A case report of dermatomyositis mimicking myasthenia gravis.

RATIONALE: Patients who have myasthenia gravis or dermatomyositis show clinical signs of muscular weakening. Ocular muscle involvement is uncommon, and symmetrical proximal limb weakness is the typical presentation of dermatomyositis. However, the earliest and most noticeable sign in those with myasthenia gravis is extraocular muscular paralysis. Dermatomyositis is frequently complicated by malignancy, and the common malignancies associated with dermatomyositis vary by region and ethnicity, while thymoma is relatively rare. About 10% to 15% of people with myasthenia gravis have thymoma, which is involved in the etiology of the disease. PATIENT CONCERNS: A 68-year-old female presented with ocular muscle weakness for 10 days that manifested as bilateral blepharoptosis with the phenomenon of "light in the morning and heavy in the evening." Imaging examination showed anterior mediastinal thymic tumor with metastasis. DIAGNOSES: After a thorough physical examination, we discovered bilateral upper limbs with grade IV muscle strength and the typical rash of dermatomyositis. In combination with elevated serum kinase levels and electromyography suggesting myogenic damage, the patient was finally diagnosed as dermatomyositis with multiple metastases of thymoma. INTERVENTIONS: The patient received oral hydroxychloroquine sulfate, topical corticosteroids, and tacrolimus ointment, but these did not work very well. Subsequently, the patient underwent surgery combined with radiotherapy for the thymoma. OUTCOMES: Muscle weakness in the patient improved after effective treatment of tumor, and the rash mostly disappeared. CONCLUSION: Ocular muscle weakness and thymoma are more common in myasthenia gravis, but we cannot ignore the possibility of dermatomyositis. To further establish the diagnosis, a thorough physical examination and laboratory findings are required. Further tumor screening should be performed for patients with dermatomyositis. Early detection and management of possible tumors are essential to the treatment of dermatomyositis linked to malignancies.

Variation at HLA-DPB1 is associated with dermatomyositis in Chinese population.

Dermatomyositis (DM) is a polygenic disorder characterized by inflammation of skeletal muscle and skin. To date, the exact etiopathogenesis of DM remains elusive. To explore the genetic basis of DM, we conducted genome-wide genotyping analysis of 127 patients and 1566 healthy controls by Illumina Human OmniZhongHua-8 BeadChips in the Chinese Han population. We investigated whether the three SNP (rs7750458, rs9501251 and rs9500928) at 6p21.32 in the HLA-DPB1 gene were significantly associated with DM (P < 5 × 10-8 ) and identified two susceptibility loci at 7q34 (PIP, rs9986765, P = 7.45 × 10-7 , odds ratio [OR] = 2.71) and 10q24.2 (CPN1, rs3750716, P = 9.04 × 10-7 , OR = 4.39) with suggestive evidence. We imputed 6674 classical human leukocyte antigen (HLA) alleles, amino acids and SNP from the discovery dataset, and stepwise analysis revealed that HLA-DPB1*17 in class II HLA genes were significantly associated with DM susceptibility. This study represents the first genome-wide association study (GWAS) of DM in the Chinese Han population. For the first time, HLA-DPB1 was found to be associated with DM in this population. Moreover, we identified two novel suggestive susceptibility loci (PIP and CPN1) and confirmed four previously reported genes (DMB, DQA1, DQB1 and DRB1) having potential associations with DM in the Chinese Han population. Our GWAS results in this population should provide important information regarding the genetic etiopathogenesis of DM and facilitate the development of new therapies for the treatment of DM and the prevention of DM progression.

Multiple Eruptive Pyogenic Granulomas Occurring in a Region of Scalded Skin.

We report a case of multiple eruptive pyogenic granulomas after scalding. A 4-year-old girl developed papules and nodules within the scalded areas after a hot soup burn. Although the occurrence of pyogenic granulomas after trauma to the skin is common, multiple lesions of pyogenic granuloma secondary to scalding are rare.

Identification of a missense variant in LNPEP that confers psoriasis risk.

Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To further advance gene discovery, we extended our genome-wide association study data set of 1,139 cases and 2,234 controls and replicated two independent cohorts of 7,200 cases and 10,491 controls. We identified the missense variant rs2303138 (p.Ala763Thr) within the LNPEP gene associated with psoriasis (Pcombined=1.83 × 10(-13), odds ratio=1.16) and validated four previously reported genes: IL28RA, NFKBIA, TRAF3IP2, and CARD14 (9.74 × 10(-11)P9.37 × 10(-5)), which confirmed the involvement of the nuclear factor-κB signaling pathway in psoriasis pathogenesis. LNPEP, also named insulin-responsive aminopeptidase, was identified as an angiotensin IV receptor. Protein function prediction suggested that this missense variant of LNPEP was most likely deleterious. Expression analysis showed that LNPEP was significantly downregulated in psoriatic lesions compared with the control skin (P=1.44 × 10(-6)) and uninvolved patient skin (P=2.95 × 10(-4)). Pathway analysis indicated that LNPEP was involved in the renin-angiotensin system, which also has a key role in cardiovascular disease and diabetes. These results provided genetic evidence that psoriasis might share common mechanisms with hypertension and diabetes, which was consistent with clinical observations. Our study identified a genetic susceptibility factor and provided genetic evidence of insight into psoriasis pathogenesis with the involvement of the renin-angiotensin system pathway.

Psoriasis regression analysis of MHC loci identifies shared genetic variants with vitiligo.

Psoriasis is a common inflammatory skin disease with genetic components of both immune system and the epidermis. PSOR1 locus (6q21) has been strongly associated with psoriasis; however, it is difficult to identify additional independent association due to strong linkage disequilibrium in the MHC region. We performed stepwise regression analyses of more than 3,000 SNPs in the MHC region genotyped using Human 610-Quad (Illumina) in 1,139 cases with psoriasis and 1,132 controls of Han Chinese population to search for additional independent association. With four regression models obtained, two SNPs rs9468925 in HLA-C/HLA-B and rs2858881 in HLA-DQA2 were repeatedly selected in all models, suggesting that multiple loci outside PSOR1 locus were associated with psoriasis. More importantly we find that rs9468925 in HLA-C/HLA-B is associated with both psoriasis and vitiligo, providing first important evidence that two major skin diseases share a common genetic locus in the MHC, and a basis for elucidating the molecular mechanism of skin disorders.

Association of HLA haplotype with keloids in Chinese Hans.

Keloids are common abnormal raised fibroproliferative lesions that can occur following even minor cutaneous trauma. Human leukocyte antigen (HLA) polymorphisms have shown strong association with susceptibility to keloids with different ethnic backgrounds. In this study, the polymerase chain reaction sequence-specific primer method was used to analyze the distribution of HLA haplotype in 192 patients with keloids and 252 healthy control individuals. Controls were matched by gender, age, and race. We compared haplotype between the two groups, and analyzed their association with keloids. The haplotype analysis revealed that three new two-locus haplotypes including B*07-DQB1*0501, B*07-DRB1*15, DQB1*0503-DRB1*15 (P<0.05) were associated with keloids, while two extended haplotypes B*07-Cw*0802-DQB1*0501 (P=0.0063) and Cw*0802-DQB1*0501-DRB1*15 (P=0.0121) were found to be related to keloids. This is the first detailed report to elucidate HLA haplotypes associated with keloids. Our results provide some information for future research on predisposing genes in major histocompatibility complex (MHC) regions in Chinese patients with keloids. In addition, the association of certain HLA haplotypes with susceptibility to keloids would provide clues in choosing proper preventive strategies.

Association analyses identify six new psoriasis susceptibility loci in the Chinese population.

We extended our previous genome-wide association study for psoriasis with a multistage replication study including 8,312 individuals with psoriasis (cases) and 12,919 controls from China as well as 3,293 cases and 4,188 controls from Germany and the United States and 254 nuclear families from the United States. We identified six new susceptibility loci associated with psoriasis in the Chinese study containing the candidate genes ERAP1, PTTG1, CSMD1, GJB2, SERPINB8 and ZNF816A (combined P < 5 × 10⁻8) and replicated one locus, 5q33.1 (TNIP1-ANXA6), previously reported (combined P = 3.8 × 10⁻²¹) in the European studies. Two of these loci showed evidence for association in the German study at ZNF816A and GJB2 with P = 3.6 × 10⁻³ and P = 7.9 × 10⁻³, respectively. ERAP1 and ZNF816A were associated with type 1 (early onset) psoriasis in the Chinese Han population (test for heterogeneity P = 6.5 × 10⁻³ and P = 1.5 × 10⁻³, respectively). Comparisons with the results of previous GWAS of psoriasis highlight the heterogeneity of disease susceptibility between the Chinese and European populations. Our study identifies new genetic susceptibility factors and suggests new biological pathways in psoriasis.

Association of HLA class I alleles with keloids in Chinese Han individuals.

