Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

Systemic retinoids in the management of ichthyoses and related skin types

The term retinoid includes both natural and synthetic derivatives of vitamin A. Retinoid-containing treatments have been used since ~1550BC by the early Egyptians. Treatment of ichthyosiform disorders with retinoids dates back at least to the 1930s. Early use of high-dose vitamin A demonstrated efficacy, but because vitamin A is stored in the liver, toxicity limited usefulness. Interest turned to synthetic retinoids in an effort to enhance efficacy and limit toxicity. Acetretin, isotretinoin and, in the past etretinate, have provided the most effective therapy for ichthyosiform conditions. They have been used for a variety of ages, including in newborns with severe ichthyosis and for decades in some patients. Careful surveillance and management of mucous membrane, laboratory, skeletal, and teratogenic side effects has made systemic retinoids the mainstay of therapy for ichthyosis and related skin types.

The chromosome 2p21 region harbors a complex genetic architecture for association with risk for renal cell carcinoma

In follow-up of a recent genome-wide association study (GWAS) that identified a locus in chromosome 2p21 associated with risk for renal cell carcinoma (RCC), we conducted a fine mapping analysis of a 120 kb region that includes EPAS1. We genotyped 59 tagged common single-nucleotide polymorphisms (SNPs) in 2278 RCC and 3719 controls of European background and observed a novel signal for rs9679290 [P = 5.75 × 10(-8), per-allele odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.17-1.39]. Imputation of common SNPs surrounding rs9679290 using HapMap 3 and 1000 Genomes data yielded two additional signals, rs4953346 (P = 4.09 × 10(-14)) and rs12617313 (P = 7.48 × 10(-12)), both highly correlated with rs9679290 (r(2) > 0.95), but interestingly not correlated with the two SNPs reported in the GWAS: rs11894252 and rs7579899 (r(2) < 0.1 with rs9679290). Genotype analysis of rs12617313 confirmed an association with RCC risk (P = 1.72 × 10(-9), per-allele OR = 1.28, 95% CI: 1.18-1.39) In conclusion, we report that chromosome 2p21 harbors a complex genetic architecture for common RCC risk variants.

A genome-wide association study identifies a novel susceptibility locus for renal cell carcinoma on 12p11.23

Renal cell carcinoma (RCC) is the most lethal urologic cancer. Only two common susceptibility loci for RCC have been confirmed to date. To identify additional RCC common susceptibility loci, we conducted an independent genome-wide association study (GWAS). We analyzed 533 191 single nucleotide polymorphisms (SNPs) for association with RCC in 894 cases and 1516 controls of European descent recruited from MD Anderson Cancer Center in the primary scan, and validated the top 500 SNPs in silico in 3772 cases and 8505 controls of European descent involved in the only published GWAS of RCC. We identified two common variants in linkage disequilibrium, rs718314 and rs1049380 (r(2) = 0.64, D ' = 0.84), in the inositol 1,4,5-triphosphate receptor, type 2 (ITPR2) gene on 12p11.23 as novel susceptibility loci for RCC (P = 8.89 × 10(-10) and P = 6.07 × 10(-9), respectively, in meta-analysis) with an allelic odds ratio of 1.19 [95% confidence interval (CI): 1.13-1.26] for rs718314 and 1.18 (95% CI: 1.12-1.25) for rs1049380. It has been recently identified that rs718314 in ITPR2 is associated with waist-hip ratio (WHR) phenotype. To our knowledge, this is the first genetic locus associated with both cancer risk and WHR.

Von Hippel-Lindau (VHL) inactivation in sporadic clear cell renal cancer: associations with germline VHL polymorphisms and etiologic risk factors

Renal tumor heterogeneity studies have utilized the von Hippel-Lindau VHL gene to classify disease into molecularly defined subtypes to examine associations with etiologic risk factors and prognosis. The aim of this study was to provide a comprehensive analysis of VHL inactivation in clear cell renal tumors (ccRCC) and to evaluate relationships between VHL inactivation subgroups with renal cancer risk factors and VHL germline single nucleotide polymorphisms (SNPs). VHL genetic and epigenetic inactivation was examined among 507 sporadic RCC/470 ccRCC cases using endonuclease scanning and using bisulfite treatment and Sanger sequencing across 11 CpG sites within the VHL promoter. Case-only multivariate analyses were conducted to identify associations between alteration subtypes and risk factors. VHL inactivation, either through sequence alterations or promoter methylation in tumor DNA, was observed among 86.6% of ccRCC cases. Germline VHL SNPs and a haplotype were associated with promoter hypermethylation in tumor tissue (OR = 6.10; 95% CI: 2.28-16.35, p = 3.76E-4, p-global = 8E-5). Risk of having genetic VHL inactivation was inversely associated with smoking due to a higher proportion of wild-type ccRCC tumors [former: OR = 0.70 (0.20-1.31) and current: OR = 0.56 (0.32-0.99); P-trend = 0.04]. Alteration prevalence did not differ by histopathologic characteristics or occupational exposure to trichloroethylene. ccRCC cases with particular VHL germline polymorphisms were more likely to have VHL inactivation through promoter hypermethylation than through sequence alterations in tumor DNA, suggesting that the presence of these SNPs may represent an example of facilitated epigenetic variation (an inherited propensity towards epigenetic variation) in renal tissue. A proportion of tumors from current smokers lacked VHL alterations and may represent a biologically distinct clinical entity from inactivated cases.

Prior history of non-melanoma skin cancer is associated with increased mortality in patients with chronic lymphocytic leukemia

We investigated whether a previous diagnosis of non-melanoma skin cancer among chronic lymphocytic leukemia patients is a predictor of poor outcome. Using the Swedish Cancer Registry, we conducted a population-based study to evaluate the survival patterns among chronic lymphocytic leukemia patients with and without non-melanoma skin cancer. Cox proportional hazards regression models were used and Kaplan-Meier curves were constructed. Of a total of 12,041 chronic lymphocytic leukemia cases identified, 236 cases, including 111 squamous cell cancer, had a prior history of non-melanoma skin cancer. Chronic lymphocytic leukemia patients with a prior history of non-melanoma skin cancer had a 1.29-fold (95% CI 1.10-1.52; p=0.0024) increased risk of dying; and those with a history of squamous cell cancer had a further elevated 1.86-fold (95% CI 1.46-2.36; p<0.0001) risk of dying. Kaplan-Meier plots showed that patients with a history of non-melanoma skin cancer, particularly those with squamous cell cancer, had significantly poorer survival than chronic lymphocytic leukemia patients without non-melanoma skin cancer (p<0.0001; log-rank test). Non-melanoma skin cancer may be a novel clinical predictor of worse chronic lymphocytic leukemia outcome.

Cutaneous appendageal carcinoma incidence and survival patterns in the United States: a population-based study

OBJECTIVE

To examine incidence patterns of patients diagnosed as having cutaneous appendageal carcinoma (CAC).

DESIGN

Population-based study using the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute data from 1978 through 2005.

PARTICIPANTS

A total of 1801 subjects from SEER 16 registries (2001-2005) for incidence analyses, 2228 from SEER 9 registries (1987-2005) for trend analysis, and 1984 subjects (1992-2004) for survival analysis.

MAIN OUTCOME MEASURE

Incidence rates (IRs) per 1 million person-years according to anatomic site, race, sex, age, and histologic type.

