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The article presents a case study of a 10-year-old boy diagnosed with familial gigantic melanocytosis, characterized by diffuse brown hyperpigmentation and silvery grey hair. It discusses the clinical features, histopathological findings, and differential diagnosis of this rare condition, emphasizing the importance of histopathological examination in accurately diagnosing familial gigantic melanocytosis and differentiating it from similar disorders.

One of the rare but a common symptom of some genetic diseases presenting in Pediatric age group is silvery hair. These disorders termed as "silvery hair syndrome" consist of Griscelli syndrome (GS), Chediak-Higashi syndrome (CHS) and Elejalde disease. Among these syndromes primary immunodeficiency is present only in CHS and GS type II. CHS which is characterized by severe defect in phagocytic function leading to recurrent infections with pyogenic organism, silver blond hair, partial oculocutaneous albinism, progressive motor or sensory neurologic defects and bleeding tendencies is a rare autosomal recessive defect. Griscelli syndrome 2 is also a rare disorder with autosomal recessive inheritance associated with dilution of pigments in skin, hair, splenohepatomegaly, immune and neurological dysfunction and pancytopenia. Because of overlapping clinical presentation, they closely mimic each other. Hence here we are focusing on differentiating these two disorders and highlighting the diagnostic dilemma. We report two cases which were referred to our tertiary care center of central India with varied clinical manifestations and complications, sharing a common feature of silvery hair. [ABSTRACT FROM AUTHOR]

Griscelli syndrome type 2 (GS2) is an autosomal recessive immunodeficiency characterized by hair hypopigmentation, recurrent fever, hepatosplenomegaly and pancytopenia. This study aims to find new genetic changes and clinical features in 18 children with GS2 caused by the RAB27A gene defect. In all, 18 Iranian children with GS2 who presented with silver grey hair and frequent pyogenic infection were included in this study. After recording demographic and clinical data, PCR sequencing of the RAB27A gene was performed for all exons and exon–intron boundaries. Two patients in this study were subjected to whole‐exome sequencing followed by Sanger sequencing. Light microscopy study of hair showed large irregular clumps of pigment with the absence of giant granules on the blood smear. Mutation analysis of the RAB27A gene identified two novel missense mutations as homozygous in a patient, one in exon 2, c.140G>C and another in exon 4, c.328G>T. In addition, for 17 other patients, 6 reported mutations were obtained including c.514_518delCAAGC, c.150_151delAGinsC, c.400_401delAA, c.340delA, c.428T>C and c.221A>G. The mutation c.514_518delCAAGC was the most frequent and found in 10 patients; this mutation may be considered a hotspot in Iran. Early diagnosis and treatment of RAB27A deficiency can contribute to better disease outcomes. In affected families, genetic results could be urgently needed to make a timely decision about haematopoietic stem cell transplantation and prenatal diagnosis. [ABSTRACT FROM AUTHOR]

The article focuses on a study evaluating how physicians differentiate between Chediak–Higashi syndrome (CHS) and Griscelli syndrome (GS) based on facial photographs. Topics include the clinical features of both syndromes, the use of a PowerPoint-based quiz to assess diagnostic accuracy, and the statistical analysis of physicians' ability to distinguish between the two conditions based on facial characteristics such as sunburnt-cheeks sign in CHS versus uniform tanning in GS.

Griscelli syndrome type 1 (GS1) is a rare inherited autosomal recessive disease caused by a deleterious variant in the MYO5A gene and characterized by general hypopigmentation, neurological symptoms, motor disability, hypotonia, and vision abnormality. Only nine pathogenic variants in the MYO5A gene have been confirmed in association with the GS1. All of the reported pathogenic variants are truncating. Herein, two siblings from a consanguineous Iranian family with abnormal pigmentation and neurological symptoms were referred for genetic counseling. Whole-exome sequencing (WES) revealed a novel homozygous truncating variant c.1633_1634delAA (p.Asn545Glnfs*10) in the MYO5A gene, which was completely co-segregated with the phenotype in all affected and unaffected family members. Computational analysis and protein modeling demonstrated the deleterious effects of this variant on the structure and function of the protein. The variant, according to ACMG guidelines, was classified as pathogenic. Besides the novelty of the identified variant, our patients manifested more severe clinical symptoms and presented distal hyperlaxity in all four limbs, which was a new finding. In conclusion, we expanded the mutational and phenotypic spectrum of the GS1. Moreover, by studying clinical manifestations in all molecularly confirmed reported cases, provided a comprehensive overview of clinical presentation, and attempted to find a genotype–phenotype correlation. [ABSTRACT FROM AUTHOR]

Lysosome-related organelles (LROs) are a group of functionally diverse, cell type-specific compartments. LROs include melanosomes, alpha and dense granules, lytic granules, lamellar bodies and other compartments with distinct morphologies and functions allowing specialised and unique functions of their host cells. The formation, maturation and secretion of specific LROs are compromised in a number of hereditary rare multisystem disorders, including Hermansky-Pudlak syndromes, Griscelli syndrome and the Arthrogryposis, Renal dysfunction and Cholestasis syndrome. Each of these disorders impacts the function of several LROs, resulting in a variety of clinical features affecting systems such as immunity, neurophysiology and pigmentation. This has demonstrated the close relationship between LROs and led to the identification of conserved components required for LRO biogenesis and function. Here, we discuss aspects of this conserved machinery among LROs in relation to the heritable multisystem disorders they associate with, and present our current understanding of how dysfunctions in the proteins affected in the disease impact the formation, motility and ultimate secretion of LROs. Moreover, we have analysed the expression of the members of the CHEVI complex affected in Arthrogryposis, Renal dysfunction and Cholestasis syndrome, in different cell types, by collecting single cell RNA expression data from the human protein atlas. We propose a hypothesis describing how transcriptional regulation could constitute a mechanism that regulates the pleiotropic functions of proteins and their interacting partners in different LROs. [ABSTRACT FROM AUTHOR]

