Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0, 4-0, 5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6-8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.
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PMID:[Foveolar aplasia in tyrosinase-positive oculocutaneous albinisim (author's transl)]. 82 41

A 56-year-old woman with tyrosinase-negative oculocutaneous albinism complained of gradually decreasing vision in the left eye. Her visual acuity was 20/300 in the right eye and hand motion in the left eye. She had pink skin and white hair and cilia. On examination, bilateral hypopigmented irides, an opaque lens in the left eye, a hypopigmented fundus in the right eye, and nystagmus were found. An extra-capsular cataract extraction with posterior chamber intraocular lens (IOL) implantation was performed. After retrobulbar anesthesia was administered, the nystagmus ceased temporarily. Postoperatively, visual acuity in the left eye improved to 20/200. We believe IOL implantation is useful in the treatment of cataracts in albino patients.
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PMID:Posterior chamber intraocular lens implantation in a patient with oculocutaneous albinism. 140 62

Oculocutaneous albinism is defined by the presence of cutaneous and ocular hypopigmentation, the latter associated with nystagmus, iris transillumination, reduced retinal pigment, foveal hypoplasia, and misrouting of the optic fibers at the chiasm. The visual acuity is variable but almost always reduced. We report on two brothers with oculocutaneous albinism and markedly different visual acuity. One brother has a visual acuity of 20/100, while the second has similar cutaneous pigmentation and visual acuity of 20/20 and had not previously been recognized as having oculocutaneous albinism. Both brothers have foveal hypoplasia and misrouting of the optic fibers at the chiasm. Biochemical analysis suggests that this is a tyrosinase-related type of oculocutaneous albinism. This study demonstrates that careful observation of foveal development in relatives with normal vision is necessary to detect all individuals with albinism in a family. A suspected diagnosis of albinism may be confirmed when the visual-evoked potentials show excessive decussation of the optic fibers at the chiasm.
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PMID:Variable expression of vision in sibs with albinism. 195 38

The clinical, ophthalmological, and biochemical characteristics of a 28-year-old black woman with brown oculocutaneous albinism were determined. Hair color was medium brown and skin color was light brown, and a faint tan developed with sun exposure. The irides were light brown in the central one-third, blue-gray in the peripheral two-thirds, and showed punctate and radial translucency. Visual acuity was 20/60 in the right eye and 20/100 in the left eye. There was a moderate pendular nystagmus, and previous surgeries had corrected an exotropia. The foveal reflex was muted, and the retinal pigment was reduced. Hairbulb tyrosinase activity was 1.75 pmoles/120 min/hairbulb, hairbulb glutathione content 0.83 nmoles/hairbulb, and urine excretion of 5-S-cysteinyldopa 174.9 ng/mg creatinine. Electron microscopy of hairbulb and skin melanocytes showed arrested melanosomal development. These findings suggest that there is a partial block in the distal eumelanin pathway in this form of albinism. The ophthalmological characteristics of six additional cases of this form of albinism are also presented.
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PMID:Brown oculocutaneous albinism. Clinical, ophthalmological, and biochemical characterization. 393 94

Seventy-nine Nigerian oculocutaneous albinos were investigated. Fifty-six had typical tyrosinase-positive albinism (TPA) and 23 had brown albinism (BA), a new oculocutaneous type. The TPA were characterized by localized but no generalized skin pigment, yellow hair, blue to brown irides, nystagmus, and reduced or absent retinal pigment. Localized skin pigment included freckles and lentigines. The iris and skin pigment were the result of the slow accumulation of pigment with age as both were found in older individuals. The most severe skin changes were premalignant keratoses and squamous cell carcinoma of the skin, and the skin malignancies were the major factor in limiting the lifespan for TPA. The BA were characterized by generalized light brown skin pigment, light brown hair, blue to brown irides, nystagmus, and reduced retinal pigment. There was little accumulation or change of pigment in the eyes or skin with age. The generalized light skin pigment was effective in reducing sensitivity to solar radiation and very few BA had premalignant keratoses. Pedigree analysis for BA suggested on autosomal recessive inheritance pattern.
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PMID:Albinism in Nigeria with delineation of new recessive oculocutaneous type. 676 77

