title: Homozygosity mapping of a locus for a novel syndromic ichthyosis to chromosome 3q27-q28.
abstract: Ichthyosis is a heterogeneous group of skin disorders characterized by abnormal epidermal scaling. Occasionally, extracutaneous features are associated. A novel autosomal recessive ichthyosis syndrome is described here with scalp hypotrichosis, scarring alopecia, sclerosing cholangitis, and leukocyte vacuolization in two inbred kindreds of Moroccan origin. We also report the mapping of the diseased gene to a 21.2 cM interval of chromosome 3q27-q28. Homo zygosity for polymorphic markers has enabled us to reduce the genetic interval to a 16.2 cM region. Furthermore, comparison of mutant chromosomes in the two families has suggested a common ancestral mutant haplotype. This linkage disequilibrium has reduced the genetic interval encompassing the diseased gene to less than 9.5 cM maximum. Further study of additional families from the same geographic area will hopefully reduce the genetic interval as well as help in the cloning of the gene involved in this rare disorder.
authors.affiliation: Département de Génétique et Unité de Recherches sur les Handicaps Génétiques de l'Enfant INSERM U-393, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, 75743 Paris Cedex 15, France.
authors.forename: Lekbir
authors.initials: L
authors.lastname: Baala
authors.forename: Smaïl
authors.initials: S
authors.lastname: Hadj-Rabia
authors.forename: Dominique
authors.initials: D
authors.lastname: Hamel-Teillac
authors.forename: Michelle
authors.initials: M
authors.lastname: Hadchouel
authors.forename: Catherine
authors.initials: C
authors.lastname: Prost
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Leal
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jacquemin
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Sefiani
authors.forename: Yves
authors.initials: Y
authors.lastname: De Prost
authors.forename: Gilles
authors.initials: G
authors.lastname: Courtois
authors.forename: Arnold
authors.initials: A
authors.lastname: Munnich
authors.forename: Stanislas
authors.initials: S
authors.lastname: Lyonnet
authors.forename: Pierre
authors.initials: P
authors.lastname: Vabres
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015209:Cholangitis, Sclerosing / Q000235:genetics / Q000473:pathology; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D003241:Consanguinity; D005192:Family Health; D005260:Female; D018703:Founder Effect; D006720:Homozygote; D006801:Humans; D007039:Hypotrichosis / Q000235:genetics / Q000473:pathology; D007057:Ichthyosis / Q000235:genetics* / Q000473:pathology; D015603:Keratinocytes / Q000473:pathology; D007962:Leukocytes / Q000473:pathology; D008297:Male; D009018:Morocco; D010375:Pedigree; D012535:Scalp