Silvery white hair is an infrequent clinical manifestation seen in Chediak Higashi syndrome, Elejalde disease and Griscelli syndrome. Pigmentary dilution is common to all the three conditions. Clinical examination, hair and skin microscopic examination are instrumental in differentiating these syndromes. Presence of silvery hair in a patient should prompt the physician to look for any associated features. Presence of neurologic and immunologic impairment carries a poor prognosis. Here we describe a series of three cases of Griscelli syndrome. [ABSTRACT FROM AUTHOR]

Introduction: Griscelli syndrome (GS) is a very rare autosomal recessive disorder, belongs to group of "silvery hair syndromes" which includes Chediak-Higashi syndrome (CHS) and Elejalde syndrome. Hair light microscopy helps in the differentiation of GS and CHS, as both manifest with clinical features. Trichoscopy is useful in the diagnosis of many hair shaft disorders. Here, authors describe the trichoscopic features of GS in skin of color. Materials and Methods: This was an observational study conducted in a private dermatology clinic and in a tertiary care hospital. A total of 5 cases of suspected GS were referred by pediatrician. Consent was obtained. The demographic data in terms of age, gender, consanguinity, and clinical history was documented. Trichoscopic examination was performed with FotoFinder videodermoscope with 20x magnification, the clinical images were captured with Medicam 1000. Trichoscopy showed large and irregular pigment clumps in 4 cases. One case demonstrated hypopigmentation of hair without pigment clumps [Figure 3a]. Results: Trichoscopy showed large and irregular pigment clumps in 4 cases. One case demonstrated hypopigmentation of hair without pigment clumps. Conclusion: Trichoscopy shows characteristic features GS. It is a useful method when facility for light or polarized microscope is unavailable. [ABSTRACT FROM AUTHOR]

Copyright of Dermatology Review / Przeglad Dermatologiczny is the property of Termedia Publishing House and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Silvery Hair Syndromes (SHS), an autosomal recessive inherited disorder, includes Chediak–Higashi syndrome (CHS), Griscelli syndrome (GS), Hermansky–Pudlak syndrome (HPS), and Elejalde syndrome. Associated immunological and neurological defects and predilection for hemophagocytic lymphohistiocytosis (HLH) makes them a distinctive entity in pediatric practice. Thorough clinical examination, bedside investigations such as peripheral blood smear (PBS) and hair microscopy, and bone marrow (BM) examination are inexpensive and reliable diagnostic tools. Methods: We report 12 cases with SHS (CHS, n = 06; GS, n = 04; HPS, n = 02). Results: 8 out of 12 SHS children (CHS-05, GS-03) presented with HLH. Out of 5 cases of CHS with HLH, 2 died, 3rd is stable post-chemotherapy; 4th completed chemotherapy, underwent matched related hematopoietic stem cell transplant (HSCT), and is stable 8 months off treatment. The 5th child completed chemotherapy and is in process of transplant. One CHS child without HLH is thriving without any treatment. Of the 4 GS cases, 3 presented with HLH and received chemotherapy (HLH 2004 protocol). One lost follow-up after initial remission; another had recurrence 7 months off treatment and discontinued further treatment. The third child had recurrence 1.5 years after initial chemotherapy; HLH 2004 protocol was restarted followed by HSCT from matched sibling donor; is currently well, 2.5 years post-transplant. One child with GS had neurological features with no evidence of HLH and did not take treatment. Of 2 children with HPS, one presented with severe sepsis and the other with neurological problems. They were managed symptomatically. Conclusion: In SHS with HLH, chemotherapy followed by allogeneic hematopoietic stem cell transplantation is a promising curative option. [ABSTRACT FROM AUTHOR]

Hair, having distinct stages of growth, is a dynamic component of the integumentary system. Nonetheless, derangement in its structure and growth pattern often provides vital clues for the diagnosis of systemic diseases. Assessment of the hair structure by various microscopy techniques is, hence, a valuable tool for the diagnosis of several systemic and cutaneous disorders. Systemic illnesses like Comel-Netherton syndrome, Griscelli syndrome, Chediak Higashi syndrome, and Menkes disease display pathognomonic findings on hair microscopy which, consequently, provide crucial evidence for disease diagnosis. With minimal training, light microscopy of the hair can easily be performed even by clinicians and other health care providers which can, thus, serve as a useful tool for disease diagnosis at the patient's bedside. This is especially true for resource-constrained settings where access and availability of advanced investigations (like molecular diagnostics) is a major constraint. Despite its immense clinical utility and non-invasive nature, hair microscopy seems to be an underutilized diagnostic modality. Lack of awareness regarding the important findings on hair microscopy may be one of the crucial reasons for its underutilization. Herein, we, therefore, present a comprehensive overview of the available methods for hair microscopy and the pertinent findings that can be observed in various diseases. [ABSTRACT FROM AUTHOR]