RESULTS

Cutaneous appendageal carcinomas are uncommon (age-adjusted IR, 5.1 per 1 million person-years), with the IR among men statistically significantly higher than women (6.3 vs 4.2, respectively; male to female IR ratio 1.51; P < .001). Hispanic whites (IR, 3.7), blacks (IR, 3.5), and Asian/Pacific Islanders (IR, 2.5) all had significantly lower IRs than non-Hispanic whites (IR, 5.7) (P < .001). Apocrine-eccrine carcinoma overall was the most common category (IR, 2.6), and the IR was highest among non-Hispanic white (IR, 2.8) compared with other ethnic/racial groups (P < .001). Cutaneous appendageal carcinomas IRs rose 100-fold with age, from 0.37 among those aged 20 to 29 years to 37.3 among those 80 years or older. From 1978-1982 to 2002-2005, the CAC IRs increased 150%, from 2.0 to 5.0; the apocrine-eccrine carcinoma and the sebaceous carcinoma IRs rose 170%, from 1.0 to 2.7, and 217%, from 0.6 to 1.9, respectively. Five-year relative survival rates overall were 99% for localized and 43% for distant disease.

CONCLUSIONS

Cutaneous appendageal carcinomas are rare tumors with IRs that vary by sex and racial/ethnic group. Cutaneous appendageal carcinoma IRs are increasing in the United States, especially for sebaceous carcinoma, perhaps related to improved recognition and classification, but factors such as UV exposure and immunosuppression may also play a role.

The folliculin mutation database: an online database of mutations associated with Birt-Hogg-Dubé syndrome

The folliculin gene (FLCN), also known as BHD, is the only known susceptibility gene for Birt-Hogg-Dubé syndrome. BHDS is the autosomal dominant predisposition to the development of follicular hamartomas, lung cysts, spontaneous pneumothorax, and/or kidney neoplasms. To date, 53 unique germline mutations have been reported. FLCN mutation detection rate is 88%. FLCN encodes a predicted 579-amino acid protein, designated folliculin that is highly conserved between humans and homologs in mice, Drosophila, and C. elegans. We developed the first online database detailing all FLCN variants identified in our laboratory and reported in the literature. The FLCN database applies, and assists researchers in applying HGVS nomenclature guidelines. To date, the FCLN database includes 84 variants: 53 unique germline mutations and 31 SNPs. The majority of FLCN germline mutations are predicted to produce a truncated folliculin, resulting in loss of function. The FLCN mutations consist of: 45% (24/53) deletions, 32% (17/53) substitutions (10 putative-splice site, 5 nonsense, and 2 missense), 15% (8/53) duplications, 6% (3/53) insertion/deletions and 2% (1/53) insertions. The database strives to systematically unify current knowledge of FLCN variants and will be useful to geneticists and genetic counselors while also providing a rapid and systematic resource for investigators.

Update of cylindromatosis gene (CYLD) mutations in Brooke-Spiegler syndrome: novel insights into the role of deubiquitination in cell signaling

Germline mutations in the cylindromatosis (CYLD) gene have been described in families with cylindromas, trichoepitheliomas, and/or spiradenomas. Brooke-Spiegler syndrome (BSS) is the autosomal dominant predisposition to skin appendageal neoplasms including cylindromas, trichoepitheliomas, and/or spiradenomas. We review the clinical features, molecular genetics, and the animal models of BSS. To date, a total of 51 germline CYLD mutations have been reported, occurring in exons 9-20, in 73 families with diverse ethnic and racial backgrounds. Of 51 mutations, 86% are expected to lead to truncated proteins. The seven missense mutations reported to date occur only within the ubiquitin (Ub)-specific protease (USP) domain of the CYLD protein and most are associated exclusively with multiple familial trichoepithelioma (MFT). CYLD functions as a tumor suppressor gene. CYLD encodes a deubiquitinating (DUB) enzyme that negatively regulates the nuclear factor (NF)-kappaB and c-Jun N-terminal kinase (JNK) pathways. CYLD DUB activity is highly specific for lysine 63 (K63)-linked Ub chains but has been shown to act on K48-linked Ub chains as well. In 2008, the CYLD USP domain was crystallized, revealing that the truncated Fingers subdomain confers CYLD's unique specificity for K63-linked Ub chains. Recent work using animal models revealed new roles for CYLD in immunity, lipid metabolism, spermatogenesis, osteoclastogenesis, antimicrobial defense, and inflammation.

Transglutaminase-1 gene mutations in autosomal recessive congenital ichthyosis: summary of mutations (including 23 novel) and modeling of TGase-1

Autosomal recessive congenital ichthyosis (ARCI) is a heterogeneous group of rare cornification diseases. Germline mutations in TGM1 are the most common cause of ARCI in the United States. TGM1 encodes for the TGase-1 enzyme that functions in the formation of the cornified cell envelope. Structurally defective or attenuated cornified cell envelop have been shown in epidermal scales and appendages of ARCI patients with TGM1 mutations. We review the clinical manifestations as well as the molecular genetics of ARCI. In addition, we characterized 115 TGM1 mutations reported in 234 patients from diverse racial and ethnic backgrounds (Caucasion Americans, Norwegians, Swedish, Finnish, German, Swiss, French, Italian, Dutch, Portuguese, Hispanics, Iranian, Tunisian, Moroccan, Egyptian, Afghani, Hungarian, African Americans, Korean, Japanese and South African). We report 23 novel mutations: 71 (62%) missense; 20 (17%) nonsense; 9 (8%) deletion; 8 (7%) splice-site, and 7 (6%) insertion. The c.877-2A>G was the most commonly reported TGM1 mutation accounting for 34% (147 of 435) of all TGM1 mutant alleles reported to date. It had been shown that this mutation is common among North American and Norwegian patients due to a founder effect. Thirty-one percent (36 of 115) of all mutations and 41% (29 of 71) of missense mutations occurred in arginine residues in TGase-1. Forty-nine percent (35 of 71) of missense mutations were within CpG dinucleotides, and 74% (26/35) of these mutations were C>T or G>A transitions. We constructed a model of human TGase-1 and showed that all mutated arginines that reside in the two beta-barrel domains and two (R142 and R143) in the beta-sandwich are located at domain interfaces. In conclusion, this study expands the TGM1 mutation spectrum and summarizes the current knowledge of TGM1 mutations. The high frequency of mutated arginine codons in TGM1 may be due to the deamination of 5' methylated CpG dinucleotides.

Hereditary kidney cancer: unique opportunity for disease-based therapy

Kidney cancer is not a single disease; it is comprised of several different types of cancer, each with a different histology, with a different clinical course, caused by a different gene, and responding differently to therapy. The VHL gene is the gene for the hereditary cancer syndrome, von Hippel-Lindau, as well as for the common form of sporadic, noninherited, clear cell kidney cancer. Understanding the VHL-hypoxia inducible factor (HIF) pathway has provided the foundation for the development of several agents targeting this pathway, such as sunitinib, sorafenib, and temsirolimus. Hereditary papillary renal carcinoma (HPRC) is a hereditary renal cancer syndrome in which affected individuals are at risk for the development of bilateral, multifocal, type 1 papillary renal cell carcinoma. The genetic defect underlying HPRC is MET, the cell surface receptor for hepatocyte growth factor. Mutations of MET also have been identified in a subset of tumors from patients with sporadic type 1 papillary renal cell carcinoma (RCC). Clinical trials targeting the MET pathway are currently underway in patients with HPRC and in patients with sporadic (nonhereditary) papillary kidney cancer. The BHD gene (also known as folliculin or FLCN) is the gene for Birt-Hogg-Dube syndrome, an autosomal-dominant genodermatosis associated with a hereditary form of chromophobe and oncocytic, hybrid RCC. Preclinical studies are underway targeting the BHD gene pathway in preparation for clinical trials in Birt-Hogg-Dube and sporadic chromophobe RCC. Patients with hereditary leiomyomatosis RCC (HLRCC) are at risk for developing cutaneous and uterine leiomyomas and a very aggressive type of RCC. HLRCC is characterized by germline mutation of the Krebs cycle enzyme, fumarate hydratase (FH). Studies of the tricarboxylic acid cycle and the VHL-HIF pathways have provided the foundation for therapeutic approaches in patients with HLRCC-associated kidney cancer as well as other hereditary and sporadic forms of RCC.

