Tritanopia is an autosomal dominant disorder of human vision characterized by a selective deficiency of blue spectral sensitivity (Weitz et al., 1992).

An anomaly in the ability to discriminate between or recognize colors.

A form of colorblindness in which only two of the three fundamental colors can be distinguished due to a lack of one of the retinal cone pigments.

Tritanopia is an autosomal dominant disorder of human vision characterized by a selective deficiency of blue spectral sensitivity (Weitz et al., 1992).

Autosomal dominant optic atrophy is characterized by an insidious onset of visual impairment in early childhood with moderate to severe loss of visual acuity, temporal optic disc pallor, color vision deficits, and centrocecal scotoma of variable density (Votruba et al., 1998). Some patients with mutations in the OPA1 gene may also develop extraocular neurologic features, such as deafness, progressive external ophthalmoplegia, muscle cramps, hyperreflexia, and ataxia; see 125250. There appears to be a wide range of intermediate phenotypes (Yu-Wai-Man et al., 2010). Yu-Wai-Man et al. (2009) provided a detailed review of autosomal dominant optic atrophy and Leber hereditary optic neuropathy (LHON; 535000), with emphasis on the selective vulnerability of retinal ganglion cells to mitochondrial dysfunction in both disorders. Genetic Heterogeneity of Optic Atrophy Also see optic atrophy-2 (OPA2; 311050), mapped to chromosome Xp11.4-p11.21; OPA3 (165300), caused by mutation in the OPA3 gene (606580) on chromosome 19q13; OPA4 (605293), mapped to chromosome 18q12.2-q12.3; OPA5 (610708), caused by mutation in the DNM1L gene (603850) on chromosome 12p11; OPA6 (258500), mapped to chromosome 8q21-q22; OPA7 (612989), caused by mutation in the TMEM126A gene (612988) on chromosome 11q14; OPA8 (616648), mapped to chromosome 16q21-q22; OPA9 (616289), caused by mutation in the ACO2 gene (100850) on chromosome 22q13; OPA10 (616732), caused by mutation in the RTN4IP1 gene (610502) on chromosome 6q21; OPA11 (617302), caused by mutation in the YME1L1 gene (607472) on chromosome 10p12; OPA12 (618977), caused by mutation in the AFG3L2 gene (604581) on chromosome 18p11; OPA13 (165510), caused by mutation in the SSBP1 gene (600439) on chromosome 7q34; OPA14 (620550), caused by mutation in the MIEF1 gene (615497) on chromosome 22q13; OPA15 (620583), caused by mutation in the MCAT gene (614479) on chromosome 22q13; and OPA16 (620629), caused by mutation in the MECR gene (608205) on chromosome 1p35.

OPA5 is an autosomal dominant form of nonsyndromic optic atrophy, manifest as slowly progressive visual loss with variable onset from the first to third decades. Additional ocular abnormalities may include central scotoma and color vision defects. The pathogenesis is related to defective mitochondrial fission (summary by Gerber et al., 2017). For a discussion of genetic heterogeneity of optic atrophy, see OPA1 (165500).

Any retinitis pigmentosa in which the cause of the disease is a mutation in the NR2E3 gene.

Syndromic optic atrophy, also known as DOA+ syndrome, is a neurologic disorder characterized most commonly by an insidious onset of visual loss and sensorineural hearing loss in childhood with variable presentation of other clinical manifestations including progressive external ophthalmoplegia (PEO), muscle cramps, hyperreflexia, and ataxia. There appears to be a wide range of intermediate phenotypes (Yu-Wai-Man et al., 2010).

Progressive retinal dystrophy due to retinol transport defect is a rare, genetic, metabolite absorption and transport disorder characterized by progressive rod-cone dystrophy, usually presenting with impaired night vision in childhood, progressive loss of visual acuity and severe retinol deficiency without keratomalacia. Association with ocular colobomas, severe acne and hypercholesterolemia has been reported.

Cone-rod dystrophy is a group of related eye disorders that causes vision loss, which becomes more severe over time. These disorders affect the retina, which is the layer of light-sensitive tissue at the back of the eye. In people with cone-rod dystrophy, vision loss occurs as the light-sensing cells of the retina gradually deteriorate.\n\nThe first signs and symptoms of cone-rod dystrophy, which often occur in childhood, are usually decreased sharpness of vision (visual acuity) and increased sensitivity to light (photophobia). These features are typically followed by impaired color vision (dyschromatopsia), blind spots (scotomas) in the center of the visual field, and partial side (peripheral) vision loss. Over time, affected individuals develop night blindness and a worsening of their peripheral vision, which can limit independent mobility. Decreasing visual acuity makes reading increasingly difficult and most affected individuals are legally blind by mid-adulthood. As the condition progresses, individuals may develop involuntary eye movements (nystagmus).\n\nThere are more than 30 types of cone-rod dystrophy, which are distinguished by their genetic cause and their pattern of inheritance: autosomal recessive, autosomal dominant, and X-linked. Additionally, cone-rod dystrophy can occur alone without any other signs and symptoms or it can occur as part of a syndrome that affects multiple parts of the body.

Congenital stationary night blindness type 1I (CSNB1I) is characterized by night blindness from infancy or early childhood. Visual acuity is preserved, but some patients have color vision and/or visual field defects. Older patients may show retinitis pigmentosa-like retinal degeneration (Stunkel et al., 2018).

Chromosome 16q12 duplication syndrome is characterized by early-onset progressive cone dystrophy, with early blue cone involvement. Patients report reduced visual acuity in the first decade of life, as well as difficulty differentiating colors, photophobia, and reduced night vision (Kohl et al., 2021). Tritanopia can also be caused by heterozygous mutation in the OPN1SW gene (613522) on chromosome 7q32 (see 190900).