Col4a1 mutation generates vascular abnormalities correlated with neuronal damage in a mouse model of HANAC syndrome.

The HANAC syndrome is caused by mutations in the gene coding for collagen4a1, a major component of blood vessel basement membranes. Ocular symptoms include an increase in blood vessel tortuosity and occasional hemorrhages. To examine how vascular defects can affect neuronal function, we analyzed the retinal phenotype of a HANAC mouse model. Heterozygous mutant mice displayed both a thinning of the basement membrane in retinal blood vessels and in Bruch's membrane resulting in vascular leakage. Homozygous mice had additional vascular changes, including greater vessel coverage and tortuosity. This greater tortuosity was associated to higher expression levels of vascular endothelial growth factor (VEGF). These major changes to the blood vessels were correlated with photoreceptor dysfunction and degeneration. The neuronal damage was associated with reactive gliosis in astrocytes and Müller glial cells, and by the migration of microglial cells into the outer retina. This study illustrates how vascular changes can trigger neuronal degeneration in a new model of HANAC syndrome that can be used to further study dysfunctions of neurovascular coupling. SUMMARY STATEMENT: This study provides a phenotypic analysis of a novel mouse model of HANAC syndrome focusing on the retinal aspect. It recapitulates most of the aspects of the human disease and is therefore a great tool to study and to address this condition.

HANAC Syndrome Col4a1 Mutation Causes Neonate Glomerular Hyperpermeability and Adult Glomerulocystic Kidney Disease.

Hereditary angiopathy, nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is an autosomal dominant syndrome caused by mutations in COL4A1 that encodes the α1 chain of collagen IV, a major component of basement membranes. Patients present with cerebral small vessel disease, retinal tortuosity, muscle cramps, and kidney disease consisting of multiple renal cysts, chronic kidney failure, and sometimes hematuria. Mutations producing HANAC syndrome localize within the integrin binding site containing CB3[IV] fragment of the COL4A1 protein. To investigate the pathophysiology of HANAC syndrome, we generated mice harboring the Col4a1 p.Gly498Val mutation identified in a family with the syndrome. Col4a1 G498V mutation resulted in delayed glomerulogenesis and podocyte differentiation without reduction of nephron number, causing albuminuria and hematuria in newborns. The glomerular defects resolved within the first month, but glomerular cysts developed in 3-month-old mutant mice. Abnormal structure of Bowman's capsule was associated with metalloproteinase induction and activation of the glomerular parietal epithelial cells that abnormally expressed CD44,α-SMA, ILK, and DDR1. Inflammatory infiltrates were observed around glomeruli and arterioles. Homozygous Col4a1 G498V mutant mice additionally showed dysmorphic papillae and urinary concentration defects. These results reveal a developmental role for the α1α1α2 collagen IV molecule in the embryonic glomerular basement membrane, affecting podocyte differentiation. The observed association between molecular alteration of the collagenous network in Bowman's capsule of the mature kidney and activation of parietal epithelial cells, matrix remodeling, and inflammation may account for glomerular cyst development and CKD in patients with COL4A1-related disorders.

Case of H syndrome with massive skin involvement, retroperitoneal fibrosis and Raynaud's phenomenon with a novel mutation in the SLC29A3 gene.

We describe a case of H syndrome with massive skin involvement, retroperitoneal fibrosis and Raynaud's phenomenon. A 48-year-old man with parents of a consanguineous marriage, first appeared with decreased urine output, skin sclerosis on his inner thighs and short stature (142 cm, 47 kg). The patient had suffered from hearing loss since the age of 1 year, and his secondary sexual characteristics had not developed. Computed tomography showed periaortic fibrosis, bilateral ureteral stenosis, hydronephrosis and sclerosis of the germinal cords. A biopsy from the retroperitoneal mass revealed remarkable fibrosis with chronic inflammatory cells. Biopsies from the skin lesion showed thick collagen bundles through the dermis and lymphohistiocytic infiltration with numerous plasma cells. Serum inflammatory markers, such as C-reactive protein, vascular endothelial factor, transforming growth factor-ß and soluble interleukin-2 receptor, were elevated. Prednisolone was effective in treating skin lesions and in lowering serum inflammatory markers. After a long period of follow up, genomic DNA of the patient was obtained, and we identified a homozygous mutation in exon 5, c.625G>A, which caused transition of glycine to arginine, p.Gly208Arg, in the patient, but not in DNA samples from another 50 healthy individuals. This is the first case of H syndrome with Raynaud's phenomenon and retroperitoneal fibrosis, and the first Japanese case of H syndrome reported in the English published work with a novel mutation in the SLC29A3 gene.

Porencephaly in a fetus and HANAC in her father: variable expression of COL4A1 mutation.