Incidence of cutaneous sebaceous carcinoma and risk of associated neoplasms: insight into Muir-Torre syndrome

BACKGROUND

Sebaceous tumors of the skin occurring in association with an internal malignancy characterize Muir-Torre syndrome (MTS), a variant of hereditary nonpolyposis colon cancer (Lynch syndrome). To the authors' knowledge, only limited information exists regarding incidence patterns of sebaceous carcinoma (SC), and no prior study has quantified risks of associated cancers.

METHODS

The authors calculated cutaneous SC incidence rates (IRs) and IR ratios in 9 US Surveillance, Epidemiology, and End Results program registries (1973-2003). Indirectly standardized incidence ratios and 95% confidence intervals (95% CIs) were calculated for subsequent cancers among 2-month survivors of SC and for subsequent SC after other primary cancers.

RESULTS

Among 664 cases of cutaneous SC, nearly 90% were diagnosed among whites (IR, 0.11 per 100,000 person-years), with significantly lower IR noted among blacks (IR, 0.04). Whereas eyelid SC IRs demonstrated no sex differences and stabilized in recent years, IRs of noneyelid SC predominated in men and rose steadily over time. Survivors of SC had a 43% (95% CI, 15%-76%) increased risk of subsequent cancer, and risk of SC was elevated by 52% (95% CI, 24%-84%) among survivors of other cancers. Whether before or after SC, the significant excesses of other primary cancers were limited to noneyelid SC. Patterns suggestive of genetic predisposition included >20-fold risks for early-onset (diagnosed in patients aged <50 years) SC associated with colon, pancreatic, ovarian, or uterine corpus cancers, whereas late-onset SC (diagnosed in patients aged > or =50 years) predisposed to ureter cancer.

CONCLUSIONS

This population-based study of cutaneous SC revealed an association with a spectrum of early-onset cancers consistent with MTS. Etiologic heterogeneity was suggested by differences between eyelid and noneyelid SC in incidence patterns and associated cancer risks.

Association of germline mutations in the fumarate hydratase gene and uterine fibroids in women with hereditary leiomyomatosis and renal cell cancer

OBJECTIVE

To investigate the risk of uterine fibroids and other reproductive risk factors in women with hereditary leiomyomatosis and renal cell cancer (HLRCC).

DESIGN

Case-control study.

SETTING

National Institutes of Health, Rockville, Maryland. Patients A family-based case-control study was conducted between July 1, 2004, and June 30, 2006, including 105 women from families with HLRCC ascertained throughout North America. A telephone interview was conducted with all participants using a standardized questionnaire that elicited information about their menstrual, pregnancy, uterine fibroid, and hormonal contraceptive use history. Diagnosis of uterine fibroids was confirmed by pathologic diagnosis and by medical record review. DNA was extracted from blood samples and was screened for germline mutations in the fumarate hydratase (FH) gene.

MAIN OUTCOME MEASURES

FH germline mutation status, presence of uterine fibroids, age at diagnosis, and symptoms and treatment of uterine fibroids.

RESULTS

Of 105 women, 77 reported a history of uterine fibroids. Regardless of uterine fibroid status, 75 of 105 women had a germline mutation in FH (FH(mut) positive). The risk of uterine fibroids in FH(mut)-positive women was statistically significantly increased compared with that in FH(mut)-negative women (odds ratio [OR], 7.6; 95% confidence interval [CI], 2.9-20.0), as it was among women clinically affected with HLRCC compared with those clinically unaffected with HLRCC (8.6; 3.1-24.0). The median age at uterine fibroid diagnosis for FH(mut)-positive women (28 years) was significantly younger than that for FH(mut)-negative women (38 years) (P =.03). Women with a germline mutation in FH or clinically affected with HLRCC reported younger age at menarche (P < .004) compared with FH(mut)-negative women (P = .02) or women who were clinically unaffected with HLRCC. Women with HLRCC were more likely to have had treatment for uterine fibroids (OR, 4.6; 95% CI, 1.4-15.8), including hysterectomy (P =.02) at an earlier age compared with women who were clinically unaffected with HLRCC.

CONCLUSIONS

This study provides the first evidence (to our knowledge) that women with germline mutations in FH and with clinical HLRCC have an increased risk of developing uterine fibroids. These women also have a younger age at uterine fibroid diagnosis and are more likely to have treatment for uterine fibroids at a younger age than women without HLRCC in their families.

Novel transglutaminase-1 mutations and genotype-phenotype investigations of 104 patients with autosomal recessive congenital ichthyosis in the USA

BACKGROUND

Autosomal recessive congenital ichthyosis (ARCI) is a rare hereditary disorder of cornification. Mutations in the transglutaminase-1 (TGM1) gene, which encodes for the epidermal enzyme transglutaminase-1 (TGase-1), are one of the causes of ARCI.

METHODS

The TGM1 mutation spectrum was characterised and genotype-phenotype correlations investigated in 104 patients with ARCI ascertained through the National Registry for Ichthyosis and Related Disorders in the USA. Methods: Germline mutations in TGM1 were identified in 55% (57/104) of patients with ARCI. Arginine residues in TGase-1 were mutated in 39% (22/57) of patients overall and 54% (20/37) of those with missense mutations. In total, 55% (12/22) of missense mutations were within CpG dinucleotides and 92% (11/12) of these mutations were C-->T or G-->A transitions. The genotype-phenotype investigation found that ARCI with TGM1 mutations was significantly associated with presence of collodion membrane at birth (p = 0.006), ectropion (p = 0.001), plate-like scales (p = 0.005) and alopecia (p = 0.001). Patients who had at least one mutation predicted to truncate TGase-1 were more likely to have more severe hypohidrosis (p = 0.001) and overheating (p = 0.0007) at onset of symptoms than were those with exclusively TGM1 missense mutations. A logistic model was developed, which predicted that individuals with collodion membrane, alopecia and/or eye problems are about four times more likely to have TGM1 mutations than patients without these findings.

CONCLUSION

This is the largest investigation of patients with ARCI to date. It expands the TGM1 mutation spectrum and confirms that despite genetic and phenotypic heterogeneity in ARCI, TGM1 is the main causative gene for this disorder. The high frequency of mutated arginine codons in TGM1 may be due to the deamination of CpG dinucleotides.

Improved identification of von Hippel-Lindau gene alterations in clear cell renal tumors

PURPOSE

To provide a comprehensive, thorough analysis of somatic mutation and promoter hypermethylation of the von Hippel-Lindau (VHL) gene in the cancer genome, unique to clear cell renal cancer (ccRCC). Identify relationships between the prevalence of VHL gene alterations and alteration subtypes with patient and tumor characteristics.

EXPERIMENTAL DESIGN

As part of a large kidney cancer case-control study conducted in Central Europe, we analyzed VHL mutations and promoter methylation in 205 well-characterized, histologically confirmed patient tumor biopsies using a combination of sensitive, high-throughput methods (endonuclease scanning and Sanger sequencing) and analysis of 11 CpG sites in the VHL promoter.

RESULTS

We identified mutations in 82.4% of cases, the highest VHL gene mutation prevalence reported to date. Analysis of 11 VHL promoter CpG sites revealed that 8.3% of tumors were hypermethylated and all were mutation negative. In total, 91% of ccRCCs exhibited alteration of the gene through genetic or epigenetic mechanisms. Analysis of patient and tumor characteristics revealed that certain mutation subtypes were significantly associated with Fuhrman nuclear grade, metastasis, node positivity, and self-reported family history of RCC.

CONCLUSION

Detection of VHL gene alterations using these accurate, sensitive, and practical methods provides evidence that the vast majority of histologically confirmed ccRCC tumors possess genetic or epigenetic alteration of the VHL gene and support the hypothesis that VHL alteration is an early event in ccRCC carcinogenesis. These findings also indicate that VHL molecular subtypes can provide a sensitive marker of tumor heterogeneity among histologically similar ccRCC cases for etiologic, prognostic, and translational studies.

