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Generalized verrucosis (GV) is a chronic and progressive cutaneous human papillomavirus (HPV) infection resulting in multiple warts and associated with acquired or genetic immune defects. We identified a consanguineous Arab family manifesting GV and recurrent bacterial and viral infections, in association with inflammatory bowel disease (IBD).To identify the mutated gene responsible for GV, recurrent infections and IBD, in this family.Flow cytometry of peripheral blood mononuclear cells was performed, as well as proliferation and cell cycle assays of T cells. Whole exome sequencing was utilized to detect candidate mutated genes, assuming an autosomal recessive mode of inheritance. Skin fibroblasts from a patient, the mother and control were incubated with sorbitol to detect the phosphorylation ability of TAOK2, and a clonogenic assay was performed to assess the survival and proliferative capacity of fibroblasts' colonies.Despite normal immunophenotyping of T and B cells, T cell proliferation upon activation was impaired in a patient compared to a heterozygous family member and a control. Genetic analyses identified a rare homozygous missense variant, c.2098CT (p.R700C) in the TAOK2 gene, segregating with the disease phenotype in the family. TAOK2 encodes the TAO2 kinase, a mitogen activated protein kinase kinase kinase (MAP3K) in the p38-MAPK cascade. The mutation is predicted to disrupt its normal folding and molecular interaction; however, no impairment was observed in TAOK2 kinase activity toward its downstream target, MEK3/6, in patient's fibroblasts. Despite this normal kinase activity, a noticeably higher survival/proliferation of patient's skin fibroblasts was found.A mutation in TAOK2 appears to cause a novel form of primary immunodeficiency, characterized by an impaired T cell proliferation upon activation. This novel cause of GV gives further support to the importance of the p38-MAPK pathway in the immune response against HPV, and possibly also in the pathogenesis of IBD.

Bile acids are synthesized in the liver from cholesterol by a complex series of enzymatic reactions (1). The rate-limiting step in the pathway is the addition of a hydroxyl group to the carbon at the 7 position (C7) of the sterol ring, a reaction catalyzed by the enzyme cholesterol 7α-hydroxylase (CYP7A1). This is followed by isomerization of the Δ5 bond to the Δ4 position and oxidation of the 3β-hydroxyl group to a 3-oxo moiety. Both of these reactions are catalyzed by 3β-hydroxy-Δ5-C27-steroid oxidoreductase (3β-HSD), a 369 amino acid membrane-bound protein in the endoplasmic reticulum that is encoded by HSD3B7 (2). Mutations in HSD3B7 cause 3β-HSD deficiency (#OMIM 607765) (3), a rare autosomal recessive disorder that represents the most common inborn error of bile acid synthesis (2, 4). The disorder was originally described by Clayton et al. (5) in 1987. The diagnosis was established by measuring bile acids in the urine using mass spectrometry in a consanguineous Saudi Arabian family in which several family members presented as neonates with giant cell hepatitis and bridging cirrhosis (5). Over 50 patients with this disorder from at least 40 unrelated families have subsequently been reported (3, 6–16). HSD3B7 was cloned by Schwarz et al. in 2000 (17) and 21 different mutations have been described that cause 3β-HSD deficiency (3, 6, 7, 12, 13). 3β-HSD deficiency usually presents in the neonatal period or in early childhood with cholestatic jaundice, hepatosplenomegaly, steatorrhea, rickets, bleeding and failure to thrive (2). The disease invariably progresses to cirrhosis. In a few cases of late-onset 3β-HSD deficiency, the disease presents in the second or third decades of life (3, 6, 18). Typical clinical features that distinguish 3β-HSD deficiency from other causes of early-onset liver disease include the absence of pruritus, a normal serum level of gamma glutamyl transpeptidase (GGT), and normal or low levels of total serum primary bile acids when measured by routine methods, despite the presence of cholestasis (2, 7, 19, 20). The diagnosis is established by finding high levels of sulfated 3β,7α-dihydroxy-5-cholenoic and 3β,7α-trihydroxy-5-cholenoic acids in the urine or serum (2, 5, 20). Here, we describe an Arab-Iranian family in which several individuals developed cirrhosis of unknown etiology. Homozygosity mapping was used to identify homozygous regions of genomic DNA that were shared by 2 affected cousins but not by an unaffected family member. The two affected individuals in the family that were available for sampling were homozygous for an inactivating mutation in HSD3B7. The family is remarkable for the variability in age of onset and clinical severity of the disease among affected members.