Objectives: To report the phenotypic, genetic findings and outcome of children with lupus manifestations associated with primary immunodeficiency diseases (PIDs). Methods: Data are retrospectively collected on patients with lupus manifestations and PIDs seen between 1998 and 2019. Data comprised the clinical findings and genetic testing, the response to treatment and the accrual damage related to SLE. Results: A total of 39 patients (22 female) were reviewed. Thirty-four patients had lupus manifestations and six patients with SLE-like manifestations. Genetic analysis was performed in 25 patients. Complement deficiency was the most frequent PIDs; 26 patients were C1q deficient, three patients had C3 deficiency, two patients had C4 deficiency and one patient with heterozygous C8b variant. The other seven patients had different PIDs genetic defects that include SCID caused by PNP deficiency, CGD, CVID (PIK3CD), IL-2RB mutation, DNase II deficiency, STAT1 mutation, ISG15 mutation and Griscelli syndrome type 3. Mucocutaneous lesions, arthritis and lung involvement were the main clinical features. 84.1% experienced recurrent infections. The mean accrual damage was 2.7 ± 2.2. There were five deaths because of infection. Conclusion: This study suggests that patients with lupus manifestations and early onset disease, family history of SLE or recurrent infections should undergo immunological work-up and genetic testing to rule out PIDs. [ABSTRACT FROM AUTHOR]

Background: Granulomatous lymphocytic interstitial lung disease (GLILD) has been increasingly recognized in children affected with primary immunodeficiencies (PIDs). In this study, we aimed to better characterize the spectrum of pediatric PIDs coexisting with GLILD including clinical and immunological predictors, thoracic imaging findings, and histopathologic features. Methods: We respectively reviewed records of six representative cases of children, three of them affected with common variable immunodeficiency (CVID) and three with syndromic immunodeficiencies, in whom a diagnosis of GLILD was established based on clinical, radiological, and histopathologic findings. Clinical and immunological predictors for GLILD were also analyzed in the patients studied. Results: All the children with GLILD had a history of autoimmune phenomena, organ-specific immunopathology, and immune dysregulation. Defective B-cell maturation and deficiency of memory B cells were found in all the children with GLILD. The radiological and histopathological features consistent with the diagnosis of GLILD, granulomatous disease, and lymphoid hyperplasia, were accompanied by chronic airway disease with bronchiectasis in children with CVID and syndromic PIDs. Conclusions: Our study shows that both CVID and syndromic PIDs may be complicated with GLILD. Further studies are required to understand the predictive value of coexisting autoimmunity and immune dysregulation in the recognition of GLILD in children with PIDs. [ABSTRACT FROM AUTHOR]

In this study, a case of Griscelli Syndrome (GS) in a 7 years old girl was reported. The patient initially presented with fever and pancytopenia in laboratory results; after ruling out the malignancies, she went under treatment with the diagnosis of infectious disease and was discharged after two weeks. Nevertheless, ten days after discharge, she developed new symptoms. Due to patient symptoms and general appearance, microscopic analysis of her hair shaft was done, and the abnormal distribution of pigments in the shaft was observed, indicating GS. [ABSTRACT FROM AUTHOR]

Melanosomes are specialized intracellular organelles that produce and store melanin pigments in melanocytes, which are present in several mammalian tissues and organs, including the skin, hair, and eyes. Melanosomes form and mature stepwise (stages I–IV) in melanocytes and then are transported toward the plasma membrane along the cytoskeleton. They are subsequently transferred to neighboring keratinocytes by a largely unknown mechanism, and incorporated melanosomes are transported to the perinuclear region of the keratinocytes where they form melanin caps. Melanocytes also extend several dendrites that facilitate the efficient transfer of the melanosomes to the keratinocytes. Since the melanosome biogenesis, transport, and transfer steps require multiple membrane trafficking processes, Rab GTPases that are conserved key regulators of membrane traffic in all eukaryotes are crucial for skin and hair pigmentation. Dysfunctions of two Rab isoforms, Rab27A and Rab38, are known to cause a hypopigmentation phenotype in human type 2 Griscelli syndrome patients and in chocolate mice (related to Hermansky–Pudlak syndrome), respectively. In this review article, I review the literature on the functions of each Rab isoform and its upstream and downstream regulators in mammalian melanocytes and keratinocytes. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is a rare disease that is characterized by silvery hair and fair skin. It is included in congenital grey hair syndromes, a rare group of autosomal recessive disorders characterized by silvery grey hair and severe multisystem disorders, such as immune system impairment, defects in immunological function, ocular and skeletal alterations, and nervous system defects. Herein, we report a rare case of GS type 1 and highlight the importance of a dermatological and hair examination to make an early diagnosis of these life-threatening diseases. [ABSTRACT FROM AUTHOR]

Griscelli syndrome type 3 is an autosomal recessive disorder caused by mutations in the melanophilin gene and does not have any mucocutaneous or systemic abnormalities other than a pigmentary dilution of skin and hair. We report a case of an 8-year-old girl who presented with silvery grey hair of scalp, eyebrows, eyelashes, and entire body surface with associated universal dyschromia of the skin. After establishing a definite diagnosis of Griscelli syndrome 3, the prognosis was explained and counseling was given. A review of the literature revealed only 27 cases of Griscelli syndrome type 3 in the English language of which only one case by Batrani et al. has reported an associated dyschromia. We report this case to add to the existing literature on this rare condition and to highlight the coexistence of universal dyschromia with Griscelli syndrome type 3. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is a rare autosomal recessive disease that affects hair, skin, and immune system. Here, we describe an 8.5-month-old infant with multiple admissions due to fever, petechial purpura, and several recurrent vomiting episodes with a presumptive diagnosis of recurrent sepsis. He was born from parents with consanguineous marriage. The initial examinations revealed huge splenomegaly and hepatomegaly without any source of infection. Laboratory tests revealed a hemophagocytic lymphohistiocytosis (HLH) like a picture with a high blood level of ferritin in all episodes, but the bone marrow test result was normal. Although he had normal hair and skin pigmentation on physical examination, the accumulation of melanosomes was found in his hair shafts on microscopic investigations. Eventually, a genetic test revealed a mutation in the RAB27A gene, which confirmed GS-II diagnosis. Our case is the first case of GS-II from Iran without any apparent clinical features of GS, such as hypopigmented skin and silvery-gray hair. Therefore, a genetic test, together with the microscopic examination of hair and skin, is necessary for the diagnosis and confirmation of GS-II. Since GS-II is an autosomal recessive disorder and consanguineous marriages are popular in Iran, premarital genetic counseling is recommended for this region. [ABSTRACT FROM AUTHOR]