Autoinflammatory diseases: clinical and genetic advances

We conducted a literature review to investigate the recent advances in genetics, molecular biology, clinical manifestations, and therapy of 7 inherited diseases that are characterized by seemingly unprovoked inflammation. These autoinflammatory diseases include familial Mediterranean fever; tumor necrosis factor receptor-associated periodic syndrome; hyperimmunoglobulinemia D with periodic fever syndrome; pyogenic arthritis, pyoderma gangrenosum, and acne syndrome; and the 3 cryopyrinopathies: neonatal-onset multisystem inflammatory disease/chronic infantile neurologic cutaneous and arthropathy syndrome, familial cold autoinflammatory syndrome, and Muckle-Wells syndrome. Recent identification of the susceptibility genes for autoinflammatory diseases has broadened the clinical spectrum as well as the molecular basis of these diseases. The cryopyrinopathies represent a continuum of diseases associated with mutations in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene that encodes cryopyrin. Cryopyrin and pyrin (protein mutated in familial Mediterranean fever) belong to the family of PYRIN domain-containing proteins. Pyogenic arthritis, pyoderma gangrenosum, and acne syndrome is associated with mutations in the gene that encodes for CD2-binding protein 1 (CD2BP1), which binds pyrin. Recent studies have shown that activation of the interleukin 1beta pathway is a common mechanism in the pathogenesis of autoinflammatory diseases, further unifying these diseases. Recent advances in genetics and molecular biology have advanced our understanding of the pathogenesis of autoinflammatory diseases. Understanding autoinflammatory diseases will further our knowledge of cutaneous as well as systemic inflammation. Anakinra, a recombinant human interleukin 1 receptor antagonist, is a promising new biologic agent for the treatment of cryopyrinopathies as well other autoinflammatory diseases, such as tumor necrosis factor receptor-associated periodic syndrome and hyperimmunoglobulinemia D with periodic fever syndrome.

BHD mutations, clinical and molecular genetic investigations of Birt-Hogg-Dubé syndrome: a new series of 50 families and a review of published reports

BACKGROUND

Birt-Hogg-Dubé syndrome (BHDS) (MIM 135150) is an autosomal dominant predisposition to the development of follicular hamartomas (fibrofolliculomas), lung cysts, spontaneous pneumothorax, and kidney neoplasms. Germline mutations in BHD are associated with the susceptibility for BHDS. We previously described 51 BHDS families with BHD germline mutations.

OBJECTIVE

To characterise the BHD mutation spectrum, novel mutations and new clinical features of one previously reported and 50 new families with BHDS.

METHODS

Direct bidirectional DNA sequencing was used to screen for mutations in the BHD gene, and insertion and deletion mutations were confirmed by subcloning. We analysed evolutionary conservation of folliculin by comparing human against the orthologous sequences.

RESULTS

The BHD mutation detection rate was 88% (51/58). Of the 23 different germline mutations identified, 13 were novel consisting of: four splice site, three deletions, two insertions, two nonsense, one deletion/insertion, and one missense mutation. We report the first germline missense mutation in BHD c.1978A>G (K508R) in a patient who presented with bilateral multifocal renal oncocytomas. This mutation occurs in a highly conserved amino acid in folliculin. 10% (5/51) of the families had individuals without histologically confirmed fibrofolliculomas. Of 44 families ascertained on the basis of skin lesions, 18 (41%) had kidney tumours. Patients with a germline BHD mutation and family history of kidney cancer had a statistically significantly increased probability of developing renal tumours compared to patients without a positive family history (p = 0.0032). Similarly, patients with a BHD germline mutation and family history of spontaneous pneumothorax had a significantly increased greater probability of having spontaneous pneumothorax than BHDS patients without a family history of spontaneous pneumothorax (p = 0.011). A comprehensive review of published reports of cases with BHD germline mutation is discussed.

CONCLUSION

BHDS is characterised by a spectrum of mutations, and clinical heterogeneity both among and within families.

Family history and the risk of kidney cancer: a multicenter case-control study in Central Europe

An elevated familial relative risk may indicate either an important genetic component in etiology or shared environmental exposures within the family. Incidence rates of kidney cancer are particularly high in Central Europe, although no data were available on the familial aggregation or genetic background of kidney cancer in this region. We have, therefore, investigated the role of family history in first-degree relatives in a large multicenter case-control study in Central Europe. A total number of 1,097 cases of kidney cancer and 1,555 controls were recruited from 2000 to 2003 from seven centers in Czech Republic, Poland, Romania, and Russia. The risk of kidney cancer increased with the increasing number of relatives with history of any cancer [odds ratio (OR), 1.15; 95% confidence interval (95% CI), 1.00-1.31 per affected relative], and this association seemed to be more prominent among subjects with young onset (OR, 1.55; 95% CI, 1.09-2.20 per affected relative). Overall, the OR was 1.40 (95% CI, 0.71- 2.76) for the subjects who had at least one first-degree relative with kidney cancer after adjusting for tobacco smoking, body mass index, and medical history of hypertension, and this association was most apparent among subjects with affected siblings (OR, 4.09; 95% CI, 1.09-15.4). Based on the relative risk to siblings in our study population, we estimated that 80% of the kidney cancer cases are likely to occur in 20% of the population with the highest genetic risk, which indicate the importance of further investigation of genetic factors in cancer prevention for kidney cancer.

Abnormal microRNA-16 locus with synteny to human 13q14 linked to CLL in NZB mice

New Zealand black (NZB) mice with autoimmune and B lymphoproliferative disease (B-LPD) are a model for human chronic lymphocytic leukemia (CLL). A genomewide linkage scan of the NZB loci associated with lymphoma was conducted in F1 backcrosses of NZB and a control strain, DBA/2. Of 202 mice phenotyped for the presence or absence of LPD, surface maker expression, DNA content, and microsatellite polymorphisms, 74 had disease. The CD5(+), IgM(+), B220(dim), hyperdiploid LPD was linked to 3 loci on chromosomes 14, 18, and 19 that are distinct from previously identified autoimmunity-associated loci. The region of synteny with mouse D14mit160 is the human 13q14 region, associated with human CLL, containing microRNAs mir-15a16-1. DNA sequencing of multiple NZB tissues identified a point mutation in the 3' flanking sequence of the identical microRNA, mir-16-1, and this mutation was not present in other strains, including the nearest neighbor, NZW. Levels of miR-16 were decreased in NZB lymphoid tissue. Exogenous miR-16 delivered to an NZB malignant B-1 cell line resulted in cell-cycle alterations and increased apoptosis. Linkage of the mir-15a/16-1 complex and the development of B-LPD in this spontaneous mouse model suggest that the altered expression of the mir-15a/16-1 is the molecular lesion in CLL.

Lung cysts, spontaneous pneumothorax, and genetic associations in 89 families with Birt-Hogg-Dubé syndrome

RATIONALE

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal, dominantly inherited genodermatosis that predisposes to fibrofolliculomas, kidney neoplasms, lung cysts, and spontaneous pneumothorax.

OBJECTIVES

We evaluated 198 patients from 89 families with BHDS to characterize the risk factors for pneumothorax and genotype-pulmonary associations.

METHODS

Helical computed tomography scans of the chest were used to screen for pulmonary abnormalities. BHD mutation data were used for genotype-pulmonary associations. We examined the relationship of pneumothorax with categorical parameters (sex, smoking history, and lung cysts) and continuous parameters (number of cysts, lung cyst volume, and largest cyst diameter and volume). Logistic regression analyses were used to identify the risk factors associated with pneumothorax.

