defining a region of 2.8 cM. FISH of YACs containing flanking recombinant markers localizes the gene to chromosome 1p32-p34.1. These data establish a map location for an isolated congenital ptosis gene and demonstrate that this disorder is genetically distinct from other extraocular muscle-specific disorders such as congenital fibrosis of the extraocular muscles and blepharophimosis.
Engle
E C
EC
Department of Neurology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. engle@rascal.med.harvard.edu
Castro
A E
AE
Macy
M E
ME
Knoll
J H
JH
Beggs
A H
AH
D001763:Blepharoptosis / Q000235:genetics*; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D005260:Female; D005799:Genes, Dominant; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008126:Lod Score; D008297:Male; D010375:Pedigree; D011995:Recombination, Genetic
D005819:Genetic Markers