1/12. Bilateral abortive cryptophthalmos associated with oculocutaneous albinism.PURPOSE: To document a case of bilateral abortive cryptophthalmos associated with oculocutaneous albinism. methods: We describe a 13-year-old female patient with blond skin and hair who had anomalous face and eyes first noted at birth. RESULTS: The patient had fair hair and complexion, bilateral anomalous wedge of scalp hair, upper eyebrow and eyelid deformities, cup-shaped ears, broad based nose with depressed bridge and midline groove, iris transillumination and diffuse hypopigmentation and foveal hypoplasia in fundus examination. CONCLUSION: Based on the clinical and laboratory findings, the reported case represents tyrosinase-positive oculocutaneous albinism together with bilateral abortive cryptophthalmos. The oculocutaneous albinism can either be an entirely new criterion to the whole syndrome of cryptophthalmos, or, more probably, the condition can be due to a double affliction which is primarily related with consanguinity of the parents. The importance of ante-natal diagnosis and genetic counseling are emphasized in such cases where the two recessive genes for two different conditions coexist.- - - - - - - - - - ranking = 1keywords = hypopigmentation (Clic here for more details about this article) |
2/12. A splicing mutation of the tyrosinase gene causes yellow oculocutaneous albinism in a Japanese patient with a pigmented phenotype.BACKGROUND: Yellow oculocutaneous albinism (OCA) that is caused by tyrosinase gene mutations shows two characteristics: extreme hypopigmentation at birth and the eventual development of yellow or blond hair. OBJECTIVE: We studied a Japanese girl who had brown hair, a lighter skin color than her unaffected family and brown eyes at 9 months of age. methods: We performed direct sequencing analyses of the tyrosinase gene in her genomic dna. RESULTS: The patient was a compound heterozygote for the DeltaC310 mutation (known to result in absent melanogenic activity) and a second t-->a transition at the 3' end of intron 2. CONCLUSION: The t-->a transition has previously been reported as a splicing mutation in other Caucasian patients with a typical yellow OCA phenotype. However, this patient showed much more pigmentation than that reported in Caucasians. Therefore, we estimate that the mild phenotype results from her genetic pigment background.- - - - - - - - - - ranking = 1keywords = hypopigmentation (Clic here for more details about this article) |
3/12. angelman syndrome associated with oculocutaneous albinism due to an intragenic deletion of the P gene.angelman syndrome (AS) is a neurodevelopmental disorder characterized by mental retardation, speech impairment, ataxia, and happy disposition with frequent smiling. AS results from the loss of expression of a maternal imprinted gene, UBE3A, mapped within 15q11-q13 region, due to different mechanisms: maternal deletion, paternal UPD, imprinting center mutation, and UBE3A mutation. Deletion AS patients may exhibit hypopigmentation of skin, eye, and hair correlating with deletion of P gene localized in the distal part of Prader-Willi (PWS)/AS region. Our patient presented developmental delay, severe mental retardation, absence of speech, outbursts of laughter, microcephaly, ataxia, hyperactivity, seizures, white skin, no retinal pigmentation, and gold yellow hair. His parents were of African ancestry. The SNURF-SNRPN methylation analysis confirmed AS diagnosis and microsatellite studies disclosed deletion with breakpoints in BP2 and BP3. All of the 25 exons and flanking introns of the P gene of the patient, his father, and mother were investigated. The patient is hemizygous for the deleted exon 7 of the P gene derived from his father who is a carrier of the deleted allele. Our patient manifests OCA2 associated with AS due to the loss of the maternal chromosome 15 with the normal P allele, and the paternal deletion in the P gene. As various degrees of hypopigmentation are associated with PWS and AS patients, the study of the P gene in a hemizygous state could contribute to the understanding of its effect on human pigmentation during development and to disclose the presence of modifier pigmentation gene(s) in the PWS/AS region.- - - - - - - - - - ranking = 2keywords = hypopigmentation (Clic here for more details about this article) |