MEASUREMENTS AND MAIN RESULTS

Twenty-four percent (48/198) of patients with BHDS had a history of pneumothorax. The presence of lung cysts was significantly associated with pneumothorax (p = 0.006). Total lung cyst volume, largest cyst diameter and volume, and every parameter related to the number of lung cysts were significantly associated (p < 0.0001) with pneumothorax. A logistic regression analysis showed that only the total number of cysts in the right parenchymal lower lobe and the total number of cysts located on the pleural surface in the right middle lobe were needed to classify a patient as to whether or not he or she was likely to have a pneumothorax. Exon location of the BHD mutation was associated with the numbers of cysts (p = 0.0002).

CONCLUSIONS

This study indicates that patients with BHDS have a significant association between lung cysts and spontaneous pneumothorax.

Incidence patterns of soft tissue sarcomas, regardless of primary site, in the surveillance, epidemiology and end results program, 1978-2001: An analysis of 26,758 cases

Soft tissue sarcomas (STS) are a heterogeneous group of uncommon tumors that show a broad range of differentiation that may reflect etiologic distinction. Routine tabulations of STS are not morphology-specific. Further, the lack of inclusion of sarcomas arising in all organs in most standard evaluations underestimates the true rates. We analyzed the 1978-2001 Surveillance, Epidemiology and End Results program incidence rates of STS regardless of primary site, except bones and joints, using the 2002 criteria of the WHO classification. There were 26,758 cases available for analysis. Leiomyosarcomas accounted for 23.9%, malignant fibrous histiocytomas 17.1%, liposarcomas 11.5%, dermatofibrosarcomas 10.5%, rhabdomyosarcomas 4.6% and angiosarcomas 4.1%. Almost half (47.9%) of the sarcomas arose in the soft tissues, 14.0% in the skin and 7.0% in the uterus. Overall, incidence rates were highest among black women (6.26/100,000 woman-years) and the lowest among white women (4.60/100,000). Age-adjusted rates increased at 1.2% and 0.8% per year among white males and females, respectively, both trends statistically significant, while rates among blacks declined slightly. About 40% of leiomyosarcomas among women were uterine in origin, with a black/white rate ratio of 1.7. This rate ratio increased to 2.0 when we accounted for the lower prevalence of intact uteri among black compared to white women. Total STS rates rose exponentially with age. Rates for both uterine leiomyosarcoma and dermatofibrosarcoma increased rapidly during the childbearing years, peaking at about age 40 and 50, respectively. Incidence patterns of STS varied markedly by histologic type, supporting the notion that these tumors may be etiologically distinct.

Identification of a novel chromosome region, 13q21.33-q22.2, for susceptibility genes in familial chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most prevalent form of leukemia in adults in western countries. A genome scan of CLL-prone families revealed a lod score of one in band 13q22.1. To investigate this finding, we selected 6 CLL families consisting of 63 individuals (CLL affected, n = 19; unaffected, n = 44) for fine mapping of a 23-megabase region in 13q14.2-q22.2. Interphase fluorescence in situ hybridization (FISH) revealed 13q14 deletion in 85% (11/13) of CLL patients. Four CLL families shared a 3.68-Mb minimal region in 13q21.33-q22.2. Two asymptomatic siblings who shared the 13q21.33-q22.2 at-risk haplotype exhibited CD5+ monoclonal B-cell lymphocytosis (MBL) on flow cytometry. One of these individuals also had a 13q14 deletion by FISH. These 2 individuals with MBL shared the at-risk haplotype with their CLL-affected relatives, providing further evidence of the relationship between CLL and MBL, as well as of the biologic significance of this novel region. Using direct DNA sequencing analysis, we screened 13 genes for mutations, but no frameshift or nonsense mutations were detected. Our studies revealed that 11 of the 13 genes in the candidate region were expressed in immune tissues, supporting their functional relevance in investigations of familial CLL. In conclusion, we identified a novel candidate region that may predispose to familial CLL.

High-density mapping and follow-up studies on chromosomal regions 1, 3, 6, 12, 13 and 17 in 28 families with chronic lymphocytic leukaemia

A subset of chronic lymphocytic leukaemia (CLL) shows familial aggregation. Studies show an increased risk for CLL and other lymphoproliferative disease among first-degree relatives of affected individuals. A genome-wide scan of 18 CLL families in 2003 detected LOD or non-parametric linkage scores > or = 1.0 on chromosomes 1, 3, 6, 12, 13 and 17. Follow-up study with 28 families showed no evidence of linkage at 1p22.1-p21.2, 3q22.1, 3q26.2, 6q22.31-q23.2, 12q24.23, 14q32.13, 17p13.3. Chromosome 13q21.33 remains a region of interest with a P-value of 0.013 (marker D13S1291) and warrants additional molecular investigation as a susceptibility region for CLL.

Fumarate hydratase enzyme activity in lymphoblastoid cells and fibroblasts of individuals in families with hereditary leiomyomatosis and renal cell cancer

BACKGROUND

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is the autosomal dominant heritable syndrome with predisposition to development of renal cell carcinoma and smooth muscle tumours of the skin and uterus.

OBJECTIVE

To measure the fumarate hydratase (FH) enzyme activity in lymphoblastoid cell lines and fibroblast cell lines of individuals with HLRCC and other familial renal cancer syndromes.

METHODS

FH enzyme activity was determined in the whole cell, cytosolic, and mitochondrial fractions in 50 lymphoblastoid and 16 fibroblast cell lines including cell lines from individuals with HLRCC with 16 different mutations.

RESULTS

Lymphoblastoid cell lines (n = 20) and fibroblast cell lines (n = 11) from individuals with HLRCC had lower FH enzyme activity than cells from normal controls (p<0.05). The enzyme activity in lymphoblastoid cell lines from three individuals with mutations in R190 was not significantly different from individuals with other missense mutations. The cytosolic and mitochondrial FH activity of cell lines from individuals with HLRCC was reduced compared with those from control cell lines (p<0.05). There was no significant difference in enzyme activity between control cell lines (n = 4) and cell lines from affected individuals with other hereditary renal cancer syndromes (n = 22).

CONCLUSIONS

FH enzyme activity testing provides a useful diagnostic method for confirmation of clinical diagnosis and screening of at-risk family members.

Novel mutations in FH and expansion of the spectrum of phenotypes expressed in families with hereditary leiomyomatosis and renal cell cancer

BACKGROUND

Hereditary leiomyomatosis and renal cell cancer (HLRCC; OMIM 605839) is the predisposition to develop smooth muscle tumours of the skin and uterus and/or renal cancer and is associated with mutations in the fumarate hydratase gene (FH). Here we characterise the clinical and genetic features of 21 new families and present the first report of two African-American families with HLRCC.

METHODS

Using direct sequencing analysis we identified FH germline mutations in 100% (21/21) of new families with HLRCC.

RESULTS

We identified 14 germline FH mutations (10 missense, one insertion, two nonsense, and one splice site) located along the entire length of the coding region. Nine of these were novel, with six missense (L89S, R117G, R190C, A342D, S376P, Q396P), one nonsense (S102X), one insertion (111insA), and one splice site (138+1G>C) mutation. Four unrelated families had the R58X mutation and five unrelated families the R190H mutation. Of families with HLRCC, 62% (13/21) had renal cancer and 76% (16/21) cutaneous leiomyomas. Of women FH mutation carriers from 16 families, 100% (22/22) had uterine fibroids. Our study shows that expression of cutaneous manifestations in HLRCC ranges from absent to mild to severe cutaneous leiomyomas. FH mutations were associated with a spectrum of renal tumours. No genotype-phenotype correlations were identified.

CONCLUSIONS

In combination with our previous report, we identify 31 different germline FH mutations in 56 families with HLRCC (20 missense, eight frameshifts, two nonsense, and one splice site). Our FH mutation detection rate is 93% (52/56) in families suspected of HLRCC.

