S. Oda et al., Detection of female carriers of congenital color-vision deficiencies by visual pigment gene analysis, CURR EYE R, 21(4), 2000, pp. 767-773
Purpose. Congenital color-vision deficiencies are frequent among males, 4.7
-8.0%, suggesting that female carriers are present at a frequency of 9-15%.
The purpose of this study was to determine whether carriers could be detec
ted by analysis of the visual pigment genes.
Methods. DNA from 29 males with congenital color-vision deficiencies, from
their mothers, and from 117 randomly-selected females was analyzed. The mos
t upstream genes, the downstream genes, and the most downstream genes in th
e red/green pigment gene arrays were amplified separately by PCR. Exon 5 of
each gene was analyzed by single-strand conformation polymorphisms (SSCP).
Results. Analysis of the visual pigment genes suggests that one of the 29 m
others examined is a female protan and two others are carriers of both prot
an and deutan defects. The remaining 26 mothers were confirmed to be carrie
rs of congenital color-vision deficiencies. Unusual patterns were observed
in 15 (13%) of the randomly-selected females; among them, 5 appeared to be
protan carriers and at least 4 to be deutan carriers.
Conclusions. Female carriers of congenital color-vision deficiencies can be
detected by analysis of the visual pigment genes. Since the proportion of
females showing unusual patterns was slightly higher than expected, some mu
st be false-positives and require more detailed examination.