4/12. Oculocutaneous albinism: variable expressivity of nystagmus in a sibship.Traditionally, the diagnosis of ocular or oculocutaneous albinism (OCA) is based on a constellation of features including the presence of nystagmus associated with iris transillumination defects, hypopigmentation of the fundus, and hypoplasia of the fovea and optic nerve head. Nystagmus is the most frequent ocular sign for the ascertainment of albinism particularly in individuals who have lightly-pigmented parents. We report two siblings, a male and female, with minimal, if any, pigmentation of skin and hair, iris transillumination defects, blond fundi, and hypoplasia of the foveae and optic nerve heads who were discordant for nystagmus; the diagnosis of OCA was based on the clinical findings. These siblings presumably have the same genetic hypopigmentation defect and demonstrate that nystagmus is not a consistent finding in OCA and may not be an absolute criterion for diagnosis.- - - - - - - - - - ranking = 2keywords = hypopigmentation (Clic here for more details about this article) |
5/12. Oculocerebral syndrome with hypopigmentation (Cross syndrome): the mixed pattern of hair pigmentation as an important diagnostic sign.The present report describes two female siblings of mixed ancestry (Cape Coloured) with consanguineous parents as further examples of Cross oculocerebral hypopigmentation syndrome. The mixed pattern of hair pigmentation as an important diagnostic sign is emphasized.- - - - - - - - - - ranking = 5keywords = hypopigmentation (Clic here for more details about this article) |
6/12. Low vision rehabilitation of the albino patient.From the eye care professional's point of view, the three most common types of albinism are tyrosinase-negative oculocutaneous albinism, tyrosinase-positive oculocutaneous albinism and ocular albinism. skin and uveal hypopigmentation is variable in this condition depending on the type of albinism. However, all types of albinism lack the necessary uveal pigmentation have subnormal visual acuity. Using low vision rehabilitation techniques such as modifying lighting and providing telescopic optical devices, these patients can experience dramatic improvements in functional visual acuity. This manuscript examines strategic approaches to visual rehabilitation as well as provides a clinical review of the condition.- - - - - - - - - - ranking = 1keywords = hypopigmentation (Clic here for more details about this article) |
7/12. Oculocerebral hypopigmentation syndrome (Cross syndrome).A typical case of Cross syndrome with hypopigmentation, mental and psychomotor retardation, spasticity, bilateral optic atrophy and dental defects in a three-year-old boy is presented. The clinical features of this rare syndrome are discussed.- - - - - - - - - - ranking = 5keywords = hypopigmentation (Clic here for more details about this article) |
8/12. A tyrosinase gene missense mutation in temperature-sensitive type I oculocutaneous albinism. A human homologue to the Siamese cat and the Himalayan mouse.Type I oculocutaneous albinism (OCA) is an autosomal recessive disorder in which deficient synthesis of melanin pigment results from abnormal activity of melanocyte tyrosinase. A novel type I OCA phenotype in which hypopigmentation is related to local body temperature is associated with a missense substitution in tyrosinase, codon 422 CGG (Arg) CAG (Gln). This substitution results in a tyrosinase polypeptide that is temperature-sensitive. This form of type I OCA thus is homologous to the temperature-related forms of albinism seen in the Siamese cat and the Himalayan mouse.- - - - - - - - - - ranking = 1keywords = hypopigmentation (Clic here for more details about this article) |
9/12. Variable expression of vision in sibs with albinism.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.- - - - - - - - - - ranking = 1keywords = hypopigmentation (Clic here for more details about this article) |
10/12. Oculocerebral hypopigmentation syndrome associated with bartter syndrome.We describe a 20-year-old man with tyrosinase-negative oculocutaneous albinism, mental retardation, epilepsy, sensorineural deafness, ataxia, and bartter syndrome. When combined, these neurocutaneous and renal findings form a previously unreported combination. The neurological and cutaneous manifestations of this case are distinctly different from those of the syndrome first reported by Cross et al. [1967]. The literature is reviewed and an attempt is made at classifying the oculocerebral hypopigmentation syndromes.- - - - - - - - - - ranking = 5keywords = hypopigmentation (Clic here for more details about this article) |
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