Germline BHD-mutation spectrum and phenotype analysis of a large cohort of families with Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé syndrome (BHD), a genodermatosis characterized by multiple hamartomas of the hair follicle (fibrofolliculoma), predisposes individuals to an increased risk of developing renal neoplasms and spontaneous pneumothorax. Previously, we localized the BHD locus (also known as FLCN) to chromosome 17p11.2 by linkage analysis and subsequently identified germline mutations in a novel gene in probands from eight of the nine families with BHD in our screening panel. Affected members of five of the families inherited an insertion/deletion of a cytosine in a C8 tract in exon 11. This mutation was also identified by exon 11 screening in probands from 22 of 52 additional families with BHD and therefore represents a hypermutable "hotspot" for mutation in BHD. Here, we screened the remaining 30 families from this large BHD cohort by direct sequence analysis and identified germline BHD mutations in 84% (51/61) of all families with BHD recruited to our study. Mutations were located along the entire length of the coding region, including 16 insertion/deletion, 3 nonsense, and 3 splice-site mutations. The majority of BHD mutations were predicted to truncate the BHD protein, folliculin. Among patients with a mutation in the exon 11 hotspot, significantly fewer renal tumors were observed in patients with the C-deletion than those with the C-insertion mutation. Coding-sequence mutations were not found, however, in probands from two large families with BHD whose affected members shared their family's BHD-affected haplotype. Of the 53 families with BHD whose members inherited either a germline mutation or the affected haplotype, 24 (45%) had at least one member with renal neoplasms. Three families classified with familial renal oncocytoma were identified with BHD mutations, which represents the first disease gene associated with this rare form of renal neoplasm. This study expands the BHD-mutation spectrum and evaluates genotype-phenotype correlations among families with BHD.

Mutations in the fumarate hydratase gene cause hereditary leiomyomatosis and renal cell cancer in families in North America

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant disorder characterized by smooth-muscle tumors of the skin and uterus and/or renal cancer. Although the identification of germline mutations in the fumarate hydratase (FH) gene in European families supports it as the susceptibility gene for HLRCC, its role in families in North America has not been studied. We screened for germline mutations in FH in 35 families with cutaneous leiomyomas. Sequence analysis revealed mutations in FH in 31 families (89%). Twenty different mutations in FH were identified, of which 18 were novel. Of these 20 mutations, 2 were insertions, 5 were small deletions that caused frameshifts leading to premature truncation of the protein, and 13 were missense mutations. Eleven unrelated families shared a common mutation: R190H. Eighty-one individuals (47 women and 34 men) had cutaneous leiomyomas. Ninety-eight percent (46/47) of women with cutaneous leiomyomas also had uterine leiomyomas. Eighty-nine percent (41/46) of women with cutaneous and uterine leiomyomas had a total hysterectomy, 44% at age < or =30 years. We identified 13 individuals in 5 families with unilateral and solitary renal tumors. Seven individuals from four families had papillary type II renal cell carcinoma, and another individual from one of these families had collecting duct carcinoma of the kidney. The present study shows that mutations in FH are associated with HLRCC in North America. HLRCC is associated with clinically significant uterine fibroids and aggressive renal tumors. The present study also expands the histologic spectrum of renal tumors and FH mutations associated with HLRCC.

Gamma-delta T-cell phenotype is associated with significantly decreased survival in cutaneous T-cell lymphoma

The importance of alpha beta versus gamma delta T-cell subset antigen expression in the classification of peripheral T-cell lymphomas is still unclear. The objective of this study was to investigate the prognostic value of T-cell receptor-delta 1 (TCR delta 1) expression in primary cutaneous T-cell lymphomas. TCR delta 1 cellular expression was assessed in skin biopsy specimens of 104 individuals with cutaneous T-cell lymphoma by immunohistochemistry. Both univariate (Kaplan-Meier) and multivariate (Cox regression) analyses were conducted to determine which variables (T-cell subtype, hemophagocytosis, histologic profile, age, sex, and adenopathy) were significantly associated with survival. Univariate analysis indicated that there was a statistically significant difference in survival between the patients with alpha beta cutaneous T-cell lymphoma and patients with gamma delta cutaneous T-cell lymphoma (P <.0001). There was also a statistically significant decrease in survival among patients who had subcutaneous involvement compared with patients who had epidermotropic and/or dermal involvement (P <.0001). Cox model analysis indicated that TCR delta 1 expression was the factor that was most closely associated with decreased survival (P <.0001). Among those patients with cutaneous gamma delta T-cell lymphoma (n = 33), there was a trend for decreased survival for patients who had histologic evidence of subcutaneous fat involvement in comparison with patients who had epidermotropic or dermal patterns of infiltration (P =.067). No other prognostic factors were identified as having a notable association with outcome in this subgroup. TCR delta 1 expression in primary cutaneous lymphomas is an independent prognostic factor associated with decreased survival.

Topical cidofovir for the treatment of dermatologic conditions: verruca, condyloma, intraepithelial neoplasia, herpes simplex and its potential use in smallpox

Cidofovir is a new antiviral drug that has a broad spectrum of activity against several DNA viruses. Many of the disorders caused by these viruses do not have satisfactory therapy, and given the efficacy of this agent in treating many of these conditions, it holds great promise. It is hoped that ongoing studies will confirm the initial anecdotal reports regarding its therapeutic efficacy and lack of systemic side effects. It is also hoped that the cost to formulate and use cidofovir topically will eventually decrease to a level that will allow more widespread use of this drug.

Mutations in a novel gene lead to kidney tumors, lung wall defects, and benign tumors of the hair follicle in patients with the Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé (BHD) syndrome is a rare inherited genodermatosis characterized by hair follicle hamartomas, kidney tumors, and spontaneous pneumothorax. Recombination mapping in BHD families delineated the susceptibility locus to 700 kb on chromosome 17p11.2. Protein-truncating mutations were identified in a novel candidate gene in a panel of BHD families, with a 44% frequency of insertion/deletion mutations within a hypermutable C(8) tract. Tissue expression of the 3.8 kb transcript was widespread, including kidney, lung, and skin. The full-length BHD sequence predicted a novel protein, folliculin, that was highly conserved across species. Discovery of disease-causing mutations in BHD, a novel kidney cancer gene associated with renal oncocytoma or chromophobe renal cancer, will contribute to understanding the role of folliculin in pathways common to skin, lung, and kidney development.

Hermansky-Pudlak syndrome type 3 in Ashkenazi Jews and other non-Puerto Rican patients with hypopigmentation and platelet storage-pool deficiency

Hermansky-Pudlak syndrome (HPS), consisting of oculocutaneous albinism and a bleeding diathesis due to the absence of platelet dense granules, displays extensive locus heterogeneity. HPS1 mutations cause HPS-1 disease, and ADTB3A mutations cause HPS-2 disease, which is known to involve abnormal intracellular vesicle formation. A third HPS-causing gene, HPS3, was recently identified on the basis of homozygosity mapping of a genetic isolate of HPS in central Puerto Rico. We now describe the clinical and molecular characteristics of eight patients with HPS-3 who are of non-Puerto Rican heritage. Five are Ashkenazi Jews; three of these are homozygous for a 1303+1G-->A splice-site mutation that causes skipping of exon 5, deleting an RsaI restriction site and decreasing the amounts of mRNA found on northern blotting. The other two are heterozygous for the 1303+1G-->A mutation and for either an 1831+2T-->G or a 2621-2A-->G splicing mutation. Of 235 anonymous Ashkenazi Jewish DNA samples, one was heterozygous for the 1303+1G-->A mutation. One seven-year-old boy of German/Swiss extraction was compound heterozygous for a 2729+1G-->C mutation, causing skipping of exon 14, and resulting in a C1329T missense (R396W), with decreased mRNA production. A 15-year-old Irish/English boy was heterozygous for an 89-bp insertion between exons 16 and 17 resulting from abnormal splicing; his fibroblast HPS3 mRNA is normal in amount but is increased in size. A 12-year-old girl of Puerto Rican and Italian background has the 3,904-bp founder deletion from central Puerto Rico on one allele. All eight patients have mild symptoms of HPS; two Jewish patients had received the diagnosis of ocular, rather than oculocutaneous, albinism. These findings expand the molecular diagnosis of HPS, provide a screening method for a mutation common among Jews, and suggest that other patients with mild hypopigmentation and decreased vision should be examined for HPS.

