Pigmentary disorders of the eyes and skin

Scleral Discoloration Because of Minocycline Use: A Case Report and Review of the Literature

In this case report, we highlight minocycline-induced scleral hyperpigmentation, combined with ear and fingernail discoloration that developed after over 15 years of use for rosacea in a 78-year-old male with multiple medical comorbidities. Minocycline, a tetracycline antibiotic, is used to treat rosacea and acne as well as some orthopedic infections. It is typically used for extended periods of time; long-term use of minocycline is associated with hyperpigmentation of the sclera, conjunctiva, retina, teeth, skin, subcutaneous fat, oral mucosa, tympanic membrane, and gingiva. This case highlights that hyperpigmentation is more likely to occur in older patients than in younger patients. Scleral hyperpigmentation is not associated with vision loss; however, cosmetic concerns can prompt discontinuation of minocycline. Nonetheless, after cessation, the lesions persist in some patients. Monitoring for hyperpigmentation in patients using minocycline is important, as the hyperpigmentation is more likely to be permanent with long-term use.

Waardenburg syndrome-associated neurotrophic keratopathy in a child treated with neurotization surgery

Waardenburg syndrome (WS) is a congenital developmental disorder characterized by congenital sensorineural hearing loss and pigmentary deficiencies in the iris, hair, and skin. Ocular associations of WS include choroidal and iris hypopigmentation and foveal hypoplasia. Possible associations include cataracts and retinal vein occlusion. We report the first case of neurotrophic cornea and relate our experience with neurotization surgery.

Neurological Waardenburg-Shah syndrome: a diagnostic challenge in a child with skin hypopigmentation and neurological manifestation

Peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, Waardenburg syndrome and Hirschsprung disease (PCWH) is a rare manifestation of Waardenburg-Shah syndrome associated with mutations in the SOX10 gene. The phenotypic expression is variable, thus presenting a diagnostic challenge. Clinical manifestations of PCWH may mimic other neurocutaneous syndromes. A thorough history, careful physical examination, appropriate imaging studies and an index of suspicion are needed to diagnose this condition. We describe an adolescent girl with skin hypopigmentation and blue irides associated with sensorineural hearing loss, Hirschsprung disease, as well as seizures with neurological signs, and discuss the challenges in diagnosing PCWH.

The spectrum of melanocytic nevi and their clinical implications

The magnitude of the topic of melanocytic nevi (MN) is directly related to its relevance in everyday clinical work. The different MN have different prognostic significance in regard to comorbidity and possible risk of transformation. In addition to the criteria of the ABCDE rule, relevant criteria in the assessment of an MN are the time of occurrence, the growth tendency, the distribution and the comparison with other MN of the respective individual.

The present CME article provides an overview of the knowledge that has been gained with regard to the development and genetic background of MN and any risk of degeneration that may exist. In addition, certain clinical and/or dermatoscopic features may provide the clinician with a decision‐making aid in the management of different MNs.

Melanosome Biogenesis in the Pigmentation of Mammalian Skin

Melanins, the main pigments of the skin and hair in mammals, are synthesized within membrane-bound organelles of melanocytes called melanosomes. Melanosome structure and function are determined by a cohort of resident transmembrane proteins, many of which are expressed only in pigment cells and localize specifically to melanosomes. Defects in the genes that encode melanosome-specific proteins or components of the machinery required for their transport in and out of melanosomes underlie various forms of ocular or oculocutaneous albinism, characterized by hypopigmentation of the hair, skin, and eyes and by visual impairment. We review major components of melanosomes, including the enzymes that catalyze steps in melanin synthesis from tyrosine precursors, solute transporters that allow these enzymes to function, and structural proteins that underlie melanosome shape and melanin deposition. We then review the molecular mechanisms by which these components are biosynthetically delivered to newly forming melanosomes-many of which are shared by other cell types that generate cell type-specific lysosome-related organelles. We also highlight unanswered questions that need to be addressed by future investigation.