The lines of Blaschko represent a classic pattern of cutaneous mosaicism that can be observed in a wide variety of congenital and acquired skin disorders. This contribution reviews the clinicopathologic spectrum of skin lesions that follow Blaschko lines. Four other patterns of mosaicism are also discussed: blocklike, phylloid, large patches without midline separation, and lateralization. We emphasize the differential diagnoses, clues to correct categorization, and associated findings of inflammatory, hypopigmented, and hyperpigmented lesions with a mosaic distribution. Clinical examples are used to illustrate genetic concepts such as functional X-chromosome mosaicism, type 1 and 2 segmental manifestations of autosomal dominant skin diseases, paradominant inheritance, and twin spotting.

Deficiency of interleukin-36 (IL-36) receptor antagonist (DITRA; OMIM 614204) is a rare autoinflammatory disorder characterized by periodic fever associated with a generalized erythematous and pustular skin rash. A 6-year-old Arab-Palestinian boy presented with a history of periodic fever and unremitting, erythematous, scaly skin rash accompanied by widespread pustules that had been present since the age of one month. The patient's skin lesions were compatible with generalized pustular psoriasis. Sequence analysis revealed a homozygous nonsense mutation, c.28C>T (p.Arg10X) in the IL36RN gene. The patient improved with oral methotrexate in combination with oral and topical corticosteroids. The molecular basis for DITRA has only recently been identified, and the mutation spectrum for this disorder in many populations is still obscure. This paper reports the presence of the c.28C>T mutation in an Arab-Palestinian patient and thus represents the first description of this mutation in a non-Japanese subject.

This study analyzes the histopathological findings in H syndrome, a recently recognized autosomal recessive genodermatosis characterized by indurated, hyperpigmented, and hypertrichotic skin in well-defined anatomical areas accompanied by various systemic manifestations. So far, descriptions of the histopathological skin changes in this disorder, as reported in a few small case series, were inconsistent, leading to diverse clinical interpretations. In an attempt to define standardized, diagnostic, morphological criteria that will distinguish this disorder from other fibrosing conditions, we studied skin biopsies from 10 patients with H syndrome. The characteristic morphology included widespread fibrosis (moderate in dermis and severe in subcutis); striking mononuclear infiltrates consisting mainly of monocyte-derived cells (small CD68 histiocytes and CD34 and FXIIIa dendrocytes) and plasma cells; and thickened, fragmented, and partially calcified elastic fibers, admixed with well-formed psammoma bodies, a previously unrecognized feature in nonneoplastic skin and subcutaneous conditions. In addition, the ultrastructure of CD68 small histiocytes exhibited distended endoplasmic reticulum and scarcity of lysosomes, features typical for fibroblasts but unusual for histiocytes. These unusual findings in the histiocytes pose a question as to their possible role in the fibrotic cascade in this disorder. We conclude that the above findings are essential for the diagnosis of H syndrome and that incisional biopsies are mandatory for recognition of the full spectrum of histopathological findings.

The H syndrome is a recently reported autosomal-recessive disorder characterized by cutaneous hyperpigmentation, hypertrichosis, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, short stature, hallux valgus, and fixed flexion contractures of the toe joints and the proximal interphalangeal joints. Homozygosity mapping in five consanguineous families resulted in the identification of mutations in the SLC29A3 gene, which encodes the equilibrative nucleoside transporter hENT3. Three mutations were found in 11 families of Arab and Bulgarian origin. The finding of several different mutations in a small geographic region implies that the H syndrome might be rather common. The identification of mutations in the SLC29A3 gene in patients with a mild clinical phenotype suggests that this is a largely underdiagnosed condition and strongly suggests that even oligosymptomatic individuals might have the disorder.