Keloids are benign fibroproliferative dermal tumors of unknown etiology. Some studies have suggested that human HLA status might potentiate development of keloids phenotype. No report has been published about HLA class I alleles associated with keloids in Chinese Han individuals. To investigate the etiology of keloids, the polymerase chain reaction-sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA class I alleles in 192 patients with keloids and 252 healthy controls in a Chinese Han population. The frequencies of HLA-A*03 (6.77% vs 0%, p(c) < 10(-7)), A*25 (10.16% vs 4.56%, p(c) = 0.0111), B*07 (7.81% vs 2.58%, p(c) = 0.0080), and Cw*0802 (19.79% vs 10.32%, p(c) = 0.0004) were significantly increased in keloid patients, whereas the frequency of HLA-A*01 (18.75% vs 38.10%, p(c) < 10(-7)) was highly decreased, compared with that in healthy controls. The A*03-B*07, A*25-B*07, A*03-Cw*0802, A*25-Cw*0802, and B*07-Cw*0802 were found as high-risk haplotypes in developing keloids in this study. No extended haplotype was found to be significantly related to keloids. Through stratified analysis, the association of subgroups (single site/multiple site, severity, and family history) of keloid patients with specific HLA alleles was identified. Our data suggest these alleles may be keloids susceptibility genes or may be in close linkage with the susceptibility genes.

A single-nucleotide polymorphism of the TNFAIP3 gene is associated with systemic lupus erythematosus in Chinese Han population.

Systemic lupus erythematosus (SLE) is a complex systemic disease influenced by genetic and environmental factors. The exact pathogenesis of SLE is still unknown. Recently, several genome-wide association studies (GWA) in European population have found many novel susceptibility genes for SLE including TNFAIP3. In order to examine whether TNFAIP3 is associated with SLE in Chinese Han population, we genotyped one of its non-synonymous mutation SNP rs2230926, showing significant association evidence with SLE in European population, with 1,420 cases and 4,461 controls of Chinese Han by using Sequenom MassArray system. Highly significant association between SNP rs2230926 and SLE of Chinese Han was detected [OR = 1.65, 95% confidence interval (CI): 1.392-1.986, P = 2.03 x 10(-8)]. Interestingly, rs2230926 of TNFAIP3 was also associated with arthritis, ANA and some other subphenotypes of the disease. Our findings suggest that SNP rs2230926 in the TNFAIP3 might be a common genetic factor for SLE within different populations in terms of Chinese Han and European population.

Psoriasis genome-wide association study identifies susceptibility variants within LCE gene cluster at 1q21.

We report the first large genome-wide association study (GWAS) in a Chinese population to identify susceptibility variants for psoriasis using a two-stage case-control design. In the first stage, we carried out a genome-wide association analysis in 1,139 cases and 1,132 controls of Chinese Han ancestry using Illumina Human 610-Quad BeadChips. In the second stage, we took top SNPs forward for replication in two independent samples of 5,182 cases and 6,516 controls of Chinese Han ancestry, and 539 cases and 824 controls of Chinese Uygur ancestry. In addition to the strong replication for two known susceptibility loci MHC (rs1265181, P = 1.93 x 10(-208), OR = 22.62) and IL12B (rs3213094, P(combined) = 2.58 x 10(-26), OR = 0.78), we identified a new susceptibility locus within the LCE gene cluster on 1q21 (rs4085613, P(combined) = 6.69 x 10(-30), OR = 0.76).

Association of HLA-DQA1 and DQB1 genes with vitiligo in Chinese Hans.

BACKGROUND: Vitiligo is an acquired depigmentary disorder of the skin and hair which results from selective destruction of melanocytes. Serological typing and genotyping of human leukocyte antigen (HLA) have shown discrepancies in HLA associations with vitiligo in different ethnic populations. METHODS: Polymerase chain reaction sequence-specific primer (PCR-SSP) method was used to analyze the distribution of HLA-DQA(1) and -DQB(1) alleles among 187 patients with vitiligo and 273 healthy controls through Epi Info version 6 package (Centers for Disease Control and Prevention, Atlanta, GA, USA). RESULTS: The frequencies of HLA-DQA1*0302 (OR = 1.98, P(c) < 0.01), -DQB1*0303 (OR = 3.14, P(c) < 0.001), and -DQB1*0503 (OR = 3.36, P(c) < 0.05) alleles were significantly increased in patients with vitiligo compared with controls, and HLA-DQA(1)*0501 (OR = 0.40, P(c) < 0.01) allele frequency was highly decreased. HLA-DQA1*0302 (OR = 5.19, P(c) < 0.001), -DQA1*0601 (OR = 2.95, P(c) < 0.05), -DQB1*0303 (OR = 4.50, P(c) < 0.001), and -DQB1*0503 (OR = 6.69, P(c) < 0.001) alleles were positively associated, whereas HLA-DQA1*0501 (OR = 0.05, P(c) < 0.001) allele was negatively associated with childhood vitiligo patients, and HLA-DQB1*0303 (OR = 2.76, P(c) < 0.001) allele was positively associated with adult vitiligo patients compared with controls. The frequency of HLA-DQB1*0303 (OR = 3.72, P(c) < 0.001) allele was significantly increased in localized vitiligo patients vs. controls, whereas HLA-DQA1*0302 (OR = 2.47, P(c) < 0.01), -DQB1*0303 (OR = 2.67, P(c) < 0.01), and -DQB1*0503 (OR = 4.46, P(c) < 0.01) allele frequencies were significantly increased and -DQA1*0501 (OR = 0.27, P(c) < 0.01) allele frequency was highly decreased in generalized vitiligo patients. CONCLUSIONS: HLA-DQA1*0302, -DQA1*0601, -DQB1*0303, and -DQB1*0503 alleles could be susceptible alleles of vitiligo, while HLA-DQA1*0501 allele could be a protective allele in Chinese Hans. There may be different genetic backgrounds between vitiligo patients of childhood and adult, localized and generalized.

