Year : 1979 | Volume
: 27 | Issue : 4 | Page : 216--217
Genetic studies in corneal dystrophies
Prakash Kumar, P Siva Reddy, P Ranga Reddy, UVS Reddy, JP Murthy
S. D. Eye Hospital, Hyderabad, India
S. D. Eye Hospital, Hyderabad
|How to cite this article:|
Kumar P, Reddy P S, Reddy P R, Reddy U, Murthy J P. Genetic studies in corneal dystrophies.Indian J Ophthalmol 1979;27:216-217
|How to cite this URL:|
Kumar P, Reddy P S, Reddy P R, Reddy U, Murthy J P. Genetic studies in corneal dystrophies. Indian J Ophthalmol [serial online] 1979 [cited 2021 Jan 18 ];27:216-217
Available from: https://www.ijo.in/text.asp?1979/27/4/216/32636
Corneal dystrophies constitute one of the important groups of genetic disorders. Broadly they are divided into two major groups. The first group includes the congenital corneal dystrophies wherein the corneal manifestations are evident at birth or appear early in childhood. The other group consists of heredo-familial types which are further classified according to their nature and topographical distribution of lesions. In this group manifestations are not present at birth but appear more or less during second decade of life. Their distinctive features are bilaterality, symmetry, progressivity absence of newly formed vascular channels, their familial characters, evolution and mechanism of transmission.
A substantial number of pedigrees, showing affected sibships are available in the literature and mode of their transmission of the corneal dystrophies is established.
Materials and Methods
27 cases of corneal dystrophies were examined during 1975 to 1977. Detailed case history was record with special reference to family history (Pedigree analysis).
Sibs of patients also examined.
Figures in bracket: consanguinous.
Of the 11 familial cases 6 (54.5%) were males and 5 (45.5%) females. Among 16 sporadic cases majority (13-81%) were males. Out of 27 cases of corneal dystrophy 12 were in second decade and 15 in third.
Birth order: In majority of cases early para had shown greater incidence of corneal dystrophy.
Mode of inheritance: All cases of familial, granular and dystrophies showed recessive mode of inheritance.
It is a significant point of observation in our series of study that percentage incidence of macular corneal dystrophy was highest. 11 (40.7%) cases out of 27 were found to be familial and all these cases showed an autosomal recessive mode of inheritance. There were consanguinous marriages among familial cases (45.5%) which strongly suggests the recessive nature of the disease. Therefore prevention of cousin marriages among the affected family may help in reducing the incidence of disease.
From the literature it appears that granular corneal dystrophy inherited as autosomal dominant, but in the present study these cases presented as autosomal recessive. This may be explained on the basis of heterogencity among the local population.
The occurence of sporadic cases may be due to genetic (mutations) or non-genetics environmental factors etc.
Among the familial cases the sex ratio was equal ruling out the possibility of sex linked inheritance.
Age incidence among the cases were between 10-30 age group.
Cases with early para had greater incidence of disease suggesting an increased risk among them.