Ocular refraction: heritability and genome-wide search for eye morphometry traits in an isolated Sardinian population

• Published in: Human genetics Vol. 116; no. 3; pp. 152 - 159
• Main Authors: BIINO, Ginevra, PALMAS, Maria Antonietta, CORONA, Carla, PRODI, Dionigio, FANCIULLI, Manuela, SULIS, Roberta, SERRA, Antonina, FOSSARELLO, Maurizio, PIRASTU, Mario
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.02.2005; Berlin Springer Nature B.V; New York, NY
• Subjects: Adolescent; Adult; Age Factors; Aged; Biological and medical sciences; Biometrics; Biometry; Child; Child, Preschool; Classical genetics, quantitative genetics, hybrids; Cornea; Cornea - anatomy & histology; Eye - anatomy & histology; Female; Fundamental and applied biological sciences. Psychology; Gene loci; Genetic Linkage; Genetic Variation; Genetics of eukaryotes. Biological and molecular evolution; Genome, Human; Genomes; Glaucoma; Human; Humans; Italy; Male; Microsatellite Repeats; Middle Aged; Refraction, Ocular - genetics; Sex Factors; Italy; Italy, Sardegna; Eye; Visual system; Genetics; Population; Heritability; Genome; Morphometry
• ISSN: 0340-6717; 1432-1203
• DOI: 10.1007/s00439-004-1231-6

No genes influencing oculometric phenotypes have yet been identified, despite it being well known that eye morphometry is involved in refraction and that genetics may play an important role. We have therefore performed a heritability analysis and genome-wide search (GWS) of biometric ocular traits in an isolated Sardinian population, assessing the genetic contribution and identifying the associated genetic loci. A complete eye examination including refraction and ocular biometry measurements such as axial length (AL), anterior chamber depth (ACD) and corneal curvature (CC), was performed on 789 subjects. Heritability analysis was carried out by means of parent-offspring regression and variance component models. Univariate and bivariate linkage analysis was performed by using 654 microsatellite markers spanning the genome. CC showed a mean heritability of 57%. AL and ACD were found to have significantly different variances (P<0.01) in males and females, so that heritability was calculated separately for each sex. AL had an estimated heritability in females of 31% and in males of 60%, whereas ACD had an estimated heritability of 47% in females and of 44% in males. In the GWS, the most suggestive evidence of linkage was identified on chromosome 2 for AL (LOD 2.64), on chromosome 1 for ACD (LOD 2.32) and on chromosomes 7, 2 and 3 for CC (LOD 2.50, 2.44 and 2.34, respectively). High heritability of eye morphometry traits was thus revealed. The identified loci are the first linkage signals available in ocular biometry. Notably, the observed significant differences in parental transmission deserve further study.