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PubMed1986

Abnormalities of the central visual pathways in Prader-Willi syndrome associated with hypopigmentation.

Patients with oculocutaneous or ocular albinism have misrouting of optic fibers, with fibers from 20 degrees or more of the temporal retina crossing at the chiasm instead of projecting to the ipsilateral hemisphere. Misrouting can result in strabismus and nystagmus. Because patients with the Prader-Willi syndrome may also have hypopigmentation and strabismus, we wondered whether they too might have misrouting of optic fibers. We therefore studied six patients with Prader-Willi syndrome selected for a history of strabismus, using pattern-onset visually evoked potentials with binocular and monocular stimulation to look for evidence of misrouted retinal-ganglion fibers. Four had hypopigmentation, and three of these four had abnormal evoked potentials indistinguishable from those recorded in human albinos. The two with normal pigmentation had normal responses. These findings indicate that patients with Prader-Willi syndrome who have hypopigmentation have a brain abnormality characterized by misrouting of retinal-ganglion fibers at the optic chiasm--a finding previously reported only in forms of albinism.

Adult↗
PubMed1988

Oculocerebral syndrome with hypopigmentation (Cross syndrome). Report of two siblings born to consanguineous parents.

In this report we describe two siblings, a 17-year-old male and his deceased sister, born to consanguineous parents, and presenting an oculocerebral syndrome with hypopigmentation as first delineated by Cross in 1967. In addition to the cutaneous hypopigmentation, both presented deep mental retardation and spastic tetraplegia with athetoid movements. A remarkable finding in this family is that a third sibling, an otherwise normal 23-year-old male, presents the same hypopigmentation with white-grey hair colour as his two severely affected siblings.

Adolescent↗
PubMed1989

Hypopigmentation: a common feature of Prader-Labhart-Willi syndrome.

In order to determine the frequency and characterization of hypopigmentation in Prader-Labhart-Willi syndrome (PLWS), clinical, cytogenetic and biochemical findings are reported in 56 PLWS individuals. Forty-eight percent of the individuals with PLWS met the criteria for hypopigmentation. Hypopigmentation in PLWS individuals appears to be as common as previously recognized features such as behavioral problems and dental abnormalities. Significant differences in hair color, sun sensitivity, and complexion were found between those PLWS patients with the chromosome 15 deletion and those with normal chromosomes. Individuals with the deletion frequently had lighter hair color, more sun sensitivity, and fairer complexion than did either other family members or nondeletion PLWS patients. No significant differences in biochemical findings (phenylalanine, tyrosine, catecholamines, or beta-melanocyte-stimulating hormone) were found between deletion and nondeletion PLWS patients or between hypopigmented and normally pigmented patients. The data suggest that a gene(s) controlling the activity of tyrosinase or other enzymes required for melanin production is located on proximal 15q.

Adolescent↗
PubMed1996

Analysis of 54 cases of hypopigmentation and hyperpigmentation along the lines of Blaschko.

OBJECTIVE: To define the spectrum of disease in cases of hypopigmentation and hyperpigmentation along the lines of Blaschko more accurately. Pigmentary anomalies along the lines of Blaschko, including hypomelanosis of Ito, linear and whorled nevoid hypermelanosis, and nevus depigmentosus, can be associated with notable abnormal systemic features. We believe that the incidence of associated abnormal features described in previous studies is exaggerated owing to referral and reporting bias. DESIGN: Retrospective review of case series. SETTING: An ambulatory, university hospital, pediatric dermatology practice and a large, city hospital, pediatric dermatology clinic. PATIENTS: Fifty-four children referred consecutively over a 5-year period for evaluation of segmental, linear, or swirled hypopigmentation and/or hyperpigmentation along the lines of Blaschko. MAIN OUTCOME MEASURE: Incidence of associated abnormal systemic features. RESULTS: Extracutaneous abnormal features were present in 16 (30%) of 54 children with aberrant pigmentation along the lines of Blaschko: in 9 (33%) of 27 with hypomelanosis of Ito, in 4 (31%) of 13 with linear and whorled nevoid hypermelanosis, in 1 (11%) of 9 with nevus depigmentosus, and in 2 (40%) of 5 with coexistent hypopigmentation and hyperpigmentation. CONCLUSIONS: Pigmentary anomalies along the lines of Blaschko are associated with abnormal systemic features far less often than has been reported previously. These pigmentary anomalies should not be considered distinct syndromes but rather grouped as a heterogeneous collection of disorders indicative of underlying genetic mosaicism. Such a classification will allow better understanding and evaluation of affected persons.

