Mutations in FOXC2 Are Strongly Associated With Primary Valve Failure in Veins of the Lower Limb

Background— Mutations in the FOXC2 gene cause lymphedema distichiasis, an inherited primary lymphedema in which a significant number of patients have varicose veins. Because lymphedema distichiasis is believed to be caused by lymphatic valve failure (reflux), and FOXC2 is highly expressed on venous valves in mouse embryos, we tested the hypothesis that FOXC2 mutations may be linked to venous valve failure and reflux.

Methods and Results— The venous system of the leg was investigated with Duplex ultrasound. Pathological reflux was recorded by color Duplex ultrasound in all 18 participants with a FOXC2 mutation, including 3 without lymphedema. Every participant with a mutation in FOXC2 showed reflux in the great saphenous vein (n=18), compared with only 1 of 12 referents (including 10 family members; P <0.0001, Fisher exact test). Deep vein reflux was recorded in 14 of 18 participants.

Conclusions— FOXC2 is the first gene in which mutations have been strongly associated with primary venous valve failure in both the superficial and deep veins in the lower limb. This gene appears to be important for the normal development and maintenance of venous and lymphatic valves.

Varicose veins associated with CADASIL result from a novel mutation in the Notch3 gene

No genetically diagnosed cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) pedigrees with venous insufficiency have been described. In a CADASIL pedigree with varicose veins, the authors have identified a novel heterozygous mutation in the 3' splice acceptor site of intron 15 of the Notch3 gene. This, based on mRNA analysis, resulted in skipping of exon 16 including eight cysteine residues of EGF-like repeats.

Linkage to the FOXC2 region of chromosome 16 for varicose veins in otherwise healthy, unselected sibling pairs

BACKGROUND

The FOXC2 gene on 16q24 is mutated in lymphoedema distichiasis (LD), in which varicose veins (VV) are a common feature. We hypothesised that this gene might be implicated in the development of VV in the normal population, therefore, after performing a classical twin study, we tested for linkage and association in white women. We also tested for linkage with haemorrhoids (H), as a separate venous anomaly at the same locus.

METHODS

A total of 2060 complete female twin pairs aged 18-80 years from the St Thomas' Adult UK Twin registry replied to questions on VV and H as part of a broader postal survey of 6600 twins (62% response rate). Dizygotic female twin pairs were tested for linkage and association to the candidate marker D16S520 (1903 individuals genotyped), which is located about 80 kb from FOXC2.

RESULTS

Casewise concordance rates were significantly higher for monozygotic than dizygotic twins for both phenotypes (VV 67% v 45%; p = 2.2x10(-6); H 68% v 59%; p = 0.01; H including during pregnancy 73% v 64%; p = 2.1x10(-4)), corresponding to additive genetic heritabilities in liability of 86% (95% confidence interval (CI) 73% to 99%) for VV and 56-61% for H (95% CI 43% to 73%). The presence of VV and H were significantly correlated. We found significant evidence of linkage to the marker for VV (MLS(ASP) = 1.37, p = 0.01; GLM(ASP/DSP) Z = 3.17 p = 0.002), but no association. Both linkage and association tests were negative for H. The combined phenotype of having VV and H did not show any evidence of linkage or association.

CONCLUSION

These results demonstrate VV and H to be heritable, related conditions, and the data strongly suggest FOXC2 to be implicated in the development of VV in the general population.

Gene expression profiles in varicose veins using complementary DNA microarray

BACKGROUND

There has been little information reported about the genetic event concerning the pathophysiology of varicose vein (VV).

OBJECTIVES

The purpose of this study was to examine the differentiation of gene expression in the wall of VV using complementary deoxyribonucleic acid (cDNA) microarrays.

METHODS

The study was performed with four pairs of VVs and control veins (CVs). cDNA specimens of VVs were prepared from the ribonucleic acid-isolated VVs of patients who underwent venous obliteration, using radiofrequency, as well as from CVs of those who underwent aortocoronary bypass grafting. Each set of VVs and CVs was hybridized with high-density microarray containing 3,063 human cDNAs. The finding of microarray hybridization were scanned, analyzed, and classified with the cluster program.

RESULTS

Among 3,063 cDNA clones, 82 genes were up-regulated in VVs, and some of the up-regulated genes, which were detected by cDNA microarray, including transforming growth factor 3-induced gene (BIGH3), tubulin, lumican, actinin, collagen type I, versican, actin, and tropomyosin, belonged to extracelluar matrix molecules, cytoskeletal proteins, or myofibroblasts.