Type II Griscelli Syndrome (GS) is caused by a mutation in the RAB27A gene and usually manifests with silvery-gray hair, immune deficiency and the development of hemophagocytic lymphohistiocytosis (HLH). A hematopoietic stem cell transplantation is the curative treatment for HLH and reduced-intensity conditioning prevents the morbidity/mortality in the transplantation related to myeloablative conditioning. We report on a 21-month old boy with cerebral involvement of HLH related to GS. [ABSTRACT FROM AUTHOR]

Lysosome‐related organelles (LROs) comprise a diverse group of cell type‐specific, membrane‐bound subcellular organelles that derive at least in part from the endolysosomal system but that have unique contents, morphologies and functions to support specific physiological roles. They include: melanosomes that provide pigment to our eyes and skin; alpha and dense granules in platelets, and lytic granules in cytotoxic T cells and natural killer cells, which release effectors to regulate hemostasis and immunity; and distinct classes of lamellar bodies in lung epithelial cells and keratinocytes that support lung plasticity and skin lubrication. The formation, maturation and/or secretion of subsets of LROs are dysfunctional or entirely absent in a number of hereditary syndromic disorders, including in particular the Hermansky‐Pudlak syndromes. This review provides a comprehensive overview of LROs in humans and model organisms and presents our current understanding of how the products of genes that are defective in heritable diseases impact their formation, motility and ultimate secretion. [ABSTRACT FROM AUTHOR]

We herein illustrate a case of an adult male presenting with silvery hair and generalized guttate hypopigmented macules on a background of diffuse cutaneous hyperpigmentation, since birth. Histopathology showed enlarged melanocytes with abundant melanin. Based on these clinicopathological features, differential diagnoses considered were Griscelli syndrome 3 (GS3) and familial giagantic melanocytosis. GS3 belongs to a group of inherited autosomal recessive (AR) disorders of partial albinism, known as silvery hair syndromes, while familial gigantic melanocytosis (FGM) is a putative disorder of dyschromia with silvery hairs. A pertinent literature search revealed hyperpigmentation or dyschromatosis as a rare manifestation of silvery hair syndromes, especially in dark‐skin populations. A comparative analysis of previously reported cases depicted close morphological similarities between GS3 and FGM. We discuss the uncertainty pertaining to cases described in literature as FGM, to be truly representative of a distinctive entity, or merely a morphological variation of GS3. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is an autosomal-recessive disorder of the vesicle transport and membrane trafficking system first identified by Griscelli et al in 1978. The three types of GS have specific genetic defects and systemic manifestations apart from classic partial pigmentary dilution, resulting in hypopigmentation of skin and silvery hair. GS-II occurs due to a defect in the Rab27a gene and is characterized by primary immune deficiency along with accelerated phases of a hemophagocytic lymphohistiocytosis (HLH) crisis. This rare disorder has been widely studied for dermatological, hematological, and neurological manifestations; however, the oral features and presentations have not been elucidated in detail. This report presents a case of a 4-year-old male with known mutation c.550C > T or p.R184X mutation (ENST00000396307) in Rab27a with oral features. [ABSTRACT FROM AUTHOR]

Background/Objectives: Silvery hair syndrome is a rare, autosomal‐recessive entity characterized by silvery gray hair, eyebrows, and eyelashes and may be associated or not with immunologic or neurologic alterations. Two main types have been recognized: Chediak‐Higashi syndrome and Griscelli syndrome. Hair shaft examination under light microscopy has been a useful tool to differentiate Chediak‐Higashi syndrome from Griscelli syndrome, although distribution of melanin varies according to hair color related to ethnicity. The objective was to compare the pattern of melanin in the skin and with the pattern of melanin distribution in the hair shaft. Methods: Sixteen patients with silvery hair syndrome were selected (Chediak‐Higashi syndrome 5, Griscelli syndrome 11). The distribution of melanin granules in skin and hair shafts was compared and correlated with clinical diagnoses. Results: Chediak‐Higashi syndrome was characterized by small granules of melanin uniformly distributed throughout the thickness of the epidermis. Griscelli syndrome was characterized by an irregular pigment distribution in the epidermal basal layer with large and dense granules alternating with areas lacking melanin pigment. In two cases, study of the hair was not conclusive, but the skin showed the characteristic pattern of Griscelli syndrome. Conclusion: Skin biopsy is a useful tool in differentiating Chediak‐Higashi syndrome from Griscelli syndrome and as a complementary study in cases in which hair shaft pigment distribution does not support the diagnosis, especially in patients with fair hair. The distribution of melanin granules in the skin correlates with that observed in the hair shaft, allowing Chediak‐Higashi syndrome to be differentiated from Griscelli syndrome, at any age. [ABSTRACT FROM AUTHOR]