A novel missense mutation of the ATP2A2 gene in a Chinese family with Darier's disease.

Darier's disease (DD) is an autosomal dominant skin disorder that is characterized by multiple keratotic papules, focal loss of adhesion and abnormal keratinization. Mutations in the ATP2A2 gene encoding sarco/endoplasmic reticulum calcium pumping ATPase type 2 have been identified as the molecular basis of DD. We report here a three-generation family with DD, and examined ATP2A2 gene mutations in this family by direct sequencing. A novel missense mutation A-->G was identified in exon 12, nucleotide 1704, which leads to the substitution of lysine by arginine at codon 514 (K514R). This study contributes to the database on ATP2A2 in DD, and further illustrates the extensive diversity of mutational events that lead to the different phenotypes of DD.

Identification of a locus for dyschromatosis symmetrica hereditaria at chromosome 1q11-1q21.

Dyschromatosis symmetrica hereditaria is a rare autosomal dominant cutaneous disorder characterized by a mixture of hyperpigmented and hypopigmented macules of various sizes on the face and the dorsal aspects of the extremities. The genetic basis for this disease is unknown. We performed a genome-wide search in two large Chinese families to map the chromosome location of the responsible gene. We identified a locus at chromosome 1q11-1q21 with a cumulative maximum two-point LOD score of 8.85 at marker D1S2343 (at recombination fraction=0.00). Haplotype analyses indicated that the disease gene is located within the 11.6 cM region between markers D1S2696 and D1S2635. This is the first locus identified for dyschromatosis symmetrica hereditaria. This study provides a map location for isolation of a disease gene causing dyschromatosis symmetrica hereditaria.

Evidence for a major psoriasis susceptibility locus at 6p21(PSORS1) and a novel candidate region at 4q31 by genome-wide scan in Chinese hans.

Psoriasis is a heterogeneous disease with seven major psoriasis susceptibility loci reported so far on chromosomes 1p, 1q, 3q, 4q, 6p, 17q, and 19p, respectively. To investigate the psoriasis susceptibility loci in Chinese Hans, a genome-wide scan was performed with two-point and multipoint parametric and nonparametric linkage analyses in 61 multiplex families. These families were Chinese Hans residing in east and south-east China, comprising 189 affected and 166 unaffected individuals. We detected evidence for linkage at 6p21 (PSORS1) with nonparametric linkage scores > 3 in the range of 39.9-62.3 cM and a maximum multipoint nonparametric linkage score of 4.58 (p=0.000032). Parametric analysis revealed a maximum two-point heterogeneity lod score of 4.30 with 58% as the proportion of linked families (alpha) and a maximum multipoint heterogeneity lod score of 4.25 (alpha=53%) under the assumption of a dominant model. We could not confirm a previous reported locus (PSORS3) on distal chromosome 4q; however, a region of highly suggestive linkage was identified proximal to this proposed locus. Multipoint nonparametric analysis demonstrated nonparametric linkage scores > 3 throughout a region between 152.5 cM and 165.1 cM (from pter) with a maximum peak of 3.69 (p=0.00033) at 157.9 cM, which locates D4S413. A maximum multipoint heterogeneity lod score of 2.31 (alpha=46%) was reached at 163.1 cM. With two-point parametric linkage analysis, we observed the highest lod score of 2.43 and heterogeneity lod score of 3.94 (alpha=77%) at marker D4S1597. Our results showed that chromosomes 6p and 4q may contain genes involved in the susceptibility to psoriasis vulgaris in a Chinese Han population. Other regions with weaker evidence for linkage could also hide minor susceptibility genes.