CONCLUSIONS

Many up-regulated genes were found in Ws by applying cDNA microarray. These gene profiles suggested a pathway associated with fibrosis and that wound healing might be related to the pathophysiology of VVs.

Identification of differentially expressed genes in primary varicose veins

BACKGROUND

A number of changes in protein expression have been described in primary varicose veins, but the altered gene expressions in this disease are unknown. The aim of this study was to identify differentially expressed genes in primary varicose veins.

MATERIALS AND METHODS

Total RNAs were isolated from two groups of greater saphenous veins (four primary varicose veins and three normal) and then were reverse transcribed into cDNAs. We used the differential display reverse transcription-polymerase chain reaction technique to screen the differences in the mRNA expression profiles of the groups.

RESULTS

We found that three cDNAs showed differences in expression patterns between normal and diseased saphenous veins. The cDNAs are prominently expressed only in patients with varicose veins. We identified that the cDNAs had significant similarities to the L1M4 repeat sequence of clone RP11-57L9, clone RP11-299H13, and Alu repetitive sequence of human tropomyosin 4 mRNA.

CONCLUSIONS

Our results suggest that the screened cDNA clones are useful disease markers in the genetic diagnosis of primary varicose vein and that the L1 and Alu elements possibly participated in the development of primary varicose veins through their expression patterns in genes encoded with structural proteins, such as collagen, elastin, and tropomyosin. Further studies are required to elucidate the potential relationship between repeat sequences and primary varicose veins.

Primary Varicose Veins: Altered Transcription of VEGF and its Receptors (KDR, flt-1, Soluble flt-1) with Sapheno-femoral Junction Incompetence

OBJECTIVE

Loss of regulation of vascular endothelial growth factor (VEGF) production and action disturbs vascular homeostasis leading to pathology. Primary varicose veins (VVs) demonstrate aberrant production/release of VEGF. Our aim was to examine transcription of genes for VEGF (VEGF(121)/VEGF(165)) and its receptors (KDR, flt-1, s.flt-1) in VVs, in relation to underlying venous incompetence.

MATERIALS AND METHODS

Samples of varicose (n=83, 18 patients) or normal (n=14, five subjects) great saphenous vein were divided into segments, determined by anatomical position from the sapheno-femoral junction (SFJ). SFJ and segmental incompetence were determined from duplex scans. Gene transcripts were amplified by RT-PCR, analysed by scanning densitometry, and the levels of transcription determined by ratio to control gene GADPH-3 (GAP-3).

RESULTS

VEGF(121)/(165), KDR and flt-1 transcription was elevated in VVs overall (p<0.001), and in VVs with an incompetent SFJ (p<0.001), but not when the SFJ was functional; s.flt-1 was unaltered. Notably, gene transcription was unaffected by segmental position, or incompetence. Position below the SFJ correlated with increased transcription of s.flt-1 when the SFJ was incompetent (p<0.04), and s.flt-1 and VEGF(121) when the segment was incompetent (p<0.03).

CONCLUSIONS

SFJ incompetence is associated with altered transcription of VEGF and its receptors reflecting an aetiological mechanism or later stage of disease development. Altered VEGF(121) and s.flt-1 transcription may be an early event in varicogenesis.

Chronic venous insufficiency: the genetic influence

Many contributing factors are involved in the genesis of varicose disease of the lower limbs such as age, sex, heredity, sedentary life style among others. For physicians the decisive role played by heredity leaves no doubt. Few studies have, however, attempted to prove the importance of the hereditary factor on a clinical level, and no study has been conducted in molecular genetics. The impact of the hereditary factor is variably estimated and its nature is open to discussion. Despite the numerous limits of the research focusing on the hereditary aspect of varicose disease, the authors can nevertheless claim that the genetic factor definitively exists and has a great impact. There are few studies conducted among twins. The data collected in these studies point to the reality of various types of heredity. With the predominant impact of the hereditary factor, and despite the role played by environmental factors, it can be supposed that a single genetic anomaly may be the determining factor of the disease in a given family. Thus we have conducted an original study in order to identify one or several mutations predisposing to varicose disease, based on the approach called "reverse genetic" and linkage study. The study of a first family whose varicose disease segregates in an autosomal dominant manner allowed us to identify 3 potential loci, if we accept the hypothesis of 2 or 3 phenocopies. No candidate gene has been singled out in these regions in the first analysis. The study of a second family whose phenotype of the varicose disease is particularly homogeneous and segregates in an autosomal dominant manner did not confirm any of the previously identified loci, probably related to a genetic heterogeneity of the varicose disease. As a consequence, the second part of this study was devoted to determining the complete genotype of each individual within this family, in order to identify new loci of interest. A potential locus has just been identified. The third part of this research, currently being pursued, is devoted to the sequencing of potential genes. In parallel, the analysis of new large families is underway. The presentation will include an update on the hereditary and genetic aspects of varicose disease, and secondly identify the limits and difficulties of the genetic study of the families.

