Alternative titles; symbols
SNOMEDCT: 51886007, 85049009; ICD10CM: H53.55; ICD9CM: 368.53; ORPHA: 88629; DO: 11661;
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
Gene/Locus |
Gene/Locus MIM number |
|---|---|---|---|---|---|---|
| 7q32.1 | Colorblindness, tritan | 190900 | Autosomal dominant | 3 | OPN1SW | 613522 |
A number sign (#) is used with this entry because tritanopia is caused by heterozygous mutation in the OPN1SW gene (613522) on chromosome 7q32.
Tritanopia is an autosomal dominant disorder of human vision characterized by a selective deficiency of blue spectral sensitivity (Weitz et al., 1992).
The first report of tritan defects was that of Wright (1952) and related to a 'confusion chart' which had appeared in an article in a Netherlands illustrated paper, Picture Post, in 1951. Affected individuals lack blue and yellow sensory mechanisms while retaining those for red and green. Defective blue vision is characteristic.
Went and Pronk (1985) found 7 males with both tritan and red-green defects.
Kalmus (1955) concluded that tritanopia is autosomal dominant with incomplete manifestation.
Went and Pronk (1985) found tritan color vision defects in 79 persons in 6 families with autosomal dominant inheritance and wide variability in test results within families.
Went and Pronk (1985) estimated the frequency of tritanopia at 2 per 1,000; Kalmus (1955) had suggested a much lower frequency, about 1 in 20,000, and Wright (1952) had estimated the frequency in Great Britain as 'between 1 in 13,000 and 1 in 65,000, the higher frequency probably being the more likely.'
Using PCR and denaturing gradient gel electrophoresis (DGGE), Weitz et al. (1992) detected point mutations in the BCP gene (613522.0001, 613522.0002) in 5 individuals with tritanopia. The dominant inheritance of these mutations suggested that the aberrant gene products actively interfere with the viability or fidelity of blue-sensitive cone photoreceptors.
Kalmus (1965) concluded that there is an X-linked form of tritanopia.
Krill et al. (1971) suggested that congenital tritanopia and hereditary dominant optic atrophy are identical conditions, i.e., tritanopia is merely a manifestation of optic atrophy (165500). The view of Krill et al. (1971) was discredited by studies of Smith et al. (1973) and several other groups. Miyake et al. (1985) found that the blue cone electroretinogram permits differentiation of congenital tritanopia and dominantly inherited juvenile optic atrophy (DIJOA). The blue cone ERG was unrecordable in patients with congenital tritanopia but within the normal range in those with DIJOA.
Chiu, M. I., Zack, D. J., Wang, Y., Nathans, J. Murine and bovine blue cone pigment genes: cloning and characterization of two new members of the S family of visual pigments. Genomics 21: 440-443, 1994. [PubMed: 8088841] [Full Text: https://doi.org/10.1006/geno.1994.1292]
Gallagher, D. S., Jr., Womack, J. E., Baehr, W., Pittler, S. J. Syntenic assignments of visual transduction genes in cattle. Genomics 14: 699-706, 1992. [PubMed: 1330890] [Full Text: https://doi.org/10.1016/s0888-7543(05)80171-5]
Kalmus, H. The familial distribution of congenital tritanopia with some remarks on some similar conditions. Ann. Hum. Genet. 20: 39-56, 1955. [PubMed: 13249225] [Full Text: https://doi.org/10.1111/j.1469-1809.1955.tb01277.x]
Kalmus, H. Diagnosis and Genetics of Defective Colour Vision. Oxford: Pergamon Press (pub.) 1965. Pp. 58-59.
Krill, A. E., Smith, V. C., Pokorny, J. Further studies supporting the identity of congenital tritanopia and hereditary dominant optic atrophy. Invest. Ophthal. 10: 457-465, 1971. [PubMed: 5314165]
Miyake, Y., Yagasaki, K., Ichikawa, H. Differential diagnosis of congenital tritanopia and dominantly inherited juvenile optic atrophy. Arch. Ophthal. 103: 1496-1501, 1985. [PubMed: 3876823] [Full Text: https://doi.org/10.1001/archopht.1985.01050100072022]
Smith, D. P., Cole, B. L., Isaacs, A. Congenital tritanopia without neuroretinal disease. Invest. Ophthal. 12: 608-617, 1973. [PubMed: 4542649]
Weitz, C. J., Miyake, Y., Shinzato, K., Montag, E., Zrenner, E., Went, L. N., Nathans, J. Human tritanopia associated with two amino acid substitutions in the blue-sensitive opsin. Am. J. Hum. Genet. 50: 498-507, 1992. [PubMed: 1531728]
Went, L. N., Pronk, N. The genetics of tritan disturbances. Hum. Genet. 69: 255-262, 1985. [PubMed: 3872255] [Full Text: https://doi.org/10.1007/BF00293036]
Wright, W. D. The characteristics of tritanopia. J. Ophthal. Soc. Am. 42: 509-521, 1952.