MITF p.Arg217Thr Variant Identified in a Han Chinese Family with Tietz/Waardenburg Syndrome

Waardenburg syndrome (WS) is a group of rare genetic disorders characterized by hearing loss, changes in coloring of hair, skin, and eyes, and alterations in the shape of the face. Tietz syndrome is another rare disorder which presented similar phenotypes to WS. Patients with Tietz/Waardenburg syndrome often present with pale blue eyes, albino skin, and distinctive hair coloring, such as a patch of white hair or hair that prematurely turns gray. At present, more than six candidate genes are responsible for four types of Waardenburg syndrome and Tietz syndrome. This study is aimed at identifying the pathogenic gene variants in a three-generation Han Chinese family with hearing loss, blue-gray iris, albino skin, and white hair. In order to discover the molecular genetic lesion underlying the disease phenotype, whole exome sequencing in the proband, with Tietz/Waardenburg syndrome phenotypes, of a Han Chinese family from HeBei, China, was conducted. A novel heterozygous c.650G>C/p.Arg217Thr variant in melanocyte inducing transcription factor (MITF) was identified. Sanger sequencing further validated that this mutation existed in three affected individuals and absent in healthy family members. Bioinformatics analysis predicted that this mutation was deleterious. Our study further identified the genetic lesion of the family. Simultaneously, our study may also contribute to genetic counseling, embryonic screening of in vitro fertilized embryos, and prenatal genetic diagnosis of patients with Tietz/Waardenburg syndrome, especially for the proband, unmarried and unpregnant women, to reduce familial transmission in this Han Chinese family.

Dystrophia canthorum in Waardenburg syndrome with a novel MITF mutation

AIM

To reveal a novel MITF gene mutation in Waardenburg syndrome (WS), which is an autosomal dominant inherited neurogenic disorder that consists of various degrees of sensorineural deafness and pigmentary abnormalities in the eyes, hair and skin.

METHODS

The genetic analysis of the Chinese family was conducted by whole-exome sequencing, then the results were confirmed by Sanger sequencing.

RESULTS

WS is classified into type I to IV, which are identified by the W index, clinical characteristics and additional features. The MITF gene mostly accounts for WS type II. In this study, a de novo heterozygous mutation in the MITF gene, c.638A>G in exon 7, was identified in the patient diagnosed with WS type I features, as the W index was 2.17 (over 2.10), with dystrophia canthorum, congenital bilateral profound hearing loss, bilateral heterochromia irides, premature greying of the hair, and excessive freckling on the face at birth. She also underwent refractive errors and esotropia, reduced pigmentation of the choroid and visible choroid vessels. The mutation was not found in previous studies or mutation databases.

CONCLUSION

The novel mutation in the MITF gene, which altered the protein in amino acids 213 from the glutamic acid to glycine, is the genetic pathological cause for WS features in the patient. Those characteristics of this family revealed a novel genetic heterogeneity of MITF in WS, which expanded the database of MITF mutations and offered a possible in correcting the W index value of WS in distinct ethnicities. Moreover, ocular symptoms should be emphasized in all types of WS patients.

Understanding mutational effects in digenic diseases

To further our understanding of the complexity and genetic heterogeneity of rare diseases, it has become essential to shed light on how combinations of variants in different genes are responsible for a disease phenotype. With the appearance of a resource on digenic diseases, it has become possible to evaluate how digenic combinations differ in terms of the phenotypes they produce. All instances in this resource were assigned to two classes of digenic effects, annotated as true digenic and composite classes. Whereas in the true digenic class variants in both genes are required for developing the disease, in the composite class, a variant in one gene is sufficient to produce the phenotype, but an additional variant in a second gene impacts the disease phenotype or alters the age of onset. We show that a combination of variant, gene and higher-level features can differentiate between these two classes with high accuracy. Moreover, we show via the analysis of three digenic disorders that a digenic effect decision profile, extracted from the predictive model, motivates why an instance was assigned to either of the two classes. Together, our results show that digenic disease data generates novel insights, providing a glimpse into the oligogenic realm.

Laser treatment of medical skin disease in women

Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS), notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the body of literature that exists for the laser treatment of women with these medical conditions.

Minocycline-Induced Scleral and Dermal Hyperpigmentation

PURPOSE

To present a case of minocycline-induced blue scleral pigmentation and discuss the pathophysiology and differential diagnoses. The uses, mechanisms, and other adverse effects of minocycline will also be highlighted.

CASE REPORT

An elderly Caucasian male patient presented for routine ocular examination complaining of blue discoloration to the whites of his eyes. He was found to have bilateral blue scleral pigmentation and blue discoloration to various other dermal areas of his body. The blue pigmentation was also visible in the posterior segment within a scleral crescent around his right optic nerve. This pigmentation was determined to be caused by long-term use of oral minocycline.