[Default of KIAA0353 gene in varicose great saphenous vein accompanying primary deep vein valve insufficiency]

OBJECTIVE

To screen and identify the genes related to the occurrence and development of varicose great saphenous vein in the patients with primary deep vein valve insufficiency (PDVI).

METHODS

mRNA fluorescent differential display (FDD) technique was used to compare the different cDNA fragments originated from differentially expressed mRNAs from the venous tissues of 10 patients with varicose great saphenous vein complicated with PDVI. Ten specimens of normal venous tissue from 10 patients dying from other diseases were used as controls. The differently expressed cDNA fragments were then re-amplified and labeled with DIG to prepare probes for later Northern blotting. Positive fragments confirmed by Northern blotting were cloned into pGEM-T easy vector and sequenced using Sanger's method. Then the sequences were compared with the data in GeneBank by BLASTN software to search for their genetic origin.

RESULTS

Altogether 37 differentially expressed cDNA fragments were discovered from the 2 groups, among which 30 were confirmed by Northern blotting. There was a notable 540 bp-long cDNA fragment, which was only presented in the control group, sharing 99% homology with part of the mRNA sequence of human KIAA0353 gene.

CONCLUSION

The varicose great saphenous vein of PDVI patients is a process with the involvement of multiple genes and the default of KIAA0353 gene may play a role in the occurrence and development of varicose great saphenous vein in PDVI patients.

Increased mast cell infiltration in familial varicose veins: pathogenetic implications?

AIM

Increased infiltration of activated mast cells has been recently implicated in the pathophysiology of varicose veins. The aim of the present study was to investigate a possible association between mast cell infiltration of primary varicose veins and clinical features, which could clarify further varicose vein pathophysiology.

METHODS

Seventeen patients, operated on for primary varicose veins and greater saphenous vein incompetence, participated in the study. Mast cells, distributed within the adventitia of grossly abnormal segments of the greater saphenous vein and calf varicosities removed during surgery, were identified and measured in stained tissue sections. The mast cell count, expressed as mast cells per 10 high-power fields, was subsequently associated with clinical features, including age, gender, body mass index, familial varicose veins, duration of varicose vein disease and relation to previous pregnancies, leg symptoms and findings on physical examination, clinical class and score of chronic venous insufficiency (CEAP classification).

RESULTS

Patients with family history of varicose veins (n=7) had a significantly increased mast cell infiltration (median, interquartile range) of the abnormal venous segments (16, 8.4) in comparison with those (n=10) without such a history (9.2, 7.3), p=0.005. Mast cell infiltration had a significant inverse association with age (r= -0.49, p=0.046), but not with the remaining clinical features.

CONCLUSION

Our findings support the hypothesis that the increased mast cell infiltration in varicose veins is not a consequence of venous hypertension. Furthermore, the increased mast cell infiltration in familial varicose veins implies a rather primary role and therefore the presence of a distinct pathophysiology. Further investigation testing the activity of mast cells in cases of family history might reveal another step in the pathogenic mechanism of varicose veins, leading to a more rational treatment.

[Vascular manifestation of von Recklinghausen neurofibromatosis: case report of venous dysplasia]

We present the case report of a patient with neurofibromatosis and regional dysmorphism in the superficial femoral vein. Colour coded duplex sonography revealed an incidental finding: thickening of a short portion of the vein wall with calcification. This unusual finding strongly suggests a causal relationship. Pathological processes in the arteries have often been described in patients with von Recklinghausen's disease (neurofibromatosis). Dysplastic and hyperplastic reactions of the intramural nerve tissues and the smooth muscle elements in the vascular wall have been observed. This leads to the formation of aneurysms and arteriovenous fistulas and to stenosing processes in the peripheral, visceral and cerebral arteries. However, involvement of the veins in type 1 von Recklinghausen's neurofibromatosis has only been reported in old histopathological studies of medium-sized and small vessels.