COL4A1-associated disorders encompass a wide range of hereditary vasculopathy, including porencephaly and HANAC (adult-onset hemorrhagic stroke with cerebral aneurysm and retinal arterial tortuosity, renal cysts, and thenar muscle cramp). It remains elusive whether or not porencephaly and HANAC are molecularly distinctive disorders due to different classes of mutations. We report on a girl with porencephaly and an episode of microangiopathic hemolysis in infancy and her father with HANAC, both of whom had a heterozygous missense mutation of COL4A1 (c.3715G>A, p.G1239R). The current observation implies phenotypic diversities of COL4A1 mutations.

Primary biliary cirrhosis in a genetically homogeneous population: disease associations and familial occurrence rates.

BACKGROUND: Primary biliary cirrhosis (PBC) is a disease with genetic and environmental pathogenetic background. Chemicals, infectious agents, hormone therapy, reproductive history and surgical interventions have been implicated in the induction of PBC. Familial PBC has been documented in first degree relatives (FDR). Most cohort studies are genetically heterogeneous. Our study aimed to determine eventual lifestyle or disease associations and familial occurrence rates in a genetically homogeneous and geographically defined population of PBC patients. METHODS: 111 consenting PBC patients, were compared with 115 FDR and 149 controls matched for age, sex, Cretan origin and residence. All participants completed a questionnaire regarding demographics, lifestyle, medical, surgical and reproductive history. Significant variables on the univariate analysis were analyzed by multivariate analysis using a forward step-wise logistic regression model. RESULTS: Dyslipidaemia was found in 69.4% of patients, 60% of FDR and 40.9% of controls (p < 0.0001 and p = 0.003 respectively), autoimmune diseases in 36.9% of patients, 30.4% of FDR and 13.4% of controls (p < 0.0001 and p = 0.011 respectively). Hashimoto's disease (p = 0.003), Raynaud syndrome (p = 0.023) and Sjögren syndrome (p = 0.044) were significantly associated with PBC. On multivariate analysis statistically significant associations were found with primary educational level (AOR 2.304, 95% CI 1.024-5.181), cholecystectomy (AOR 2.927, 95% CI 1.347-6.362) and the presence of at least another autoimmune disease (AOR 3.318, 95% CI 1.177-6.22). Cancer history was more frequent in patients than in controls (p = 0.033). Familial PBC was found to be 9.9%. CONCLUSIONS: Dyslipidaemia and autoimmune diseases were significantly increased not only in patients as expected but also in their FDR. An increased prevalence of malignancies was found in patients. Primary educational level, cholecystectomy and the presence of at least another autoimmune disease were found as putative risk factors for PBC. No association was found with smoking, urinary tract infection or reproductive history. The reported high familial occurrence of PBC could imply screening with AMA of FDR with at least another autoimmune disease.

Glutathione S-transferase M1 and GST T1 genetic polymorphisms and Raynaud's phenomenon in French vinyl chloride monomer-exposed workers.

Occupational vinyl chloride monomer (VCM) exposure can induce Raynaud's phenomenon (RP). However, not all VCM workers developed RP, which suggests an underlying genetic susceptibility. Genetic polymorphisms of glutathione S-transferases (GSTs), involved in VCM metabolism, have been shown to influence certain VCM-related health effects. We have conducted a case-control study of 58 subjects with RP along with 247 subjects without RP, from a population of 305 French workers exposed or formerly exposed to VCM, to assess any association between GST M1 and GST T1 gene polymorphisms, either separately or in combination, and the presence of RP. None of the GST M1 or GST T1 genotypes were significantly associated with the presence of RP among studied VCM workers. A combination of positive genotypes for both GST M1 and GST T1 was significantly associated with RP presence, compared to the other combinations of genotypes (OR=2.1, 95% CI=1.1-3.8). OR adjusted for age, smoking status, alcohol consumption and history of treated hypertension did not reach significance (OR=2.0, 95% CI=0.9-5.2). None of the GST M1 and GST T1 genotypes seem to contribute separately to the presence of RP, suggesting that they are not, when taken alone, a major determinant of interindividual variability for VCM-induced PR. However, the combination of both positive GST M1 and GST T1 genotypes appears to contribute slightly to susceptibility to RP in VCM-exposed subjects. Nevertheless, our study-the first to examine the role of a genetic component in the occurrence of RP secondary to occupational exposure to a chemical-corroborates the previous considerations that interaction between the genetic constitution and environmental factors is of importance in determining the health-adverse effects of VCM exposure.

Familial clustering of Leiomyomatosis peritonealis disseminata: an unknown genetic syndrome?