Genetic deficiencies provide insights into gene function in humans. Here we describe a patient with a very rare genetic deficiency of ADAM17. We show that the patient's PBMCs had impaired cytokine secretion in response to LPS stimulation, correlating with the clinical picture of severe bacteremia from which the patient suffered. ADAM17 was shown to cleave CD16, a major NK killer receptor. Functional analysis of patient's NK cells demonstrated that his NK cells express normal levels of activating receptors and maintain high surface levels of CD16 following mAb stimulation. Activation of individual NK cell receptors showed that the patient's NK cells are more potent when activated directly by CD16, albeit no difference was observed in Antibody Depedent Cytotoxicity (ADCC) assays. Our data suggest that ADAM17 inhibitors currently considered for clinical use to boost CD16 activity should be cautiously applied, as they might have severe side effects resulting from impaired cytokine secretion.

Background Mutations in various desmosomal proteins were shown to cause inherited forms of cardiomyopathy. Carvajal syndrome (Online Mendelian Inheritance in Man [OMIM] 605676) is characterized by the association of dilated cardiomyopathy, striate palmoplantar keratoderma, and woolly hair. It is caused by homozygous as well as heterozygous mutations in DSP, which encodes the desmosomal plaque protein desmoplakin. An overlapping cardiocutaneous phenotype was also described with homozygous mutations in genes encoding two other desmosomal proteins; plakoglobin (Naxos disease; OMIM 601214) and desmocollin-2 (OMIM 610476). Methods We performed clinical and molecular workups in two consanguineous Arab Palestinian families manifesting an autosomal recessive pattern of inheritance of the above mentioned clinical findings. Whole exome sequencing was employed in the search for the causing mutation. Results Affected family members suffered from biventricular involvement and arrhythmogenic right ventricular dysplasia based on echocardiography and magnetic resonance imaging. One patient who underwent implantation of an implantable cardioverter-defibrillator (ICD) is still alive at the age of 59 years. Whole exome sequencing revealed two novel homozygous mutations in DSP, each affecting one family. Conclusions The association of woolly hair with palmoplantar keratoderma in a child should lead to a cardiac workup in the search for those at increased risk for sudden cardiac death. Early diagnosis and ICD implantation may be lifesaving. Whole exome sequencing should be utilized for rapid genetic analysis since the cardiocutaneous phenotype may result from mutations in one of several genes.

During the last years, a growing number of inherited skin disorders have been recognized to be caused by abnormal function of desmosomal proteins. In the present study, we describe the first female individuals affected with the ectodermal dysplasia/skin fragility syndrome (MIM604536), a rare autosomal recessive disease due to mutations in the PKP1 gene encoding plakophilin 1, a critical component of desmosomal plaque. One patient was shown to carry a homozygous splice site mutation in intron 4. The second patient displayed a homozygous recurrent mutation affecting the acceptor splice site of intron 1. Both mutations were associated with intraepidermal separation, widening of intercellular spaces, and abnormal desmosome ultrastructure, and were found to result in the absence of immunoreactive plakophilin 1 in the epidermis of the affected individuals. These two cases emphasize the role of molecular genetics in the assessment of congenital blistering in newborns and illustrate the importance of proper desmosomal activity for normal epidermis development and function.