[Screening and cloning of genes related to varicose great saphenous vein accompanying with primary deep vein valve insufficiency]

OBJECTIVE

To screen the genes related to the occurrence and development of varicosis of the great saphenous vein in the patients with primary deep vein valve insufficiency.

METHODS

Using mRNA fluorescent differential display reverse transcriptive polymerase chain reaction (FDD-RTPCR), different genes expressed in the varicose great saphenous veins in patients with primary deep vein valve insufficiency and corresponding normal human tissues were compared. Differentially expressed cDNA fragments confirmed by Northern blot were compared and then cloned into the pGEM-Teasy vector. Positive clones were selected and sequenced. All the sequences were put into GenBank and analyzed by BLASTN software to search for their genetic origins.

RESULTS

Altogether 37 different cDNA fragments were obtained and 30 of which were confirmed by Northern blot. Analysis of the sequences by BLASTN software showed that C(610) fragment (NO. 18 cDNA clone) shared 96% homology with the mRNA sequence of the human Mckusick-Kaufman syndrome gene (MKKS gene).

CONCLUSION

C(610) fragment is highly homologous with the mRNA sequence of the human MKKS gene and is closely related to the development of varicosis of the great saphenous vein in patients with primary deep vein valve insufficiency.

Synthesis of collagen is dysregulated in cultured fibroblasts derived from skin of subjects with varicose veins as it is in venous smooth muscle cells

BACKGROUND

The dilatation and tortuosity observed in varicose veins provide evidence for progressive venous wall remodeling associated with abnormalities of smooth muscle cells and extracellular matrix. The present study was designed to examine if the phenotypic modulations observed in the venous smooth muscle cells of patients with varicose veins were also present in their dermal fibroblasts.

METHODS AND RESULTS

Collagen type I (collagen I), type III (collagen III), and type V (collagen V) were compared in dermal fibroblasts derived from the skin of control subjects and patients with varicose veins. The synthesis of collagen I, the release of its metabolites, and the expression of its mRNA were increased in fibroblasts from patients with varicose veins, whereas the synthesis of collagen III was decreased but not correlated with a decrease in mRNA expression and in metabolite release. Matrix metalloproteinases (MMP1, 2, 7, 8, 9, and 13) and their inhibitors (TIMP1 and 2) were quantified in both cell types; only the production of proMMP2 was increased in cells derived from patients with varicose veins.

CONCLUSIONS

These findings suggest that the synthesis of collagen I and III is dysregulated in dermal fibroblasts derived from patients with varicose veins. These results are comparable with those observed in smooth muscle cells derived from varicose veins, thus suggesting a systemic alteration of tissue remodeling in subjects with varicose veins.

Diagnosis and treatment in the management of chronic venous insufficiency

Chronic venous insufficiency (CVI) is caused mainly by an alteration in the elasticity of venous walls and the dysfunction of venous valves. The diagnosis and treatment for CVI management are discussed in this paper.

Thrombomodulin promoter mutations, venous thrombosis, and varicose veins

We analyzed the distal promoter region of the thrombomodulin (TM) gene (nucleotides -300 to -2052) in subjects from the Paris Thrombosis Study (PATHROS), a French case-control study of venous thrombosis, to identify polymorphisms that might modify TM gene expression. Eight novel mutations were found in the 40 DNA samples initially screened. Two of these mutations (-1748G/C and -1208/-1209 del TT) were frequent. One rare transition (-1166G/A) might have functional consequences owing to its position. These 3 mutations were screened for in the entire study population of 327 patients and 398 controls. None of the 3 was significantly associated with thrombosis. Interestingly, the -1208/-1209 TT deletion was associated with varicose veins in the patients. This mutation was in tight linkage disequilibrium with the +1418 C/T change in the coding sequence, a known polymorphism that predicts an Ala 455 Val substitution in the sixth epidermal growth factor-like TM module, a domain previously implicated in the proliferative functions of TM. This linkage suggests that the Ala 455 Val mutation may promote changes in these functions and thus be involved in varicose vein formation.

[Contents of the main erythrocyte membrane proteins in patients with primary arterial hypertension and its relationship with hereditary predisposition to cardiovascular diseases]

AIM

To study quantitative content of main erythrocyte membrane proteins in patients with primary arterial hypotension and its relationship with hereditary predisposition to cardiovascular disease.

MATERIAL AND METHODS

Quantitative content of main erythrocyte membrane proteins in 109 patients with primary arterial hypotension (PAH) and 124 healthy persons was measured with unidimensional polyacrylamide gel electrophoresis. Hereditary determination of PAH was studied by the clinical-genealogical method.