Adolescent↗
PubMed1993

Hypopigmentation in Angelman syndrome.

Chromosome region 15q is thought to contain one or more genes that are important for melanin pigment synthesis in the hair, skin, and eyes. Hypopigmentation has been identified in the Prader-Willi (PWS) and Angelman (AS) syndromes. We have examined 6 individuals with AS to further characterize the pigment pattern in this condition. The age of the 5 girls and one boy ranged from 2.4 to 7.0 years. None had obvious albinism. Hair color ranged from light blond to brown. Skin was type I in 3 and type II in 3. Eye changes included nystagmus in 2, strabismus in 4, and reduced retinal pigment in 5. The mean hairbulb tyrosinase activity was 0.37 +/- 0.44 pmol/hb/120 min for the individuals with AS, with a range of 0.00 to 1.13 (normal brown control 1.49 +/- 0.79, normal blond control 1.50 +/- 0.85). Electron microscopic examination of hairbulb melanocytes showed normal melanosome and melanocyte architecture and number, but reduced melanin formation, with many stage II and III premelanosomes but few stage IV fully melanized melanosomes. Hypopigmentation characterized by light skin, reduced retinal pigment, low hairbulb tyrosinase activity, and incomplete melanization of melanosomes is part of the phenotype of AS, and is similar to that found in PWS.

Angelman Syndrome↗
PubMedDate not supplied

Linear hypopigmentation after triamcinolone injection: a rare complication of a common procedure.

The development of linear hypopigmentation after intralesional or intraarticular injection of triamcinolone acetonide has been reported in the literature as a very rare side effect. This case report describes a patient with linear hypopigmentation and discusses the possible pathophysiology. Clinicians involved in the care of hypertrophic scars and keloids need to be aware of this rare side effect so that they can guide their patients appropriately. They need to understand the pathogenesis of this complication better so that it may become avoidable.

Anti-Inflammatory Agents↗
PubMed1993

Hypopigmentation, anomalous cerebral dominance and seasonality.

This paper proposes a prenatal seasonal hypopigmentation influence associated with anomalous cerebral dominance that occurs during the winter or early spring. A possible mechanism would be seasonal changes in sex hormone levels that affect the activation and inactivation of DNA by reversible methylation. The proposed prenatal seasonal hypopigmentation effect might be relevant to dyslexia, Prader-Willi syndrome, breast cancer, Alzheimer's and Parkinson's disease. Putative chromosomal loci associated with the proposed seasonal mechanism would be 15q11-13 (dyslexia and Prader-Willi syndrome), 21q region (breast cancer and Alzheimer's disease) and 19p region (pigmentation gene).

Alzheimer Disease↗
PubMed1999

A molecular analysis of the yemenite deaf-blind hypopigmentation syndrome: SOX10 dysfunction causes different neurocristopathies.

The Yemenite deaf-blind hypopigmentation syndrome was first observed in a Yemenite sister and brother showing cutaneous hypopigmented and hyperpigmented spots and patches, microcornea, coloboma and severe hearing loss. A second case, observed in a girl with similar skin symptoms and hearing loss but without microcornea or coloboma, was reported as a mild form of this syndrome. Here we show that a SOX10 missense mutation is responsible for the mild form, resulting in a loss of DNA binding of this transcription factor. In contrast, no SOX10 alteration could be found in the other, severe case of the Yemenite deaf-blind hypopigmentation syndrome. Based on genetic, clinical, molecular and functional data, we suggest that these two cases represent two different syndromes. Moreover, as mutations of the SOX10 transcription factor were previously described in Waardenburg-Hirschsprung disease, these results show that SOX10 mutations cause various types of neurocristopathy.

Amino Acid Sequence↗
PubMed2006

A case of skin hypopigmentation secondary to a corticosteroid injection.

A 47-year-old African-American male presented complaining of Achilles tendon pain. The patient was treated for three weeks with a nonsteroidal anti-inflammatory agent with minimal pain relief. The tendon was subsequently injected with triamcinolone acetonide and five months later, the patient presented with an area of hypopigmentation around the injection site. The patient was diagnosed with hypopigmentation secondary to the steroid injection.

