Phenotype of autosomal recessive congenital microphthalmia mapping to chromosome 14q32
- David A R Bessanta,b,
- Khalid Anwarc,
- Shagufta Khaliqc,
- Abdul Hameedc,
- M Ismailc,
- Annette M Paynea,
- S Qasim Mehdic,
- Shomi S Bhattacharyaa
- aDepartment of Molecular Genetics, Institute of Ophthalmology, London, bMoorfields Eye Hospital, London, cDr A Q Khan Research Laboratories, Biomedical and Genetic Engineering Division, Islamabad, Pakistan
- David A R Bessant, Department of Molecular Genetics, Institute of Ophthalmology, London EC1V 9EL.
- Accepted 8 March 1999
Abstract
BACKGROUND Congenital microphthalmia (OMIM: 309700) may occur in isolation or in association with a variety of systemic malformations. Isolated microphthalmia may be inherited as an autosomal dominant, an autosomal recessive, or an X linked trait.
METHODS Based on a whole genome linkage analysis, in a six generation consanguineous family with autosomal recessive inheritance, the first locus for isolated microphthalmia was mapped to chromosome 14q32. Eight members of this family underwent clinical examination to determine the nature of the microphthalmia phenotype associated with this locus.
RESULTS All affected individuals in this family suffered from bilateral microphthalmia in association with anterior segment abnormalities, and the best visual acuity achieved was “perception of light”. Corneal changes included partial or complete congenital sclerocornea, and the later development of corneal vascularisation and anterior staphyloma. Intraocular pressure, as measured by Schiotz tonometry, was greatly elevated in many cases.
CONCLUSIONS This combination of ocular defects suggests an embryological disorder involving tissues derived from both the neuroectoderm and neural crest. Other families with defects in the microphthalmia gene located on 14q32 may have a similar ocular phenotype aiding their identification.
