Familial high myopia: evidence of an autosomal dominant mode of inheritance and genetic heterogeneity.
High myopia, defined as a refractive error inferior to -6 diopters, often appears as a familial disease. In order to precise its genetic background, we performed a segregation analysis on 32 French families (320 subjects including 120 individuals with clinical data) containing at least one high myopic person in their genealogy. Under the assumption of a two-alleles single gene model, the autosomal dominant transmission mode showed a much greater likelihood than the autosomal recessive mode, which therefore was rejected. From the segregation model obtained, a two-point linkage analysis was made on 18 families (107 subjects), among the 32 used for the segregation analysis. Different candidate loci were tested: collagen genes including Stickler syndrome types 1 and 2, proteoglycan genes, Marfan 1 syndrome and a Marfan like disorder localised in 3p24.2-p25. No evidence of linkage was found with any of the studied markers. In addition, the absence of linkage with chromosome 18p11.31 markers, a locus linked to familial high myopia in 6 North American families and 1 family of Chinese descent, demonstrated the genetic heterogeneity of the disease.
Naiglin
L
L
Laboratoire d'Immuno-Génétique moléculaire, Université Paul Sabatier, Hôpital Purpan, Pavillon Charles Lefebvre, Toulouse, France.
Clayton
J
J
Gazagne
C
C
Dallongeville
F
F
Malecaze
F
F
Calvas
P
P
D000483:Alleles; D020090:Chromosome Segregation; D005260:Female; D005799:Genes, Dominant; D018740:Genetic Heterogeneity; D008040:Genetic Linkage; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008297:Male; D009216:Myopia / Q000235:genetics*