Achilles Tendon↗
PubMed1995

Adolescence mycosis fungoides: an unusual presentation with hypopigmentation.

Mycosis fungoides (M.F.) is a rare cutaneous malignancy of childhood and adolescence. The disease commonly presents with the classic sequence of erythematous patches and plaques. Hypopigmentation as the presenting symptom is distinctly rare. This is the 9th case report of M.F. presenting with hypopigmentation in a patient under 20 years of age. The disease was only partially controlled with PUVA therapy, necessitating nitrogen mustard treatment.

Adolescent↗
PubMed1994

The mouse pink-eyed dilution gene: association with hypopigmentation in Prader-Willi and Angelman syndromes and with human OCA2.

Mutations at the mouse pink-eyed dilution locus, p, cause hypopigmentation. We have cloned the mouse p gene cDNA and the cDNA of its human counterpart, P. The region of mouse chromosome 7 containing the p locus is syntenic with human chromosome 15q11-q13, a region associated with Prader-Willi syndrome (PWS) and Angelman syndrome (AS), both of which involve profound imprinting effects. PWS patients lack sequences of paternal origin from 15q, whereas AS patients lack a maternal copy of an essential region from 15q. However, the critical regions for these syndromes are much smaller than the chromosomal region commonly deleted that often includes the P gene. Hypopigmentation in PWS and AS patients is correlated with deletions of one copy of the human P gene that is highly homologous with its mouse counterpart. A subset of PWS and AS patients also have OCA2. These patients lack one copy of the P gene in the context of a PWS or AS deletion, with a mutation in the remaining chromosomal homologue of the P gene. Mutations in both homologues of the P gene of OCA2 patients who do not have PWS or AS have also been detected.

Albinism, Oculocutaneous↗
PubMed2003

Griscelli syndrome restricted to hypopigmentation results from a melanophilin defect (GS3) or a MYO5A F-exon deletion (GS1).

Griscelli syndrome (GS) is a rare autosomal recessive disorder that associates hypopigmentation, characterized by a silver-gray sheen of the hair and the presence of large clusters of pigment in the hair shaft, and the occurrence of either a primary neurological impairment or a severe immune disorder. Two different genetic forms, GS1 and GS2, respectively, account for the mutually exclusive neurological and immunological phenotypes. Mutations in the gene encoding the molecular motor protein Myosin Va (MyoVa) cause GS1 and the dilute mutant in mice, whereas mutations in the gene encoding the small GTPase Rab27a are responsible for GS2 and the ashen mouse model. We herein present genetic and functional evidence that a third form of GS (GS3), whose expression is restricted to the characteristic hypopigmentation of GS, results from mutation in the gene that encodes melanophilin (Mlph), the ortholog of the gene mutated in leaden mice. We also show that an identical phenotype can result from the deletion of the MYO5A F-exon, an exon with a tissue-restricted expression pattern. This spectrum of GS conditions pinpoints the distinct molecular pathways used by melanocytes, neurons, and immune cells in secretory granule exocytosis, which in part remain to be unraveled.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Reversal of hypopigmentation in phenylketonuria mice by adenovirus-mediated gene transfer.

Phenylketonuria (PKU) is caused by deficiency of phenylalanine hydroxylase (PAH) in the liver. Patients with PKU show increased L-phenylalanine in blood, which leads to mental retardation and hypopigmentation of skin and hair. As a step toward gene therapy for PKU, we constructed a replication-defective, E1/E3-deleted recombinant adenovirus harboring human PAH cDNA under the control of a potent CAG promoter. When a solution containing 1.2 x 10(9) plaque-forming units of the recombinant adenovirus was infused into tail veins of PKU model mice (Pah(enu2)), predominant expression of PAH activity was observed in the liver. The gene transfer normalized the serum phenylalanine level within 24 h. However, it also provoked a profound host immune response against the recombinant virus; as a consequence, the biochemical changes lasted for only 10 d and rechallenge with the virus failed to reduce the serum phenylalanine concentration. Administration of an immunosuppressant, FK506, to mice successfully blocked the host immune response, prolonged the duration of gene expression to more than 35 d, and allowed repeated gene delivery. We noted a change in coat pigmentation from grayish to black after gene delivery. The current study is the first to demonstrate the reversal of hypopigmentation, one of the major clinical phenotypes of PKU in mice as well as in humans, by adenovirus-mediated gene transfer, suggesting the feasibility of gene therapy for PKU.