Macrophage activation syndrome (MAS) is a severe and potentially fatal life-threatening condition associated with excessive activation and expansion of T cells with macrophages and a high expression of cytokines, resulting in an uncontrolled inflammatory response, with high levels of macrophage colony-stimulating factor and causing multiorgan damage. This syndrome is classified into primary (genetic/familial) or secondary forms to several etiologies, such as infections, neoplasias mainly hemopathies or autoimmune diseases. It is characterised clinically by unremitting high fever, pancytopaenia, hepatosplenomegaly, hepatic dysfunction, encephalopathy, coagulation abnormalities and sharply increased levels of ferritin. The pathognomonic feature of the syndrome is seen on bone marrow examination, which frequently, though not always, reveals numerous morphologically benign macrophages exhibiting haemophagocytic activity. Because MAS can follow a rapidly fatal course, prompt recognition of its clinical and laboratory features and immediate therapeutic intervention are essential. However, it is difficult to distinguish underlying disease flare, infectious complications or medication side effects from MAS. Although, the pathogenesis of MAS is unclear, the hallmark of the syndrome is an uncontrolled activation and proliferation of T lymphocytes and macrophages, leading to massive hypersecretion of pro-inflammatory cytokines. Mutations in cytolytic pathway genes are increasingly being recognised in children who develop MAS in his secondary form. We present here a case of Macrophage activation syndrome associated with Griscelli syndrome type 2 in a 3-years-old boy who had been referred due to severe sepsis with non-remitting high fever, generalized lymphoadenopathy and hepato-splenomegaly. Laboratory data revealed pancytopenia with high concentrations of triglycerides, ferritin and lactic dehydrogenase while the bone marrow revealed numerous morphologically benign macrophages with haemophagocytic activity that comforting the diagnosis of a SAM according to Ravelli and HLH-2004 criteria. Griscelli syndrome (GS) was evoked on; consanguineous family, recurrent infection, very light silvery-gray color of the hair and eyebrows, Light microscopy examination of the hair showed large, irregular clumps of pigments characteristic of GS. The molecular biology showed mutation in RAB27A gene confirming the diagnosis of a Griscelli syndrome type 2. The first-line therapy was based on the parenteral administration of high doses of corticosteroids, associated with immunosuppressive drugs, cyclosporine A and etoposide waiting for bone marrow transplantation (BMT). [ABSTRACT FROM AUTHOR]

Hermansky-Pudlak syndrome ( HPS) is a rare autosomal recessive disorder caused by mutations in one of nine genes involved in the packaging and formation of specialized lysosomes, including melanosomes and platelet-dense granules. The cardinal features are pigmentary dilution, bleeding diathesis, and accumulation of ceroid-like material in reticuloendothelial cells. Pulmonary fibrosis induced by tissue damage is seen in the most severe forms, and one subtype is characterized by immunodeficiency. We describe two patients with HPS type 1 and review the updated gene-based classification, clinical features, and recommendations for evaluation and follow-up. [ABSTRACT FROM AUTHOR]

GS2 is a rare autosomal recessive disease characterized by hypopigmentation, variable immunodeficiency with HLH. HSCT is the only curative treatment for GS2. We analyzed the outcome of 10 children with GS2 who underwent HSCT at our center between October 1997 and September 2013. The median age of the patients at transplant was 13.5 months (range, 6-58 months). All of the patients developed HLH before HSCT and received HLH 94 or HLH 2004 protocols. Donors were HLA-identical relatives in 8 patients, HLA-mismatched relatives in 2 patients. Engraftment was achieved in all except one patient. None of the patients developed acute GVHD. Chronic GVHD occurred in one and veno-occlusive disease occurred in four patients. Eight of the patients are under remission without any neurologic sequelae-median time of disease-free survival is 92.4 months. The present study shows successful transplant outcome without long-term neurologic sequelae in patients with GS2 who underwent HSCT from HLA-related donors. [ABSTRACT FROM AUTHOR]

Griscelli syndrome type 2 (GS2) is a rare and often fatal autosomal recessive, hyperinflammatory disorder. It is associated with hypopigmentation of the skin and the hair, resulting in the characteristic pigment accumulation and clumping in the hair shaft. Loss-of-function mutations in RAB27A, resulting from point mutations, short indel, or large deletions, account for all the cases reported to date. However, several GS2 cases originating from Saudi Arabia lack a genetic diagnosis. Here, we report on a new RAB27A genetic anomaly observed in seven Saudi Arabia families that had remained negative after extensive molecular genomic DNA testing. Linkage analysis and targeted sequencing of the RAB27A genomic region in several of these patients led to the identification of a common homozygous tandem duplication of 38 kb affecting exon 2-5 and resulting in a premature stop codon. The pathogenic effect of this duplication was confirmed by a cDNA analysis and functional assays. The identification of microhomology flanking the breakpoint site suggests a possible underlying mechanism. [ABSTRACT FROM AUTHOR]

The article describes the case of a 5-year-old Egyptian girl with Griscelli syndrome (GS), a rare autosomal recessive disorder featuring pigmentary dilution of the hair and skin. Topics discussed include the genetic mutation causing the disease, the clinical features of the proband and her family pedigree, and the result of her sanger sequencing of all exons RAB27A which revealed novel homozygous donor splice-site mutation in intro 5.