BACKGROUND: Leiomyomatosis peritonealis disseminata (LPD) is defined as the occurrence of multiple tumorous intraabdominal lesions, which are myomatous nodules. LPD is a rare disease with only about 100 cases reported. The usual course of LPD is benign with the majority of the patients being premenopausal females. Only two cases involving men have been reported, no syndrome or familial occurrence of LPD has been described. CASE PRESENTATION: We describe a Caucasian-American family in which six members (three men) are diagnosed with Leiomyomatosis peritonealis disseminata (LPD) and three deceased family members most likely had LPD (based on the autopsy reports). Furthermore we describe the association of LPD with Raynaud's syndrome and Prurigo nodularis. CONCLUSION: Familial clustering of Leiomyomatosis peritonealis disseminata (LPD) has not been reported so far. The etiology of LPD is unknown and no mode of inheritance is known. We discuss possible modes of inheritance in the presented case, taking into account the possibility of a genetic syndrome. Given the similarity to other genetic syndromes with leiomyomatosis and skin alterations, we describe possible similar genetic pathomechanisms.

Association of novel polymorphisms with the expression of SPARC in normal fibroblasts and with susceptibility to scleroderma.

OBJECTIVE: Fibroblasts from patients with systemic sclerosis (SSc) have an activated phenotype characterized by increased synthesis of extracellular matrix (ECM) components. SPARC (secreted protein, acidic and rich in cysteine) regulates the deposition or assembly of ECM components. The aim of this study was to investigate the role of SPARC in SSc susceptibility by functional and genetic association studies. METHODS: Complementary DNA (cDNA) microarrays were used to obtain gene expression data on cultured dermal fibroblasts from SSc patients. SPARC protein levels were assessed by Western blotting. Five polymorphic microsatellite markers within 5 cM of the SPARC gene (chromosome 5q31-32) were genotyped in Choctaw Indians, a population previously shown to have a high prevalence of SSc. Discovery of single-nucleotide polymorphisms (SNPs) was accomplished by sequencing the SPARC cDNA. These SNPs were then genotyped in a multi-ethnic cohort of SSc patients to determine potential associations with disease susceptibility in a broader population of SSc patients, as well as with various clinical and immunologic features of SSc. The functional relevance of these SNPs with regard to transcript stability of SPARC was also assessed. RESULTS: Microarrays demonstrated increased expression of SPARC, along with other ECM genes, in SSc patients compared with normal controls. SSc fibroblasts also had increased SPARC protein levels. Three of 5 microsatellite markers near SPARC showed significant associations with SSc in the Choctaw SSc patients. Sequencing of SPARC cDNA revealed 3 novel SNPs in the 3'-untranslated region at +998 (C-->G), +1551 (C-->G), and +1922 (T-->G). Homozygosity for the C allele at SNP +998 was significantly increased in SSc patients across ethnic lines. SPARC SNPs +1551 and +1922 demonstrated correlations with Raynaud's phenomenon and pulmonary fibrosis, respectively. Functional studies of SPARC SNP +998 in normal fibroblast cultures suggested a correlation between the SNP +998 C allele polymorphism and an increased messenger RNA half-life. CONCLUSION: This study is the first to show that polymorphisms of the SPARC gene are associated with susceptibility to, and clinical manifestations of, SSc and that they may also be functionally important in influencing SPARC expression in skin fibroblasts.

Primary Raynaud's phenomenon. Age of onset and pathogenesis in a prospective study of 424 patients.

Many authors consider that late onset is a suspect criterion for differentiating primary Raynaud's phenomenon (Raynaud's disease, RD) from Raynaud's syndrome (RS). However, many cases of late-onset Raynaud's phenomenon in patients over forty years of age remain without etiologic diagnosis and therefore deserve the designation "late-onset RD." One hundred and ninety-four patients with RD (143 women, 51 men) were selected among 424 patients with Raynaud's phenomenon, according to Allen and Brown's criteria with negative serologic investigations and normal capillaroscopy. The purpose of the study was to consider the possible discriminant value of age of onset in distinguishing between RD and RS. The following epidemiologic features were studied: age of onset, sex, family history of Raynaud's phenomenon and migraine, and smoking and working habits. Microcirculation was assessed by capillaroscopy and strain-gauge plethysmography. Maximal digital flow at 45 degrees C and reactivity to cold were determined for each patient. Results were related to age of onset. The existence of true cases of late-onset RD in patients over forty years of age was confirmed (prevalence 27%), showing a correlation with a family history of Raynaud's phenomenon inferior to that found in early-onset cases (p < 0.0001). Microcirculation studies generally indicated a strong correlation between reactivity to cold, familial RD, and early onset, whereas no correlation was found with migraine or smoking. Nor was there any clinical or plethysmographic evidence for arteritis as a possible pathogenetic factor in late-onset RD. These results indicate that late-onset RD is a valid designation and that its pathogenesis seems less dependent on genetic sensitivity to cold than that of early-onset cases. In the absence of underlying arteritis, neurovascular dysfunction or a hemorheologic mechanism may be suggested as plausible causes of late-onset RD.

Two sisters producing anti-U1RNP exhibit serological concordance and clinical discordance.