The H syndrome (OMIM 612391) is a recently described autosomal recessive disorder characterized by cutaneous hyperpigmentation, hypertrichosis, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, short stature (low height), hyperglycaemia/diabetes mellitus, hallux valgus, and fixed flexion contractures of the toe and finger joints.(1,2) Histologically, there is an inflammatory infiltrate consisting mainly of histiocytes, later replaced by fibrosis of the deep dermis and subcutis.(3) In total, 31 patients have been reported in the literature with the clinical phenotype characteristic of this syndrome.(1-7)

Please cite this paper as: Marie Unna hereditary hypotrichosis caused by a novel mutation in the human hairless transcript. Experimental Dermatology 2010; 19: e320–e322. Abstract: Recently the causes for various forms of hypotrichosis and atrichia have been identified, increasing our understanding of the pathways involved in hair cycling and morphogenesis. Loss-of-function mutations of an inhibitory upstream ORF in the human hairless transcript were found as the cause for autosomal dominant Marie Unna hereditary hypotrichosis. At present, only two studies identified several pathogenic mutations. We ascertained a Jewish Ashkenazi family with hypotrichosis simplex of the Marie Unna type in a mother and her two children. Sequencing of the upstream ORF U2HR in the 5′ UTR of the hairless gene resulted in the identification of a novel heterozygous missense mutation c.74C > T resulting in the amino acid change p.P25L. Functional assays confirmed that this mutation led to increased translation of the main HR ORF. This finding extends the mutations’ spectrum of U2HR, and emphasizes its major role in hair growth.

We present a 10-year-old girl with typical clinical features of H syndrome. Complete agenesis of the inferior vena cava was found on echocardiography and radiologic studies. Mutation analysis of the SLC29A3 gene revealed a novel nonsense mutation. This unique case extends the clinical and mutation spectrum associated with H syndrome and underlines the importance of routine cardiac screening in this disorder.

H syndrome is a recently described autosomal recessive disorder characterized by indurated, hyperpigmented, and hypertrichotic cutaneous plaques, mainly involving the lower abdomen and lower extremities. Associated systemic manifestations include hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, low height, and hyperglycemia. H syndrome is caused by mutations in the gene SLC29A3, which encodes hENT3, a member of the human equilibrative nucleoside transporter family. Histopathologically, cutaneous lesions of H syndrome consist of dermal and subcutaneous fibrosis with inflammatory infiltrate mostly composed of large histiocytes, some plasma cells, and scattered lymphoid aggregates. Recently, histopathologic and immunohistochemical studies have demonstrated that the immunophenotype of the histiocytes infiltrating the skin of a patient with H syndrome is similar to that of the lesions of Rosai-Dorfman disease. Furthermore, mutations in SLC29A3 gene have also been demonstrated in patients described as having an inherited form of Rosai-Dorfman disease, named Faisalabad histiocytosis or familial Rosai-Dorfman disease. We describe emperipolesis in the cutaneous lesions of a patient with H syndrome, further supporting the relationship between Rosai-Dorfman disease and H syndrome.

Purpose To describe the spectrum of radiological findings in 12 patients with H syndrome. Patients and Methods Various radiological examinations of 12 patients (M=9, F=3) with H syndrome were reviewed. Results Symmetrical thickening of the skin of the subcutaneous tissue at the lower half of the body (n=9, 75%), with retracted micropenis in males (n=5, 55%). Groin varices (n=5, 42%) and lymphadenopathy (n=5, 42%) were observed in severe cases. Severe symmetrical flexion deformities of the fingers (n=7, 58%) were relatively common. Conclusion Skin thickening with subcutaneous fat infiltration and deformities of the hands and feet are typical for H syndrome.

A seven-year-old girl was born with red, scaly skin that later evolved into hypopigmentation and follicular atrophoderma in a widespread distribution that followed Blaschko lines. She also had patchy, scarring alopecia, left microphthalmia, bilateral cataracts, dysmorphic facies, short stature, hip dysplasia, and vertebral abnormalities. An elevated plasma 8(9)-cholestenol level confirmed the diagnosis of Conradi-Hünermann-Happle syndrome, which is caused by mutations in the emopamil binding protein (EBP) gene. This reports highlights the evolution of clinical findings over time in this X-linked dominant form of chondrodysplasia punctata.