Gray hair syndromes are rare syndromes which have an autosomal recessive inheritance and are characterized by pigmentary dilution of skin and hair, defects in immunological function, and nervous system defects. They comprise three disorders namely Chediak-Higashi syndrome (CHS), Griscelli syndrome (GPS), and Elejalde syndrome. Clinically, it is difficult to distinguish these disorders as their clinical features may overlap. Hence, to make a correct diagnosis and differentiate between CHS and GPS light microscopic examination of skin and hair shafts as well as peripheral blood smear evaluations should be done. In cases where the diagnosis is not possible chromosomal analysis for specific mutations can be done. In resource-poor settings where chromosomal analysis is not possible, and light microscopy findings are inconclusive, polarized microscopy can serve as a useful tool to distinguish between CHS and GPS. We report three cases with gray hair syndromes where the diagnosis on light microscopy and polarized microscopy of hair shaft correlated with the bone marrow examination findings and chromosomal analysis, thus emphasizing the importance of a noninvasive, cost-effective, and time-saving alternative in the diagnosis of these syndromes. [ABSTRACT FROM AUTHOR]

Copyright of Okmeydani Tip Dergisi / Medical Journal of Okmeydani Training & Research Hospital is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Silvery hair and severe dysfunction of the central nervous system (Neuroectodermal melanolysosomal disease or Elejalde Syndrome) characterize this rare autosomal recessive syndrome. Main clinical features include silver-leaden hair, bronze skin after sun exposure, and neurologic involvement. Large granules of melanin unevenly distributed in the hair shaft are observed. Abnormal melanocytes and melanosomes and abnormal inclusion bodies in fibroblasts may be present. We report a 10-year-old girl with a silver-leaden (silvery) hair, bronze skin color on sun-exposed areas, generalized hypopigmentation of covered body parts and congenital seizures. The child was the elder of two children born of a consanguineous marriage. The younger sibling, a female neonate, had same clinical presentation. [ABSTRACT FROM AUTHOR]

Griscelli syndrome 2 is a rare autosomal recessive disorder of pigmentary dilution of hair, skin, splenohepatomegaly, pancytopenia, immune and neurologic dysfunction. Clinical course is characterized by recurrent infection triggered by uncontrolled T-lymphocyte and macrophage activation, called hemophagocytic syndrome. Since the primary presentation is with depigmented hair, we attempt to highlight diagnostic difficulties in such cases in developing countries like ours where pigmentary changes in hair and skin are commonly attributed to severe malnutrition. We also evaluated phenotype of all 10 cases of genotype (c.C550T; p.R184X), collected from published literature worldwide and emphasize the potential role of above mutation as hotspot in Southeast Asian region. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Anesthesia & Reanimation is the property of Turkish Society of Anaesthesiology & Reanimation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There is paucity of outcome data for hemophagocytic lymphohistiocytosis (HLH) in infants from India, especially post stem cell transplant (SCT). We report outcome data of eight infants diagnosed with HLH. Mean age was 7.1 months (range 2-11). Mutation analysis was possible in seven patients. One patient had Griscelli syndrome. In three patients, no known mutation could be identified, while in remaining three homozygous mutations in Perforin, Munc and STX11 gene were identified. All were treated as per HLH 2004 protocol. Four died during induction phase. One patient abandoned therapy. Two underwent SCT, while one is awaiting SCT. First patient is alive and disease-free at 22 months postmatched sibling donor SCT. Second underwent unrelated double cord blood transplant, but died 5 months posttransplant due to renal failure. It is feasible to offer SCT for infants with familial HLH in the developing world although barriers like sepsis and disease refractoriness remain. [ABSTRACT FROM AUTHOR]

Griscelli syndrome type 2 (GS2) is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by cutaneous hypopigmentation, immunodeficiency, and hemophagocytic lymphohistiocytosis. We describe 2 brothers who had GS2 with clinically diverse manifestations. The elder brother presented with a purely neurological picture, whereas the younger one presented with fever, pancytopenia, hepatosplenomegaly, and erythema nodosum. Considering that cutaneous hypopigmentation was a common feature between the brothers, genetic analysis for Griscelli syndrome was performed. As the elder sibling had died, mutation analysis was only performed on the younger sibling, which revealed a novel homozygous mutation in the RAB27A gene on chromosome 15 showing a single-base substitution (c.136T>A p.F46I). Both parents were heterozygous for the same mutation. This confirmed the diagnosis of GS2 in the accelerated phase in both siblings. The atypical features of GS2 in these cases are a novel mutation, isolated neurological involvement in one sibling, association with erythema nodosum, and 2 distinct clinical presentations in siblings with the same genetic mutation. [ABSTRACT FROM AUTHOR]

Hemophagocytic syndrome is a rare and potentially fatal disorder characterized by pathological immune activation associated with a primary familial disorder, genetic mutations, or occurring as a sporadic condition. The latter can be secondary to infections, malignancies, or autoimmune diseases. Clinically, patients present signs of severe inflammation, with unremitting fever, cytopenias, spleen enlargement, phagocytosis of bone marrow elements, hypertriglyceridemia, and hypofibrinogenemia. Increased suspicion is determinant to timely initiate treatment in an attempt to alter the natural history. The authors present three clinical cases of this syndrome, with a brief review of the diagnostic criteria and treatment. [ABSTRACT FROM AUTHOR]

Rab27, a member of the small GTPase Rab family, is widely conserved in metazoan, and two Rab27 isoforms, Rab27A and Rab27B, are present in vertebrates. Rab27A was the first Rab protein whose dysfunction was found to cause a human hereditary disease, type 2 Griscelli syndrome, which is characterized by silvery hair and immunodeficiency. The discovery in the 21st century of three distinct types of mammalian Rab27A effectors [synaptotagmin-like protein (Slp), Slp homologue lacking C2 domains (Slac2), and Munc13-4] that specifically bind active Rab27A has greatly accelerated our understanding not only of the molecular mechanisms of Rab27A-mediated membrane traffic (e.g. melanosome transport and regulated secretion) but of the symptoms of Griscelli syndrome patients at the molecular level. Because Rab27B is widely expressed in various tissues together with Rab27A and has been found to have the ability to bind all of the Rab27A effectors that have been tested, Rab27A and Rab27B were initially thought to function redundantly by sharing common Rab27 effectors. However, recent evidence has indicated that by interacting with different Rab27 effectors Rab27A and Rab27B play different roles in special types of secretion (e.g. exosome secretion and mast cell secretion) even within the same cell type. In this review article, I describe the current state of our understanding of the functions of Rab27 effectors in secretory pathways. [ABSTRACT FROM AUTHOR]