Two sisters had autoimmune responses to the U1RNP particle that were quantitatively similar and/or identical in molecular characteristics. No other autoantibodies were demonstrable. Both sisters immunoprecipitated only U1RNA, had a reaction of identity in gel diffusion, bound the 68-kDa band in HeLa cell extract in Western blot, and reacted almost equally to a rabbit anti-idiotypic reagent made against either sister's isolated anti-U1RNP Fab fragments. They both carried a DR4 allele, which has been associated with anti-U1RNP production in several studies. While the sisters both had Raynaud's phenomenon, their clinical pictures were otherwise dissimilar. One had a seizure disorder (Ju); the other had polymyositis and features of scleroderma (Je). In sister Ju, Raynaud's phenomenon was manifest for the first time in association with the appearance of precipitating anti-U1RNP.

CENP-C, an autoantigen in scleroderma, is a component of the human inner kinetochore plate.

We have isolated and characterized a set of overlapping cDNA clones that encode the human centromere autoantigen centromere protein C (CENP-C). The identity of these clones has been established using several criteria. First, they were shown to encode a polypeptide that migrates at the expected position for CENP-C on SDS-polyacrylamide gel electrophoresis. Second, we have demonstrated that this polypeptide shares at least two epitopes with human CENP-C. Polyclonal antibodies were raised to fusion proteins encoded by nonoverlapping regions of the cDNA clones. These antibodies were shown to recognize a protein at a position appropriate for CENP-C on immunoblots of human chromosomal proteins. In addition, we used indirect immunofluorescence to demonstrate that these antibodies recognize centromeres of HeLa chromosomes in the expected pattern for CENP-C. Localization of CENP-C by immunoelectron microscopy reveals that this protein is a component of the inner kinetochore plate.

Diffuse palmoplantar keratoderma associated with acrocyanosis. A family study.

Four members of a family, in which 8 suffered from diffuse palmoplantar keratoderma associated with an uncommon form of acrocyanosis, are reported. Acrocyanosis and palmoplantar keratoderma do not always occur together and, therefore, an autosomal dominant inheritance for this association is suggested.

Raynaud's phenomenon in a female population: prevalence and association with other conditions.

In a random sample of 3000 women of ages eighteen to fifty-nine years in the city of Västerås, Sweden, 19% of the 2705 responders to a questionnaire complained of cold and white fingers with or without numbness. On the basis of interview and examination, 79% of these women were diagnosed as having Raynaud's phenomenon (RP), giving a prevalence of 15.6%. A significantly higher rate of family members with cold, white fingers was found only in the group of women with pronounced RP (p less than 0.001). A significantly higher frequency of women with pronounced RP than of the control group had a history of recurrent muscle/joint pain (p less than 0.05). Laboratory tests that might indicate an active connective tissue disease did not, however, confirm a diagnosis of rheumatoid arthritis. All three subgroups differed significantly from the control group in terms of recurrent chest pains; subgroups 2 and N differed significantly from controls in terms of recurrent headaches.

Three siblings with scleroderma (systemic sclerosis) and two with Raynaud's phenomenon from a single kindred.

A kindred is reported which contains 3 siblings with scleroderma, 2 siblings with Raynaud's phenomenon, and 2 first-degree relatives with histories suggestive of connective tissue syndromes. Studies of microvascular morphology and flow, serum endothelial cytotoxic activity, antinuclear antibodies, and HLA haplotypes in 18 relatives and 6 spouses revealed that 4 of 5 affected siblings expressed the HLA-DRw4 antigen, which was also present in 2 of 3 asymptomatic relatives whose serum contained endothelial cytotoxic activity. The evidence for an inherited susceptibility to scleroderma is reviewed.

The CREST syndrome variant of scleroderma in a mother-daughter pair.

The CREST syndrome variant of scleroderma was discovered in a 48 year old woman whose mother, age 70, also had CREST syndrome characterized by extensive skin involvement. HLA typing of the two patients, as well as the two asymptomatic daughters of the proband, revealed the A11-Bw22 haplotype. Review of the family relationships revealed two first cousin marriages. This is the fifth case report of vertical transmission of PSS or its variants, and the first report of this HLA type in such patients. An unusual feature of the illness in the mother was a large perforation of the nasal septum of the type usually associated with Wegener's disease.

Familial CRST syndrome with sicca complex.

Two patients, a mother and daughter, each with the CRST syndrome, developed Sjögren's syndrome. Both patients had mitochondrial antibodies, smooth muscle antibodies, and a raised serum IgM without clinical evidence of liver disease. This family constitutes the first record of the familial coexistence of the CRST syndrome with Sjögren's syndrome, and the second evidence of vertical inheritance of scleroderma. It is suggested that patients with the CRST syndrome be studied for Sjögren's syndrome and for autoimmune liver disease.