Keratoconus in Two Pairs of Identical Twins

Bechara, Samir Jacob; Waring, George O.; Insler, Michael S.

doi:10.1097/00003226-199601000-00016

Cited by 70 publications

(49 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…43,44 This concordance supports the evidence of heredity as a genetic factor in the etiology of KC. 43 In such cases, both autosomal dominant and recessive patterns of inheritance have been described. 31,35 Conversely, reports of monozygotic twins who were discordant for keratoconus have been published.…”

Section: Twin Studiessupporting

confidence: 82%

“…In general, KC studies have reported monozygotic twins concordant rather than discordant for KC, especially when twins were examined with modern computerized videokeratoscopy. [43][44][45] Twin studies showed a 54% concordance rate among monozygotic twins. 43,44 This concordance supports the evidence of heredity as a genetic factor in the etiology of KC.…”

Section: Twin Studiesmentioning

confidence: 99%

“…[43][44][45] Twin studies showed a 54% concordance rate among monozygotic twins. 43,44 This concordance supports the evidence of heredity as a genetic factor in the etiology of KC. 43 In such cases, both autosomal dominant and recessive patterns of inheritance have been described.…”

Section: Twin Studiesmentioning

confidence: 99%

See 2 more Smart Citations

The Epidemiology and Etiology of Keratoconus

Gordon‐Shaag¹,

Millodot²,

Shneor³

2012

International Journal of Keratoconus and Ectatic Corneal Diseases

View full text Add to dashboard Cite

Keratoconus is a noninflammatory disorder characterized by ectasia of the central or inferior portion of the cornea. This review presents the scant epidemiological information known to date and the factors believed to cause the development of the disease. They are the genetic factors for which evidence come from family studies, twin studies and genetic loci. There appears to be multiple genes causing a keratoconus phenotype with variable penetration. However, the genetic predisposition might not be enough; environmental factors, such as eye rubbing, atopy and UV exposure, may have a role in generating the disease.

show abstract

Section: Twin Studiessupporting

confidence: 82%

Section: Twin Studiesmentioning

confidence: 99%

See 1 more Smart Citation

The Epidemiology and Etiology of Keratoconus

Gordon‐Shaag¹,

Millodot²,

Shneor³

2012

International Journal of Keratoconus and Ectatic Corneal Diseases

View full text Add to dashboard Cite

show abstract

“…At least eight cases of keratoconus in both of homozygous twins have been reported. 7,15 There are, however, some reports of discordance also. 16 There have been many family studies suggesting a genetic cause.…”

Section: No Atopic Diseasementioning

confidence: 99%

Influence of ethnic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients

Georgiou

Funnell

Cassels-Brown

et al. 2004

Eye

265

194

View full text Add to dashboard Cite

Purpose To investigate the influence of ethnic origin on the incidence of keratoconus and the association of atopic diseases in patients with keratoconus. Methods Retrospective study of new patients referred to Dewsbury District General Hospital and diagnosed with keratoconus in a 6-year period between 1994 and 2000. The ethnic origin of the patient was defined as white, Asian, or other. Incidence was calculated from the catchment population of 176 774 (82% white people, 17% Asians, 1% others). t-Test, confidence intervals and v 2 tests were used to show statistical significance. Results A total of 74 cases of keratoconus were diagnosed over this period. Of these patients 29 (39%) were white and 45 (61%) were Asian. This equated to an incidence of keratoconus of 25 per 100 000 (1 in 4000) per year for Asians, compared with 3.3 per 100 000 (1 in 30 000) per year for white people (Po0.001). Asians presented significantly younger than white patients. The incidence of atopic disease was found to be significantly higher in white compared to Asian keratoconic patients. Conclusions Asians were significantly more likely to present with keratoconus. The Asian patients were mostly of Northern Pakistani origin. This community has a tradition of consanguineous, especially first-cousin marriages. The higher incidence in this population was highly suggestive of a genetic factor being significant in the aetiology. The incidence was higher than revealed by previous studies. Atopic disease was significantly less common in Asians compared to white people, supporting the theory of a different aetiology in these patients.

show abstract

“…5,7,10 Lastly, in the limited twin studies, 54% concordance rate among monozygotic twins was observed. 11,12 In the majority of keratoconus patients (in excess of 90%), the disorder is bilateral. In many instances, the disorder may start of a unilateral in nature, but over time, the other eye becomes affected.…”

mentioning

confidence: 99%

Genomewide linkage scan in a multigeneration Caucasian pedigree identifies a novel locus for keratoconus on chromosome 5q14.3-q21.1

Tang

Rabinowitz

Taylor

et al. 2005

Genetics in Medicine

106

View full text Add to dashboard Cite

Purpose: Keratoconus is a corneal dystrophy with an incidence of 1 in 2000 and a leading cause for cornea transplantation in Western developed countries. Both clinical observations and segregation analyses suggest a major role for genes in its pathogenesis. It is genetically heterogenous, most commonly sporadic, but inherited patterns with recessive or dominant modes have also been reported. We studied a four-generation autosomaldominant pedigree to identify disease loci for keratoconus. Methods: A two-stage genome-wide scan was applied to 27 family members. First linkage analysis was performed with 343 microsatellite markers along the 22 autosomal chromosomes at Ϸ10 cM density. This was followed by fine mapping at Ϸ2 cM density, in regions suggestive of linkage. Multipoint linkage analysis was performed using GeneHunter2. Results: Evidence of suggestive linkage from the initial scan was observed at the 82 to 112 cM region of chromosome 5q14.1-q21.3 with a maximum lod score (LOD) of 3.48 (penetrance ϭ 0.5). Fine mapping by testing an additional 11 microsatellite markers at 1 to 3 cM intervals revealed a narrower and higher peak (99 -119 cM) with LOD 3.53. By analysis of the recombination of haplotypes, the putative locus of keratoconus was further narrowed to a 6 cM region (8.

show abstract

Keratoconus in Two Pairs of Identical Twins

Cited by 70 publications

References 0 publications

The Epidemiology and Etiology of Keratoconus

The Epidemiology and Etiology of Keratoconus

Influence of ethnic origin on the incidence of keratoconus and associated atopic disease in Asians and white patients

Genomewide linkage scan in a multigeneration Caucasian pedigree identifies a novel locus for keratoconus on chromosome 5q14.3-q21.1

Contact Info

Product

Resources

About