Partial albinism with variable immunodeficiency are the two major characteristics of Griscelli syndrome type 2 ( GS-2). This syndrome is usually associated with a high mortality rate and commonly results in early childhood death. Patients suffer from different infections and experience crisis of HLH. HSCT remains the sole curative treatment for GS-2. We prospectively analyzed the outcomes of transplantation with RIC regimen in five patients. The median age at transplantation was 21.6 months (range: 12-30). All of the patients underwent HSCT from HLA-matched related donors. Currently, four patients are cured, and symptoms of recurrent infections and HLH crisis are not seen in them. The only patient who died had undergone HSCT in the accelerated phase of HLH. One patient who developed acute GvHD had a favorable response to therapy. No chronic GvHD occurred in patients. It seems that the use of RIC regimen as a method of transplant preparation is effective and tolerable in this group of patients with various comorbidities. It is recommended to carry out HSCT in these patients at lower ages, before presentations of different infections and HLH crisis. [ABSTRACT FROM AUTHOR]

Class V myosins (MyoV), the most studied unconventional myosins, recognize numerous cargos mainly via the motor's globular tail domain (GTD). Little is known regarding how MyoV-GTD recognizes such a diverse array of cargos specifically. Here, we solved the crystal structures of MyoVa-GTD in its apo-form and in complex with two distinct cargos, melanophilin and Rab interacting lysosomal protein-like 2. The apo-MyoVa-GTD structure indicates that most mutations found in patients with Griscelli syndrome, microvillus inclusion disease, or cancers or in "dilute" rodents likely impair the folding of GTD. The MyoVa-GTD/cargo complex structure reveals two distinct cargo-binding surfaces, one primarily via charge-charge interaction and the other mainly via hydrophobic interactions. Structural and biochemical analysis reveal the specific cargo-binding specificities of various isoforms of mammalian MyoV as well as very different cargo recognition mechanisms of MyoV between yeast and higher eukaryotes. The MyoVa-GTD structures resolved here provide a framework for future functional studies of vertebrate class V myosins. [ABSTRACT FROM AUTHOR]

The article presents abstracts related to dermatopathology in the U.S. including "Cutaneous Clear Cell Sarcoma With Junctional Component and Pagetoid Spread Mimicking Melanoma," by Alison Cheah and Steven Billings, "Griscelli Syndrome: A Case Report and Literature Review," by Alicia Schnebelen and colleagues, and "Paraneoplastic-Like Pemphigus Dress Syndrome Secondary To Traditional Vietnamese Herbal Medicine," by Tandy Repass and Jason Sluzevich.

Background:The motor protein myosin Va plays an important role in the trafficking of intracellular vesicles. Mutation of the Myo5a gene causes Griscelli syndrome type 1 in humans and the dilute phenotype in mice, which are both characterised by pigment dilution and neurological defects as a result of impaired vesicle transport in melanocytes and neuroendocrine cells. The role of myosin Va in platelets is currently unknown. Rab27 has been shown to be associated with myosin Va cargo vesicles and is known to be important in platelet dense granule biogenesis and secretion, a crucial event in thrombus formation. Therefore, we hypothesised that myosin Va may regulate granule secretion or formation in platelets. Methodology/Principal Findings:Platelet function was studied in vitro using a novel Myo5a gene deletion mouse model. Myo5a-/- platelets were devoid of myosin Va, as determined by immunoblotting, and exhibited normal expression of surface markers. We assessed dense granule, α-granule and lysosomal secretion, integrin αIIbβ3 activation, Ca2+ signalling, and spreading on fibrinogen in response to collagen-related peptide or the PAR4 agonist, AYPGKF in washed mouse platelets lacking myosin Va or wild-type platelets. Surprisingly, Myo5a-/- platelets showed no significant functional defects in these responses, or in the numbers of dense and α-granules expressed. Conclusion: Despite the importance of myosin Va in vesicle transport in other cells, our data demonstrate this motor protein has no non-redundant role in the secretion of dense and α-granules or other functional responses in platelets. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is a rare autosomal recessive disorder characterized by partial albinism. Three different types are caused by defects in three different genes. Patients with GS type 1 have primary central nervous system dysfunction, type 2 patients commonly develop hemophagocytic lymphohistiocytosis, and type 3 patients have only partial albinism. While hematopoietic stem cell transplantation is life saving in type 2, no specific therapy is required for types 1 and 3. Patients with GS types 1 and 3 are very rare. To date, only 2 patients with type 3 and about 20 GS type 1 patients, including the patients described as Elejalde syndrome, have been reported. The neurological deficits in Elejalde syndrome were reported as severe neurodevelopmental delay, seizures, hypotonia, and ophthalmological problems including nystagmus, diplopia, and retinal problems. However, none of these patients' clinical progresses were reported. We described here our two new type 1 and two type 3 patients along with the progresses of our previously diagnosed patients with GS types 1 and 3. Our previous patient with GS type I is alive at age 21 without any other problems except severe mental and motor retardation, patients with type 3 are healthy at ages 21 and 24 years having only pigmentary dilution; silvery gray hair, eye brows, and eyelashes. Since prognosis, treatment options, and genetic counseling markedly differ among different types, molecular characterization has utmost importance in GS. [ABSTRACT FROM AUTHOR]

