Background-Congenital microphthalmia (OMIM:309700) may occur in isolation o
r in association with a variety of systemic malformations. Isolated microph
thalmia 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 consa
nguineous family with autosomal recessive inheritance, the first locus for
isolated microphthalmia was mapped to chromosome 14q32. Eight members of th
is family underwent clinical examination to determine the nature of the mic
rophthalmia phenotype associated with this locus.
Results-All affected individuals in this family suffered from bilateral mic
rophthalmia in association with anterior segment abnormalities, and the bes
t 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 m
easured by Schiotz tonometry, was greatly elevated in many cases.
Conclusions-This combination of ocular defects suggests an embryological di
sorder involving tissues derived from both the neuroectoderm and neural cre
st. Other families with defects in the microphthalmia gene located on 14q32
may have a similar ocular phenotype aiding their identification.