PURPOSE. To map the gene for autosomal dominant cataracts (ADC) in an Ameri
can white family of European descent.
METHODS. Ophthalmic examinations and linkage analyses using a variety of po
lymorphisms were performed; two-point lod scores calculated.
RESULTS. Affected individuals (14 studied) exhibited variable expressivity
of embryonal nuclear opacities based on morphology, location within the len
s, and density. This ADC locus to 12q13 was mapped on the basis of statisti
cally significantly positive lod scores and no recombinations (theta(m) = t
heta(f) = 0) with markers D12S368, D12S270, D12S96, D12S359, D12S1586, D12S
312, D12S1632, D12S90, and D12S83; assuming full penetrance, a maximum lod
score of 4.73 was calculated between the disease locus and D12S90.
CONCLUSIONS. The disease in this family represents the first ADC locus on c
hromosome 12; major intrinsic protein of lens fiber (MIP) is a candidate ge
ne.