3 páginas, 2 figuras., H syndrome (OMIM 612391) is a recently described autosomal-recessive genodermatosis with systemic manifestations. The disease is characterized by the major clinical findings of progressive cutaneous hyperpigmentation and hypertrichosis located mainly over the lower limbs and lower abdomen, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, low height and hyperglycemia/diabetes mellitus [1] and [2]. The major histopathological findings include dermal infiltrate consisting mainly of histiocytes, later replaced by dermal and subcutaneous fibrosis [3]. Recently, we [2] and others [4] found that missense, nonsense, compound and deletion mutations in the SLC29A3 gene are responsible for this unique clinical picture. The SLC29A3 gene encodes the human equilibrative nucleoside transporter (hENT3), which mediates passive sodium-independent transport of nucleosides [5]. The exact cellular localization of hENT3, endosomal/lysosomal [6] or mitochondrial [7], and its function with relation to the H syndrome is still unclear. Here, we report two new cases of H syndrome, of Spanish and of Arab origin and describe two novel missense mutations., Authority for Research and Development, Hebrew University of Jerusalem (A.Z.), the Hadassah Medical Center physician scientist program and the Hadassah-Hebrew University Joint Research Fund (V.M.P.)

Background The association of cutaneous hyperpigmented, hypertrichotic, and indurated patches associated with hearing loss, short stature, cardiac anomalies, hepatosplenomegaly, scrotal masses, and hypogonadism has not, to our knowledge, been previously recognized as a disease entity. Objective We describe 10 patients with the above-mentioned findings. Methods Patients were clinically examined and extensive laboratory evaluation was performed. Results We describe 10 patients from 6 Arab consanguineous families with hyperpigmented, hypertrichotic, and indurated cutaneous patches involving the middle and lower parts of their bodies. In addition, patients displayed short stature, sensorineural hearing loss, cardiac anomalies, hepatosplenomegaly, and scrotal masses. Laboratory evaluation revealed growth hormone deficiency and hypergonadotropic hypogonadism with azoospermia. Cutaneous histopathologic examination showed hyperpigmentation of the basal layer with seborrheic-keratosis-like acanthosis, histiocytic infiltration, and a perivascular mononuclear infiltrate with plasma cells and mast cells throughout the dermis and subcutaneous fat. Comparison with several patients, recently reported in the medical literature, with similar cutaneous findings is made. Limitations Laboratory evaluation in some patients was incomplete because of lack of cooperation. Conclusions We suggest that our patients represent a novel multisystemic autosomal recessive inherited disorder. We call this constellation of symptoms the "H syndrome."

The skin is an organ in which direct contact with viruses, solar UV irradiation and increased susceptibility to immune suppression gather to support viral tumorigenesis. Viruses transform keratinocytes by activation of cancer-promoting genes. Viral proteins may directly act as oncogenes that drive cells to proliferate or generate inflammatory responses and cause regeneration of injured cells that eventually lead to malignant transformation. Accelerated viral carcinogenesis is observed in the immune-deficient host. Decreased T-cell reactivity and lower number of antigen-presenting cells in the skin assist in viral escape and emergence of skin tumors. Three pathogenic human viruses associated with skin neoplasms are described: human papilloma virus (HPV), Kaposi's sarcoma (KS)-associated herpesvirus and human T-cell leukemia virus type 1. HPV was linked to squamous cell carcinoma (SCC) of the skin after its role in SCC of the cervix has been discovered. In the rare autosomal recessive epidermodysplasia verruciformis, an increased susceptibility to specific HPV strains initially results in widespread wart infection and later in life in the development of SCC over the sun-exposed skin. The role of HPV in nonmelanoma skin cancer of immune competent hosts is more difficult to prove. The discovery of human herpesvirus 8 as the causative pathogen of KS was made following the AIDS epidemic, and its role in all clinical variants of this tumor was confirmed. KS-associated herpesvirus exerts its tumorigenic effect through a wide repertoire of genes that regulate angiogenesis, inflammation, and cell cycle. Human T-cell leukemia virus type 1 causes adult T-cell leukemia and is often associated with skin eruptions that share common features with cutaneous T-cell lymphoma. In summary, studies of oncogenic viruses shed light on molecular mechanisms leading to tumor formation and aid in recognition of new pathways of carcinogenesis.

