Lysosome-related organelles (LROs) are a heterogeneous group of vesicles that share various features with lysosomes, but are distinct in function, morphology, and composition. The biogenesis of LROs employs a common machinery, and genetic defects in this machinery can affect all LROs or only an individual LRO, resulting in a variety of clinical features. In this review, we discuss the main components of LRO biogenesis. We also summarize the function, composition, and resident cell types of the major LROs. Finally, we describe the clinical characteristics of the major human LRO disorders.

/pdf/disorders-of-lysosome-related-organelle-biogenesis-clinical-4jbnmqhziz.pdf

Disorders of lysosome-related organelle biogenesis: clinical and molecular genetics.

Griscelli syndrome (GS) is a rare autosomal recessive disorder caused by mutations in either the myosin VA (GS1), RAB27A (GS2) or melanophilin (GS3) genes The three GS subtypes are commonly characterized by pigment dilution of the skin and hair, due to defects involving melanosome transport in melanocytes Here, we review how detailed studies concerning GS have contributed to a better understanding of the molecular mechanisms involved in vesicle transport and membrane trafficking processes Additionally, we demonstrate that the identification and biological analysis of novel disease-causing mutations highlighted the functional importance of the RAB27A-MLPH-MYO5A tripartite complex in intracellular melanosome transport As the small GTPase Rab27a is able to interact with multiple effectors, including Slp2-a and Myrip, we report on their presumed role in melanosome transport Furthermore, we summarize data suggesting that RAB27B and RAB27A are functionally redundant and hereby provide further insight into the pathogenesis of GS2 Finally, we discuss how the gathered knowledge about the RAB27A-MLPH-MYO5A tripartite complex can be translated into a possible therapeutic application to reduce (hyper)pigmentation of the skin

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1755-148X.2009.00558.x

Griscelli syndrome: a model system to study vesicular trafficking.

9. Tezcan I et al: Successful bone marrow transplantation in a case of Griscelli disease which presented in accelerated phase with neurological involvement. Bone Marrow Transplant 24:931-933, 1999 10. Schuster F et al: Griscelli syndrome: Report of the first peripheral blood stem cell transplant and the role of mutations in the RAB27A gene as an indication for BMT. Bone Marrow Transplant 28:409-412, 2001

http://www.fitzpatricksdermatology.com/references/Fitzpatricks_Derm8e_Ref_Ch075.pdf

Hypomelanoses and hypermelanoses

Beau lines, onychomadesis, and retronychia are nail dystrophies with distinctive clinical findings. Trauma has been reported as the initiating factor in each of these entities. Infections, severe medical illnesses, major surgery/anesthesia, medication side effects, and autoimmune disease can produce Beau lines and onychomadesis. This article illustrates the common underlying pathophysiological mechanism that produces each of these nail dystrophies.

Beau lines, onychomadesis, and retronychia: A unifying hypothesis

Silvery hair is a rare clinical manifestation which is a common presentation in a group of rare syndromes which usually present in the pediatric age group together termed as "silvery hair syndrome," consisting of Chediak-Higashi syndrome (CHS), Griscelli syndrome (GS), and Elejalde disease. CHS is a rare autosomal recessive disorder. It is characterized by mild pigment dilution (partial oculocutaneous albinism), silvery blond hair, severe phagocytic immunodeficiency, bleeding tendencies, recurrent pyogenic infections, progressive sensory or motor neurological defects. GS is also a rare autosomal recessive disorder characterized by reduced skin pigmentation, often regarded as partial albinism and silvery grey hair combined with immunodeficiency. To make correct diagnosis and to differentiate between CHS and GS, it requires light microscopic examination of skin and hair shafts, immunological and peripheral blood smear evaluation. They have been reported to be associated with some common clinical association as a part of the syndrome due to pigmentary delusion, neurological dysfunction, and severe life-threatening infections due to neutrophil phagocytosis dysfunction. There are reports of few rare associations and varied presentations and variable mean survival age. We report two cases with common presentation of silvery hair but varied systemic and clinical manifestations and survival in two cousin brothers from the same family.

Silvery hair syndrome in two cousins: Chediak-Higashi syndrome vs griscelli syndrome, with rare associations

Elejalde syndrome is a rare autosomal recessive condition, with only 10 reported cases through 2001. It is characterized by silvery hair, pigment abnormalities, and profound central nervous system dysfunction. The differential diagnosis includes Griscelli and Chediak-Higashi syndromes, which present with silvery hair, pigment abnormalities, central nervous system alterations, and severe immunologic dysfunction. We report a 6- year-old girl with Elejalde syndrome and review Elejalde, Griscelli, and Chediak-Higashi syndromes.

/pdf/elejalde-syndrome-report-of-a-case-and-review-of-the-1fpevcwcjd.pdf

Elejalde syndrome: report of a case and review of the literature.

Nail involvement in pemphigus vulgaris is rare. We describe 5 patients with pemphigus vulgaris presenting nail involvement. In this disease, nail manifestations present, by order of frequency, as chronic paronychia, onychomadesis, onycholysis, Beau's lines and trachyonychia. All our 5 cases presented with paronychia, and 1 of them also had Beau's lines. Treatment with prednisone and/or cyclophosphamide controlled mucocutaneous and nail manifestations in all cases.

/pdf/nail-manifestations-in-pemphigus-vulgaris-2gdym844vt.pdf

Juliana Burihan Cahali

Papers

Elejalde syndrome: report of a case and review of the literature.

Nail manifestations in pemphigus vulgaris