CONCLUSIONS

Long-term minocycline use may induce scleral, dermal, and organ hyperpigmentation, typically blue or black in coloration. The pigmentation may reverse with discontinuation of the medication, but can also be permanent. The exact mechanism of pigment deposition remains uncertain, but several theories have been proposed. While the cosmetic appearance may be dramatic, this side effect is not known to cause any systemic or ocular morbidity.

Retrospective analysis in oculocutaneous albinism patients for the 2.7 kb deletion in the OCA2 gene revealed a co-segregation of the controversial variant, p.R305W

Background

Oculocutaneous albinism (OCA) is an autosomal recessive disorder. A significant portion of OCA patients has been found with a single pathogenic variant either in the TYR or the OCA2 gene. Diagnostic sequencing of the TYR and OCA2 genes is routinely used for molecular diagnosis of OCA subtypes. To study the possibility that genomic abnormalities with single or multiple exon involvement may account for a portion of the potential missing pathogenic variants (the second), we retrospectively analyzed the TYR gene by long range PCR and analyzed the target 2.7 kb deletion in the OCA2 gene spanning exon 7 in OCA patients with a single pathogenic variant in the target genes.

Results

In the 108 patients analyzed, we found that one patient was heterozygous for the 2.7 kb OCA2 gene deletion and this patient was positive with one pathogenic variant and one possibly pathogenic variant [c.1103C>T (p.Ala368Val) + c.913C>T (p.R305W)]. Further analysis of maternal DNA, and two additional OCA DNA homozygous for the 2.7 kb deletion, revealed that the phenotypically normal mother is heterozygous of the 2.7 kb deletion and homozygous of the p.R305W. The two previously reported patients with homozygous of the 2.7 kb deletion are also homozygous of p.R305W.

Conclusions

Among the reported pathogenic variants, the pathogenicity of the p.R305W has been discussed intensively in literature. Our results indicate that p.R305W is unlikely a pathogenic variant. The possibility of linkage disequilibrium between p.R305W with the 2.7 kb deletion in OCA2 gene is also suggested.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-017-0149-3) contains supplementary material, which is available to authorized users.

Common Pediatric Skin Lesions: A Comprehensive Review of the Current Literature

The timely diagnosis and treatment of dermatologic disease in the pediatric population can be challenging. A basic, yet comprehensive knowledge of common lesions is essential for a successful practice in plastic surgery. In this article, the authors describe vascular, cystic, and pigmented cutaneous lesions that are commonly encountered in the pediatric population. Epidemiology, pathogenesis, clinical course, and management options are discussed for each.

An Orbital Malignant Melanoma Arising in Cellular Blue Nevus in a Patient with Nevus of Ota

Melanomas arising from orbital melanocytic proliferations are exceedingly rare. Many questions remain regarding their development and malignant transformation. We report on a 45-year-old Caucasian woman with a nevus of Ota that presented with visual disturbances involving her right eye and was found to have a biopsy-proven cellular blue nevus in the orbital space. Five years later, she presented with proptosis and worsening symptoms. Biopsy at that time showed a cellular blue nevus with areas of melanoma. We conclude that patients with a nevus of Ota or an orbital cellular blue nevus, particularly Caucasians, should be monitored for ocular/orbital involvement and followed closely for signs of rapid growth. There may be a progressive evolution to melanoma from a blue nevus.  

A Classic Case of Tuberous Sclerosis with Multisystem Involvement Including Giant Bilateral Renal Angiomyolipomas Presenting as Massive Hematuria

Background

Tuberous Sclerosis (TSC) also known as Bourneville disease is a neurocutaneous syndrome having an autosomal dominant inheritance pattern, though the condition has a high rate of spontaneous mutation. It is the second most common neurocutaneous syndrome after neurofibromatosis. This disease demonstrates a widespread potential for hamartomatous growths in multiple organ systems.

Case Report

We report a case of a 36-year-old female with TSC presenting as massive hematuria with underlying giant bilateral renal angiomyolipomas (AML) with estimated total tumor burden of more than 8 kg which is to the best of our knowledge the highest ever reported. The patient also had lymphangioleiomyomatosis and lesions in the brain, skin, teeth and bones.

Conclusions

TSC has a wide variety of clinical and radiologic manifestations. It should be suspected when some of the common radiological manifestations are found, including CNS involvement, renal and hepatic AMLs and LAM, even if clinical signs are not obvious. Renal AMLs in setting of TSC may reach giant proportions and may present with massive hematuria.