Background Telangiectases are abnormal dilatations of end vessels in the subpapillary plexus of the papillary dermis. Hereditary benign telangiectasia (HBT) (OMIM 187260) is a genetic skin disorder, characterized by multiple cutaneous telangiectases appearing in the first years of life in various locations. Several familial cases of HBT have been described displaying autosomal dominant inheritance. In some of the described pedigrees, telangiectases are limited to sun-exposed areas, whereas in others lesions are randomly distributed over the body. The disorder has been previously mapped to a 7Mb interval on chromosome 5q14 ( CMC1 locus) in an Italian pedigree with randomly distributed telangiectases. Objectives A large pedigree of HBT with photodistributed lesions is described. We sought to determine whether photodistributed HBT is linked to the CMC1 locus. Methods In all, 35 family members were examined. DNA was extracted from blood and saliva samples. Linkage analysis to CMC1 locus on chromosome 5q14 was screened by using 3 polymorphic markers. Results In all, 23 family members were found to have variable numbers of cutaneous radiating macular telangiectases, measuring 1 to 3 cm and distributed over the face, back of the hands, and forearms. HBT in this family is inherited in an autosomal dominant pattern with incomplete penetrance. Linkage to the CMC1 locus was excluded. Limitation Only one family, although very large, was studied in this project. Conclusions Clinical and genetic heterogeneity is evident in HBT. Photodistributed HBT is not related pathogenically to capillary malformations or to randomly distributed hereditary telangiectases and should be recognized as a separate entity.

The skin is an organ in which direct contact with viruses, solar UV irradiation and increased susceptibility to immune suppression gather to support viral tumorigenesis. Viruses transform keratinocytes by activation of cancer-promoting genes. Viral proteins may directly act as oncogenes that drive cells to proliferate or generate inflammatory responses and cause regeneration of injured cells that eventually lead to malignant transformation. Accelerated viral carcinogenesis is observed in the immune-deficient host. Decreased T-cell reactivity and lower number of antigen-presenting cells in the skin assist in viral escape and emergence of skin tumors. Three pathogenic human viruses associated with skin neoplasms are described: human papilloma virus (HPV), Kaposi’s sarcoma (KS)-associated herpesvirus and human T-cell leukemia virus type 1. HPV was linked to squamous cell carcinoma (SCC) of the skin after its role in SCC of the cervix has been discovered. In the rare autosomal recessive epidermodysplasia verruciformis, an increased susceptibility to specific HPV strains initially results in widespread wart infection and later in life in the development of SCC over the sun-exposed skin. The role of HPV in nonmelanoma skin cancer of immune competent hosts is more difficult to prove. The discovery of human herpesvirus 8 as the causative pathogen of KS was made following the AIDS epidemic, and its role in all clinical variants of this tumor was confirmed. KS-associated herpesvirus exerts its tumorigenic effect through a wide repertoire of genes that regulate angiogenesis, inflammation, and cell cycle. Human T-cell leukemia virus type 1 causes adult T-cell leukemia and is often associated with skin eruptions that share common features with cutaneous T-cell lymphoma. In summary, studies of oncogenic viruses shed light on molecular mechanisms leading to tumor formation and aid in recognition of new pathways of carcinogenesis.

Nonmelanoma skin cancer (NMSC) is the most common type of human cancer. Solar ultraviolet radiation (UVR) is the main causative factor in the development of NMSC. UVR plays a variety of roles in the induction of skin cancers. It can serve as a complete carcinogen or as a promoter of carcinogenesis. The typical UV-induced DNA damage is the generation of dimeric photoproducts between adjacent pyrimidine bases. Tumor suppressor gene p53 is a common target of UVR-induced mutations. There is a proliferative advantage of p53 mutant keratinocytes over normal keratinocytes that eventuates in neoplastic transformation. While UVB causes considerable DNA damage in the skin, UVA has only recently been shown to induce pyrimidine dimers and oxygen and nitrogen reactive species which damage DNA, proteins and lipids. The immunosuppressive effect of UVR contributes to its carcinogenic activity. Finally, any one of these effects of UVR may contribute to the induction of skin cancers by other agents such as X-rays, viruses, or chemical carcinogens. The mechanism by which UVR leads to cutaneous malignant melanoma is less clear and it may be a cofactor rather than an initiator of this tumor. Primary prevention of UVR exposure is the most effective means of reducing UVR carcinogenesis. Systemic retinoids may influence the appearance of new tumors in patient populations at increased risk of developing NMSC such as xeroderma pigmentosum and organ transplant recipients, but their efficacy is hindered by their side effects.