Birt-Hogg-Dubé syndrome, a genodermatosis associated with spontaneous pneumothorax and kidney neoplasia, maps to chromosome 17p11.2

Birt-Hogg-Dubé syndrome (BHD), an inherited autosomal genodermatosis characterized by benign tumors of the hair follicle, has been associated with renal neoplasia, lung cysts, and spontaneous pneumothorax. To identify the BHD locus, we recruited families with cutaneous lesions and associated phenotypic features of the BHD syndrome. We performed a genomewide scan in one large kindred with BHD and, by linkage analysis, localized the gene locus to the pericentromeric region of chromosome 17p, with a LOD score of 4.98 at D17S740 (recombination fraction 0). Two-point linkage analysis of eight additional families with BHD produced a maximum LOD score of 16.06 at D17S2196. Haplotype analysis identified critical recombinants and defined the minimal region of nonrecombination as being within a <4-cM distance between D17S1857 and D17S805. One additional family, which had histologically proved fibrofolliculomas, did not show evidence of linkage to chromosome 17p, suggesting genetic heterogeneity for BHD. The BHD locus lies within chromosomal band 17p11.2, a genomic region that, because of the presence of low-copy-number repeat elements, is unstable and that is associated with a number of diseases. Identification of the gene for BHD may reveal a new genetic locus responsible for renal neoplasia and for lung and hair-follicle developmental defects.

Mutation of a new gene causes a unique form of Hermansky-Pudlak syndrome in a genetic isolate of central Puerto Rico

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism and a storage pool deficiency due to an absence of platelet dense bodies. Lysosomal ceroid lipofuscinosis, pulmonary fibrosis and granulomatous colitis are occasional manifestations of the disease. HPS occurs with a frequency of one in 1800 in north-west Puerto Rico due to a founder effect. Several non-Puerto Rican patients also have mutations in HPS1, which produces a protein of unknown function. Another gene, ADTB3A, causes HPS in the pearl mouse and in two brothers with HPS-2 (refs. 11,12). ADTB3A encodes a coat protein involved in vesicle formation, implicating HPS as a disorder of membrane trafficking. We sought to identify other HPS-causing genes. Using homozygosity mapping on pooled DNA of 6 families from central Puerto Rico, we localized a new HPS susceptibility gene to a 1.6-cM interval on chromosome 3q24. The gene, HPS3, has 17 exons, and a putative 113.7-kD product expected to reveal how new vesicles form in specialized cells. The homozygous, disease-causing mutation is a large deletion and represents the second example of a founder mutation causing HPS on the small island of Puerto Rico. We also present an allele-specific assay for diagnosing individuals heterozygous or homozygous for this mutation.

Tumor necrosis factor receptor-associated periodic syndrome: a novel syndrome with cutaneous manifestations

BACKGROUND

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an inflammatory disorder characterized by prolonged episodes of periodic fever and localized inflammation and dominantly inherited mutations in TNFRSF1A, the gene encoding the 55-kDa tumor necrosis factor receptor. To our knowledge, the cutaneous pathologic characteristics of TRAPS have not been described previously.

OBJECTIVES

To characterize the dermatologic manifestations of TRAPS by clinical, microscopic, and molecular methods, and to investigate its immunophenotype.

DESIGN, SETTING, AND PATIENTS

At the National Institutes of Health Clinical Center, Bethesda, Md, a tertiary care referral center, 25 patients with a clinical and molecular diagnosis of TRAPS were evaluated clinically and 10 biopsy specimens of lesional skin were examined by light microscopy and immunohistochemistry. Patients were screened for mutations in TNFRSF1A, the gene coding for the p55 tumor necrosis factor receptor.

MAIN OUTCOME MEASURES

Clinical, light microscopic, and immunohistochemical features.

RESULTS

The skin eruption usually lasted 4 to 21 days (mean, 13 days). Of 25 patients, 21 (84%) presented with migratory erythematous macules and patches and 10 (40%) had edematous dermal plaques. Conjunctivitis, characterized by pain and redness and/or periorbital edema, was present in 11 patients (44%). Most patients had their first skin eruption during the first 2 years of life. All patients had fever associated with the skin eruption. Most patients had associated abdominal pain (22 [88%]) and myalgia (20 [80%]). Other symptoms included arthralgia (13 [52%]), pleuritic chest pain (10 [40%]), and headache (17 [68%]). Microscopic examination of 10 biopsy specimens of lesional skin showed a superficial and deep perivascular and interstitial infiltrate of lymphocytes and monocytes. None of the biopsy specimens showed multinucleated macrophages or granulomatous or leukocytoclastic vasculitis. The results of immunohistochemistry showed a perivascular infiltrate of CD3+, CD4+, CD8+, CD68+, CD79a-, and CD20- cells. All the mutations were missense mutations in exons 2 through 4 of TNFRSF1A, directly affecting the extracellular domain of the protein.

CONCLUSIONS

TRAPS is characterized by a spectrum of dermatologic findings, including migratory patches, edematous plaques, periorbital edema, and/or conjunctivitis. TRAPS is characterized by a perivascular dermal infiltrate of lymphocytes and monocytes.

Detection of type 1 cytokines in discoid lupus erythematosus

BACKGROUND

Although multiple studies suggest a dysregulated T-cell cytokine production in systemic lupus erythematosus, the cytokine profile in discoid lupus erythematosus (DLE) lesions is unknown.

OBJECTIVES

To characterize the cytokine profile in DLE by immunohistochemical and molecular methods, and to investigate the role of cytokines in the pathogenesis of DLE.

DESIGN

Patients were evaluated clinically, and biopsy specimens of lesional skin were examined by light microscopy. Reverse transcriptase-polymerase chain reaction and immunohistochemical analysis were performed on 11 biopsy specimens. We investigated the presence of interleukin (IL) 2, interferon gamma (IFN-gamma), IL-4, tumor necrosis factor alpha, (TNF-alpha), and IL-1beta messenger RNA (mRNA) in 8 biopsy specimens of DLE and compared it with 3 biopsy specimens of normal skin.

SETTING

Academic referral research hospital.

PATIENTS

Eight consecutive patients with a clinical and histologic diagnosis of DLE.

RESULTS

Localized DLE was found in 7 patients and widespread in 1. During the 4 years of the investigation, none of the patients developed systemic lupus erythematosus. We found significantly elevated levels of IL-2 and IFN-gamma mRNA in all 8 biopsy specimens of DLE; in contrast, no transcripts of IL-2 or IFN-gamma were detected in 3 biopsy specimens of normal skin (P<.01). Similarly, elevated levels of TNF-alpha mRNA were detected in 8 DLE biopsy specimens, while no TNF-alpha mRNA was detected in 3 biopsy specimens of normal skin (P<.01). No IL-4 or IL-1 beta mRNA was detected in 8 biopsy specimens of DLE lesional skin and 3 biopsy specimens of normal patient skin. Immunohistochemical analysis showed increased staining for IL-2 and IFN-gamma receptors, while no detectable IL-4 receptor was found. No cytokine mRNA or cytokine receptor protein was detected in biopsy specimens of normal skin.