Adenoviridae↗
PubMed1999

Congenital poikiloderma with unusual hypopigmentation and acral blistering at birth.

Congenital poikiloderma is an uncommon hereditary disorder. It has been reported in association with various syndrome. No case has previously been reported from this environment. We report a case of congenital poikiloderma in a two and a half year old female Nigerian associated with unusual generalised hypopigmentation and acral blisters at birth. The child subsequently developed macular hyperpigmentation on an erythematous background and atrophy of the skin. Although she had some features which were suggestive of Rothmund-Thomson syndrome (RTS), the presence of hypopigmentation at birth, along with acral blistering, was noted to be peculiar to this child. We, therefore, feel that this case presents a distinct variant of congenital poikiloderma that has not been described previously.

Blister↗
PubMed1999

Linear lymphatic hypopigmentation after intralesional corticosteroid injection: report of two cases.

Perilesional and linear hypopigmentation, extending cephalad along the lymphatics, occurred in one patient following intralesional injection of corticosteroid suspension for treatment of a hypertrophic scar, and in a second patient following sub-lesional injection of a soft toe-web corn. Atrophy did not occur. Repigmentation in both patients was complete without specific treatment. Review of the literature and evaluation of these patients suggest that the linear hypopigmentation in these two cases was caused by lymphogenous uptake of the corticosteroid crystals.

Adult↗
PubMed1995

Tyrosinase inhibition due to interaction of homocyst(e)ine with copper: the mechanism for reversible hypopigmentation in homocystinuria due to cystathionine beta-synthase deficiency.

Deficiency of cystathionine beta-synthase (CBS) is a genetic disorder of transsulfuration resulting in elevated plasma homocyst(e)ine and methionine and decreased cysteine. Affected patients have multisystem involvement, which may include light skin and hair. Reversible hypopigmentation in treated homocystinuric patients has been infrequently reported, and the mechanism is undefined. Two CBS-deficient homocystinuric patients manifested darkening of their hypopigmented hair following treatment that decreased plasma homocyst(e)ine. We hypothesized that homocyst(e)ine inhibits tyrosinase, the major pigment enzyme. The activity of tyrosinase extracted from pigmented human melanoma cells (MNT-1) that were grown in the presence of homocysteine was reduced in comparison to that extracted from cells grown without homocysteine. Copper sulfate restored homocyst(e)ine-inhibited tyrosinase activity when added to the culture cell media at a proportion of 1.25 mol of copper sulfate per 1 mol of DL-homocysteine. Holo-tyrosinase activity was inhibited by adding DL-homocysteine to the assay reaction mixture, and the addition of copper sulfate to the reaction mixture prevented this inhibition. Other tested compounds, L-cystine and betaine did not affect tyrosinase activity. Our data suggest that reversible hypopigmentation in homocystinuria is the result of tyrosinase inhibition by homocyst(e)ine and that the probable mechanism of this inhibition is the interaction of homocyst(e)ine with copper at the active site of tyrosinase.

Adolescent↗
PubMed1991

Disorders of hypopigmentation in children.

The most common disorders of hypopigmentation in children are pityriasis alba, vitiligo, nevus depigmentosus, and tinea versicolor. Pityriasis alba usually presents as ill defined, scaly patches of hypomelanosis on the cheeks of children with an atopic diathesis. The face is also a favored site for vitiligo, but the distribution is periorificial, and the pigment loss is complete because of a destruction of melanocytes. Vitiligo is an acquired, progressive disorder in contrast to nevus depigmentosus, which is a stable, congenital leukoderma. The localized form of nevus depigmentosus must be distinguished from an ash leaf spot, the earliest cutaneous manifestation of tuberous sclerosis, whereas the systematized form may be confused with hypomelanosis of Ito, another neurocutaneous disorder. The lesions of tinea versicolor favor the upper trunk of adolescents, and potassium hydroxide examination of the associated scale reveals hyphal and yeast forms of P. orbiculare. Any inflammatory process in the skin such as dermatitis or psoriasis can resolve with areas of hypopigmentation.

Adolescent↗