Background Human β-mannosidosis, a rare disorder of oligosaccharide catabolism, results from a deficiency of β-mannosidase activity. So far, mutational analysis has been performed in only seven families and revealed 11 mutations in the MANBA gene which encodes the enzyme β-mannosidase. Objectives We report here a 36-year-old Arab female with β-mannosidosis who presented with mental retardation and multiple angiokeratomas. We describe in this patient a novel null mutation and review the previously reported MANBA gene mutations and their clinical correlations. Methods Histopathology, ultrastructural analysis, and enzyme assays were performed. Sequencing of cDNA and genomic DNA analysis was conducted in a search for a mutation in the MANBA gene. Results Histopathology of a skin biopsy specimen from the patient showed the characteristic findings of angiokeratoma. Electron microscopy showed cytoplasmic vacuolation. Enzymatic activity of β-mannosidase in the patient's serum, leukocytes, and fibroblasts was less than 1% of control values. Sequencing of the MANBA cDNA revealed a G→A transition in exon 6 at nucleotide position c.693, resulting in the formation of a stop codon (W231X). Limitations Only one family was studied. Conclusions A new case of human β-mannosidosis is presented and the first MANBA gene mutation from Arab ancestry is reported. Reviewing the reported MANBA gene mutations does not reveal a clear genotype–phenotype correlation. The importance of angiokeratoma corporis diffusum as the clue to the diagnosis of β-mannosidosis and other lysosomal storage diseases is emphasized.

Lipoid proteinosis (LP) (OMIM 247100) is a rare, autosomal recessive disorder. Recent studies have shown that LP is the result of reduced expression of the extracellular matrix protein gene (ECM-1), in which loss-of-function mutations have been described. In the present report, we describe a large consanguineous family with LP. We identified a homozygous splice-site mutation in intron 1 (IVS1 + 1GC) in three clinically affected patients. This is the first splice-site mutation reported in LP and is the most 5′ of all ECM-1 mutations described thus far. It is predicted to result in the removal of the translation initiation site, thus ablating all three known ECM-1 isoforms (ECM-1a, ECM-1b, and ECM-1c). In addition, we found a novel splicing variant that is not associated with the disease (DQ010946) and results in the generation of a short, prematurely terminating transcript. This case further emphasizes the role of ECM-1 in LP and highlights the unresolved genotype–phenotype correlation in this disease.

Systemic sclerosis (scleroderma, SSc) is an incurable autoimmune disease with high morbidity and mortality rates. Here, we conducted a population-scale single-cell genomic analysis of skin and blood samples of 56 healthy controls and 97 SSc patients at different stages of the disease. We found immune compartment dysfunction only in a specific subtype of diffuse SSc patients but global dysregulation of the stromal compartment, particularly in a previously undefined subset of LGR5(+)-scleroderma-associated fibroblasts (ScAFs). ScAFs are perturbed morphologically and molecularly in SSc patients. Single-cell multiome profiling of stromal cells revealed ScAF-specific markers, pathways, regulatory elements, and transcription factors underlining disease development. Systematic analysis of these molecular features with clinical metadata associates specific ScAF targets with disease pathogenesis and SSc clinical traits. Our high-resolution atlas of the sclerodermatous skin spectrum will enable a paradigm shift in the understanding of SSc disease and facilitate the development of biomarkers and therapeutic strategies.