CONCLUSIONS

These findings suggest that DLE is associated with type 1 cytokines characterized by the expression of IL-2 and IFN-gamma. Type 1 cytokines may be critical for induction, development, and maintenance of DLE.

gamma delta T-cell lymphoma of the skin: a clinical, microscopic, and molecular study

BACKGROUND

Only a few cases of primary gamma delta cutaneous T-cell lymphoma (CTCL) have been reported. We encountered 3 cases of this rare condition.

OBJECTIVES

To characterize gamma delta CTCL by clinical, microscopic, and molecular methods and to investigate the role of Epstein-Barr virus (EBV) infection in its pathogenesis.

DESIGN

Patients were evaluated by clinical examination, and biopsy specimens of lesional skin were examined by light microscopy and immunohistochemistry. Polymerase chain reaction amplification for T-cell receptor gamma gene rearrangements and in situ hybridization for EBV were performed on 3 biopsy specimens.

SETTING

National Institutes of Health, a tertiary referral center.

PATIENTS

Individuals with a clinical and histologic diagnosis of primary gamma delta CTCL.

OUTCOME MEASURES

Clinical, light microscopic, and immunohistochemical features, and the presence of T-cell rearrangement and EBV RNA in biopsy specimens.

RESULTS

Patients exhibited multiple plaques, tumors, and/or subcutaneous nodules primarily distributed over the extremities. Individuals exhibited an aggressive clinical course with resistance to multiagent chemotherapy and radiation. Microscopic examination revealed epidermotropism in 2 cases, a dermal infiltrate in all 3 cases, and subcutaneous involvement in 1 case. Immunohistochemical studies showed the presence of CD3(+)TCR delta(+) in 3 patients, CD8(+)in 1, and CD4(+), CD20(+), CD56(+), and beta F1(+) in none. All 3 cases exhibited an activated cytotoxic T-cell phenotype positive for T-cell intracellular antigen 1, perforin, and granzyme B. A clonal T-cell receptor gamma chain gene rearrangement was detected in all 3 cases by polymerase chain reaction. In situ hybridization was negative for EBV sequences in all 3 cases.

CONCLUSION

gamma delta Cutaneous T-cell lymphomas are EBV-negative lymphomas that express a mature cytotoxic phenotype and have an aggressive clinical behavior. Arch Dermatol. 2000;136:1024-1032

Splice-site mutation in TGM1 in congenital recessive ichthyosis in American families: molecular, genetic, genealogic, and clinical studies

Lamellar ichthyosis (LI, OMIM no. 242300) is a severe autosomal recessive genodermatosis with an estimated prevalence of 1:200,000. LI represents one end of the spectrum of congenital recessive ichthyosis (CRI). Mutations in the gene for transglutaminase-1 (TGM1) are responsible for many cases of LI and occur throughout the coding sequence of the gene. Our analyses of patients with CRI revealed a common TGM1 mutation involving loss of the intron 5 splice acceptor site leading to alternative splicing of the message. We found families in which the splice acceptor site mutation was homozygous, and families where the patients were compound heterozygotes for the splice acceptor site mutation and another TGM1 mutation. A mutation at this same site occurs in the majority of Norwegian patients as a founder effect. In our ethnically diverse patient population, none of whom have known Norwegian ancestry, haplotype analysis of the TGM1 chromosomal region also suggested the existence of a founder effect. Comparison of the common haplotype in our data with the Norwegian data showed that 2/7 of our splice acceptor site mutation chromosomes had the full reported Norwegian haplotype, and the remaining five chromosomes exhibited recombination at the most distal marker studied. History, family origins, and haplotype analysis suggested that the mutation originally arose on a German background and was introduced into Norway around 800-1000 AD. We also found a limited correlation between genotype and phenotype in our study, with the four homozygous patients having less severe disease than many of the heterozygotes, and no patient with a splice acceptor site mutation having erythroderma or a congenital ichthyosiform erythroderma phenotype.

Granuloma annulare and human immunodeficiency virus infection

OBJECTIVES

To characterize human immunodeficiency virus (HIV)-associated granuloma annulare (GA) by clinical, microscopic, and molecular methods and to investigate the role of Epstein-Barr virus infection in the pathogenesis of GA.

DESIGN

Patients were evaluated clinically, and biopsy specimens of lesional skin were examined by light microscopy. Polymerase chain reaction and in situ hybridization for Epstein-Barr virus were performed on 4 and 12 biopsy specimens, respectively.

SETTING

Academic referral center.

PATIENTS

Thirty-four consecutive HIV-positive patients who have a clinical and histological diagnosis of GA.

OUTCOME MEASURES

Clinical distribution of lesions, light-microscopic features, and the presence of Epstein-Barr virus DNA and RNA in biopsy specimens.

RESULTS

Granuloma annulare was generalized in 20 patients and localized in 14. Twenty patients (59%) presented with acquired immunodeficiency syndrome. Unusual features were the presence of oral lesions in 1 patient, perforating lesions in 2 patients, and the coexistence of GA and Kaposi sarcoma in 1 biopsy specimen. Microscopic examination of 34 biopsy specimens showed a granulomatous pattern that was interstitial in 8, palisaded in 18, perforating in 2, and mixed interstitial and palisaded in 6. Special staining of all specimens was negative for organisms. Epstein-Barr virus infection was not detected by either polymerase chain reaction or in situ hybridization.

CONCLUSIONS

Generalized GA is the most common clinical pattern in HIV infection. Granuloma annulare associated with HIV can present at all stages of HIV infection, but it is slightly more common in patients with acquired immunodeficiency syndrome. Epstein-Barr virus is an unlikely causative agent of HIV-associated GA. Granuloma annulare may be a manifestation of increasing immune dysregulation.

Birt-Hogg-Dubé syndrome: a novel marker of kidney neoplasia

BACKGROUND

Birt-Hogg-Dubé syndrome (BHD) is a dominantly inherited predisposition for development of fibrofolliculomas, trichodiscomas, and acrochordons. Concurrent internal tumors, such as colonic polyps and renal carcinoma, have been described in patients with BHD.

OBJECTIVE

To evaluate kindreds with familial renal tumors for cutaneous manifestations of BHD.

DESIGN

One hundred fifty-two patients from 49 families underwent complete oral and skin examination. Skin lesions were identified by their clinical appearance, and the diagnosis was confirmed by results of histologic examination. Individuals underwent screening for familial renal neoplasms.

SETTING

A tertiary referral research hospital.

PATIENTS

Individuals with familial renal tumors and their asymptomatic at-risk relatives.

MAIN OUTCOME MEASURE

We determined whether any form of renal cancer is associated BHD.

RESULTS

We identified 3 extended kindreds in whom renal neoplasms and BHD appeared to segregate together. Two kindreds had renal oncocytomas and a third had a variant of papillary renal cell carcinoma. Thirteen patients exhibited BHD. Seven individuals, including a set of identical twins, had renal neoplasms and BHD. An additional 4 patients (3 deceased and not examined) in these families had renal neoplasms but not BHD. Birt-Hogg-Dubé syndrome without renal neoplasms was present in 6 individuals. Thirteen patients with fibrofolliculomas and trichodiscomas presented clinically with multiple smooth skin-colored to grayish-white papules located on the face, auricles, neck, and upper trunk. Oral papules were present in 9 of 28 and achrochordons in 11 of 28 patients. Features of BHD not previously appreciated included deforming lipomas in 5, collagenomas in 4, and pulmonary cysts in 4 of 28 patients. Families with BHD did not display germline mutations in the von Hippel-Lindau gene or in the tyrosine kinase domain of the MET proto-oncogene.

CONCLUSIONS

Birt-Hogg-Dubé syndrome may be associated with familial renal tumors. Birt-Hogg-Dubé and renal tumors segregate together in an autosomal dominant fashion. Patients with BHD and their relatives are at risk for development of renal tumors. Therefore, patients with BHD and their relatives should undergo abdominal computed tomography and renal ultrasound screening for renal tumors.