Human skin color is predominantly determined by melanin produced in melanosomes within melanocytes and subsequently distributed to keratinocytes. There are many studies that have proposed mechanisms underlying ethnic skin color variations, whereas the processes involved from melanin synthesis in melanocytes to the transfer of melanosomes to keratinocytes are common among humans. Apart from the activities in the melanogenic rate-limiting enzyme, tyrosinase, in melanocytes and the amounts and distribution patterns of melanosomes in keratinocytes, the abilities of the actinassociated factors in charge of melanosome transport within melanocytes also regulate pigmentation. Mutations in genes encoding melanosome transport-related molecules, such as MYO5A, RAB27A and SLAC-2A, have been reported to cause a human pigmentary disease known as Griscelli syndrome, which is associated with diluted skin and hair color. Thus we hypothesized that process might play a role in modulating skin color variations. To address that hypothesis, the correlations of expression of RAB27A and its specific effector, SLAC2-A, to melanogenic ability were evaluated in comparison with tyrosinase, using human melanocytes derived from 19 individuals of varying skin types. Following the finding of the highest correlation in RAB27A expression to the melanogenic ability, darkly-pigmented melanocytes with significantly higher RAB27A expression were found to transfer significantly more melanosomes to keratinocytes than lightly-pigmented melanocytes in co-culture and in human skin substitutes (HSSs) in vivo, resulting in darker skin color in concert with the difference observed in African-descent and Caucasian skins. Additionally, RAB27A knockdown by a lentivirus-derived shRNA in melanocytes concomitantly demonstrated a significantly reduced number of transferred melanosomes to keratinocytes in co-culture and a significantly diminished epidermal melanin content skin color intensity (DL* = 4.4) in the HSSs. These data reveal the intrinsically essential role of RAB27A in human ethnic skin color determination and provide new insights for the fundamental understanding of regulatory mechanisms underlying skin pigmentation. [ABSTRACT FROM AUTHOR]

Summary The RAB27A/Melanophilin/Myosin-5a tripartite protein complex is required for capturing mature melanosomes in the peripheral actin network of melanocytes for subsequent transfer to keratinocytes. Mutations in any one member of this tripartite complex cause three forms of Griscelli syndrome (GS), each with distinct clinical features but with a similar cellular phenotype. To date, only one case of GS type III (GSIII), caused by mutations in the Melanophilin ( MLPH) gene, has been reported. Here, we report seven new cases of GSIII in three distinct Arab pedigrees. All affected individuals carried a homozygous missense mutation (c.102C>T; p.R35W), located in the conserved Slp homology domain of MLPH, and had hypomelanosis of the skin and hair. We report the first cellular studies on GSIII melanocytes, which demonstrated that MLPH(R35W) causes perinuclear aggregation of melanosomes in melanocytes, typical for GS. Additionally, co-immunoprecipitation assays showed that MLPH(R35W) lost its interaction with RAB27A, indicating pathogenicity of the R35W mutation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In total, 11 consecutive pediatric patients with Griscelli syndrome (GS) type 2, who received allogeneic hematopoietic SCT (aHSCT) at our center between 1993 and 2007, were reviewed. The median age at transplantation was 8.2 months (range, 4–36.3 months) and the median time from diagnosis to transplantation was 3.7 months (range, 1.4–19.5 months). Seven patients developed an accelerated phase and were treated with chemotherapy before transplantation. At the time of transplantation, all patients were in clinical remission. The source of grafts was matched-related marrows in eight patients and partially mismatched unrelated cords in three patients. All patients were engrafted at a median time of 15 days (range, 12–36 days). Grade I–II acute GVHD and veno-occlusive disease occurred in three and one patient, respectively. A total of 10 patients are now alive and disease free at a median of 4.8 years post-HSCT. The post transplant course was complicated by CMV infection in four patients. One patient died in remission from septic shock, 6 months after transplantation. Chimerism studies at the last contact are available for nine patients: six patients have complete donor chimerism and three have stable mixed chimerism. Early aHSCT from matched-related donors or unrelated cord blood for children with GS is feasible. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is a rare autosomal recessive multisystem disorder of pigmentary dilution of skin, silver gray hair, variable immunodeficiency, neurological impairment, and abnormal accumulation of melanosomes in melanocytes. GS type 3 is characterized by hypomelanosis with no immunological and neurological manifestation. Prognosis is very good in type 3 GS and usually require no active intervention, as opposed to type 1 and 2 where early diagnosis and treatment plays a crucial role in patient's survival. The characteristic phenotypic appearance, especially the pigment dilution of the patient's hair, is emphasized here. [ABSTRACT FROM AUTHOR]

Griscelli syndrome (GS) is a rare autosomal recessive disease characterized by silvery hair ('partial albinism'). Three forms exist; GS type 2 (GS2), the most common one, is characterized by severe primary immunodeficiency with acute episodes of hemophagocytic lymphohistiocytosis (HLH) which may be fatal in the absence of hematopoietic stem cell transplantation. A 5-year-old boy with HLH was referred to us because of silvery-gray hair present since birth. Abnormal pigment clumps were observed in the medulla of hair shafts on light microscopy. Electron microscopy of a skin biopsy revealed melanosomes in melanocytes, but not in keratinocytes. Leukocytes were devoid of intracytoplasmic granules on blood smear. Neurological signs were absent. Genotyping revealed a homozygous haplotype for polymorphic markers linked to the RAB27A locus, but no RAB27A mutation. A diagnosis of GS2 was established. The patient received bone marrow transplantation (BMT) from an unrelated donor, and after 72 months he did not show relapse of HLH. The long, uneventful follow-up supports the use of BMT from an unrelated donor if transplantation from a relative is not possible. [ABSTRACT FROM AUTHOR]