Nine patients with Prader-Willi syndrome (five female and four male; one Oriental and eight white), all of whom had interstitial deletions of the proximal long arm of one chromosome 15 (q11-q13) were found to have decreased tyrosinase activity in isolated hair bulbs. As infants, all patients had light hair and skin coloring, both of which darkened with age. Light and electron microscopic analysis of skin and hair bulbs disclosed a reduced number of melanocytes in the basal epidermis and hair bulbs. Each patient demonstrated decreased pigmentation of the iris stroma, which was accentuated peripherally and manifested clinically as iris translucency. There was no foveal hypoplasia, nystagmus, or photophobia, and ocular function was normal. Oculocutaneous albinoidism is thus a component of del(15q) Prader-Willi syndrome with reduction of melanocytes of neural crest origin (skin, hair, and iris stroma) and retention of normal retinal and iris pigment epithelia of neuroectodermal origin.
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PMID:Oculocutaneous albinoidism as a manifestation of reduced neural crest derivatives in the Prader-Willi syndrome. 681 26

Oculocutaneous albinism comprises hereditary disorders in which there is a congenital absence or reduction of melanin in the skin, hair and eyes, coupled with nystagmus, photophobia and reduced visual acuity. The body is unable to make melanin (a compound derived from the metabolism of tyrosine) due to the functional absence of the enzyme tyrosinase. The disease is transmitted as an autosomal recessive character. In man, there are six conditions distinguishable in relation to their frequency, and their clinical, biochemical, ultrastructural, and genetic characteristics. The attempt to identify the heterozygote has led to contradictory results. Abnormal transparency of the iris has only been observed in some heterozygotes, and this feature cannot be used to recognise carriers. As far as treatment is concerned, the two main problems are sensitivity to sunlight, with concomitant susceptibility to skin tumors, and collateral vision disturbances. Subjects should avoid direct sunlight. Photophobia can be reduced by wearing sunglasses.
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PMID:[Oculo-cutaneous albinism in man. Biochemical, genetic, clinical, and population aspects]. 688 87

An apparently recessively inherited albinism variant characterized by skin tanning, light but not white hair, uniformly pigmented irides varying in colour from hazel to dark brown, slight nystagmus, divergent strabismus, mild hyperkeratosis and only slight or absent photophobia, occurs among the Elema-speaking peoples of the Gulf Province of Papua New Guinea at frequencies indicating that the gene which produces it is polymorphic. It is readily distinguishable from both classical types of albinism, from the "redskin" variant also found in Papua New Guinea, and from the "yellow mutant" albinism of North America. The differences from the African types of "albinoidism" or "partial albinism" are less marked, and it may represent a similar mutation with simply a different distribution of the melanosomes in the two peoples, Allelism, or lack of it, with classical tyrosinase-positive albinism has not been determined.
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PMID:A high-frequency albinism variant on the gulf coast of Papua. 694 71

Autosomal recessive ocular albinism (AROA) is a disorder characterized by reduced pigmentation of the retina and iris, hypoplastic fovea, variably reduced visual acuity and nystagmus. Pigmentation of the skin and hair is normal, but is usually slightly lighter than in unaffected sibs. We analysed 12 unrelated patients with AROA, and found that two had abnormalities of the tyrosinase (TYR) gene. These two patients were each a compound heterozygote for a different pathologic mutant allele and an allele containing a 'normal' polymorphism, Arg402Gln, which results in a tyrosinase polypeptide with reduced thermal stability. In these patients, AROA thus appears to represent a clinically mild form of OCA1, with a fixed visual deficit resulting from low tyrosinase activity during fetal development but with normal pigmentation of the skin and hair postnatally.
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PMID:Autosomal recessive ocular albinism associated with a functionally significant tyrosinase gene polymorphism. 770 33

The involuntary nystagmus movements of 16-year-old monozygotic twins with tyrosinase negative oculocutaneous albinism were examined. On primary gaze both girls exhibited bilateral conjugate horizontal nystagmus, a jerk with extended foveation waveform, and similar frequencies (2.0 Hz:1.9 Hz), although the fast phases were in opposite directions. The mean amplitudes differed markedly (6.8 degrees:3.7 degrees), as did the position of the null zones (+20 degrees to +30 degrees:-25 degrees to -35 degrees) and the widths of the neutral zones (-25 degrees to +20 degrees:-25 degrees to -35 degrees). Since the twins have identical genotypes these differences must have arisen from other sources.
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PMID:Ocular motor behaviour of monozygotic twins with tyrosinase negative oculocutaneous albinism. 802 67


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