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)

Oculocutaneous albinism (OCA) is a group of inherited disorders of melanin biosynthesis characterized by a generalized reduction in pigmentation of hair, skin and eyes. The prevalence of all forms of albinism varies considerably worldwide and has been estimated at approximately 1/17,000, suggesting that about 1 in 70 people carry a gene for OCA. The clinical spectrum of OCA ranges, with OCA1A being the most severe type with a complete lack of melanin production throughout life, while the milder forms OCA1B, OCA2, OCA3 and OCA4 show some pigment accumulation over time. Clinical manifestations include various degrees of congenital nystagmus, iris hypopigmentation and translucency, reduced pigmentation of the retinal pigment epithelium, foveal hypoplasia, reduced visual acuity usually (20/60 to 20/400) and refractive errors, color vision impairment and prominent photophobia. Misrouting of the optic nerves is a characteristic finding, resulting in strabismus and reduced stereoscopic vision. The degree of skin and hair hypopigmentation varies with the type of OCA. The incidence of skin cancer may be increased. All four types of OCA are inherited as autosomal recessive disorders. At least four genes are responsible for the different types of the disease (TYR, OCA2, TYRP1 and MATP). Diagnosis is based on clinical findings of hypopigmentation of the skin and hair, in addition to the characteristic ocular symptoms. Due to the clinical overlap between the OCA forms, molecular diagnosis is necessary to establish the gene defect and OCA subtype. Molecular genetic testing of TYR and OCA2 is available on a clinical basis, while, at present, analysis of TYRP1 and MATP is on research basis only. Differential diagnosis includes ocular albinism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Griscelli syndrome, and Waardenburg syndrome type II. Carrier detection and prenatal diagnosis are possible when the disease causing mutations have been identified in the family. Glasses (possibly bifocals) and dark glasses or photocromic lenses may offer sufficient help for reduced visual activity and photophobia. Correction of strabismus and nystagmus is necessary and sunscreens are recommended. Regular skin checks for early detection of skin cancer should be offered. Persons with OCA have normal lifespan, development, intelligence and fertility.
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PMID:Oculocutaneous albinism. 1798 20

Patients with OCA are characterized by reduced skin and hair pigmentation and consequent photosensitivity, actinic damage and risk of skin cancer, and by reduced visual acuity and nystagmus. Our survey of Japanese patients revealed that OCA1 was the most frequent type at 34%, while type 2 was present at less than 10%. OCA3 was absent. OCA4, which is a rare type worldwide, was the second most frequent type at 27%. Unexpectedly 10% of the patients turned out to be Hermansky-Pudlak syndrome type 1. Furthermore, the pathogenic p.A481T allele for OCA2, which has 70% melanogenesis activity, was found in approximately 12% of normally pigmented people, indicating that sub-clinical OCA2 might be more frequent in the Japanese than currently thought. And OCA4 is one of the most common types in Japanese patients, despite being rare worldwide.
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PMID:Recent advances in genetic analyses of oculocutaneous albinism types 2 and 4. 1840 68

The term, oculocutaneous albinism (OCA), describes a group of inherited disorders of melanin biosynthesis that exhibits congenital hypopigmentation of ocular and cutaneous tissues. The clinical spectrum of OCA ranges from a complete lack of melanin pigmentation to mildly hypopigmented forms. OCA1A is the most severe type with a complete lack of melanin production throughout life; the milder forms OCA1B, OCA2, OCA3 and OCA4 show some pigment accumulation over time. Clinical manifestations include various degrees of congenital nystagmus, iris hypopigmentation and translucency, reduced pigmentation of the retinal pigment epithelium, foveal hypoplasia, reduced visual acuity and refractive errors, color vision impairment, and prominent photophobia. All four types of OCA are inherited as autosomal recessive disorders. At least four genes are responsible for the different types of the disease (TYR, OCA2, TYRP1, and MATP). Diagnosis is based on clinical findings of hypopigmentation of the skin and hair in addition to the characteristic ocular symptoms. Herein we present a case with OCA1A.
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PMID:Oculocutaneous albinism type 1A: a case report. 1909 51

Oculocutaneous albinism (OCA), which is roughly divided into non-syndromic and syndromic OCA, is a group of autosomal recessive disorders caused by mutations in genes associated with pigmentation. Patients with OCA have hypopigmentation and ocular manifestations such as photophobia, amblyopia, and nystagmus. Hermansky-Pudlak syndrome (HPS), the most common syndromic OCA, is characterized by the additional features of a bleeding tendency and other critical systemic comorbidities such as pulmonary fibrosis and immunodeficiency. NGS-based gene analyses have identified several new causative genes for OCA and have detected rare subtypes of OCA with high accuracy including Japanese patients. In our survey of 190 Japanese OCA patients/families, OCA4 is the most common subtype (25.3%) followed by OCA1 (20.0%), HPS1 (14.7%), and OCA2 (8.4%). Similar to the A481T variant in OCA2, which is associated with a mild form of OCA2 and skin color variation, the c.-492_489delAATG variant located in the promoter region of SLC45A2 has been uniquely identified in Japanese patients with a mild form of OCA4. Further, rare OCA subtypes, including OCA3, HPS2, HPS3, HPS4, HPS5, HPS6, and HPS9, have also been identified in Japanese patients. The clinical characteristics and underlying molecular mechanisms of each subtype of OCA are concisely summarized in this review.
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PMID:Current landscape of Oculocutaneous Albinism in Japan. 3296 95