RESULTS

PAH patients showed quantitative alterations in erythrocyte membrane protein composition: increased content of alpha-spectrin, ankyrin (band 2.1), anion exchange protein (band 3) and decreased content of actin, tropomyosin and glutathione-S-transferase. Patients with aggravated heredity for PAH had higher content of beta-spectrin and ankyrin (band 2.1 and 2.2) then patients without aggravated heredity for PAH.

CONCLUSION

Quantitative alterations of membrane proteins in patients with PAH could significantly modify the structure of cytoskeleton and result in modification of the enzyme activity of transmembrane proteins (ATPases) regulating cation transport across erythrocyte membrane. Moreover, aggravated heredity for PAH predisposes to high content of cytoskeletal proteins (beta-spectrin, 2.1 and 2.2 ankyrin) which could form more compact structure of erythrocyte membrane and limit cation influx into cytoplasma.

[Familial colonic varices: report of two cases]

Idiopathic or familial colonic varices are an infrequent cause of gastrointestinal hemorrhage. It seems that congenital vascular abnormalities are involved in its etiopathogenesis. We present two cases in the same family. The disease first presented as intermittent episodes of rectorrhagia. In one case varices of the small intestine were detected by radiology. Both cases were given conservative treatment and we believe that surgery should be limited to selected cases and always after a careful observation period.

Expression of p21WAF1/CIP1, p53, bcl-2 and Ki-67 in venous leg ulcers with and without squamous cell carcinoma

In order to gain understanding of the cellular mechanisms of malignant transformation in chronic venous leg ulcers, we analysed by immunohistochemistry the presence of p21, p53, bcl-2 and Ki-67 in ulcers with and without squamous cell carcinoma. The material consisted of 41 archived histopathological samples from 33 patients with chronic venous leg ulcers and 28 samples from 21 patients suffering from squamous cell carcinoma in chronic venous leg ulcers. All samples derived from the chronic ulcers were negative for p53, p21 and bcl-2. Cells positive for Ki-67 were seen in certain ulcer areas. In the cancers, 14 samples showed immunopositivity for p53 and 22 samples were positive for p21, with expression mainly in the suprabasal layer. Expression of p21 seemed independent of p53. None of the samples was bcl-2-positive. Ki-67 was positive with basal expression in 16/28 of the tumour samples, 15 of which also expressed p21. There was no perilesional p53 or p21 activity in the cancer samples. The results regarding perilesional expression are different from those reported in UV-induced squamous cell carcinomas and probably reflect a different carcinogen.

Physiological reflux and venous diameter change in the proximal lower limb veins during a standardised Valsalva manoeuvre

OBJECTIVES

the aim of this study was to provide normal values for venous diameter at rest, and venous diameter and physiologic venous reflux during a standardised Valsalva manoeuvre. The impact of the patient's sex, body mass index (BMI), and family history was investigated.

MATERIAL AND METHODS

eighty legs of 40 healthy volunteers were investigated in a supine position. The median age was 28 years (range 20-66 years). The common femoral vein (CFV), the proximal superficial femoral vein (SFV) and the proximal long saphenous vein (LSV) were investigated by duplex sonography. The following parameters were assessed: resting diameter (VDrest) and maximum diameter (VDmax) as well as reflux time (tr) during the Valsalva manoeuvre. The Valsalva manoeuvre was elicited by a forceful expiration into a tube system. The standard values used were a pressure of 30 mmHg, established within 0.5 seconds (s) and maintained over a time period of at least 3 s.

RESULTS

mean VDrest and VDmax were 8.3+/-2.2 and 11.1+/-2.8 mm in the CFV, 5.9+/-1. 3 and 7.2+/-1.6 mm in the SFV and 3.5+/-0.9 and 4.3+/-1.4 mm in the LSV. Mean values for tr were 0.61+/-0.63 s in the CFV, 0.25+/-0.26 s in the SFV and 0.28+/-0.40 s in the LSV. A BMI >22.5 kg/m2 was associated with statistically significant larger values for VDrest and tr. If adjusted for BMI, tr in the SFV and the LSV did not differ by sex. For healthy subjects with first-degree relatives suffering from varicose veins (n=19), mean VDrest in the SFV as well as VD in the LSV was significantly larger (p=0.02, 0.05, respectively). Coefficients of variation for repeated measurements (VDrest, VDmax, tr) in the same segment varied between 3.3% and 16. 4% for the three investigated sites.

CONCLUSIONS

normal values for VDrest and VDmax as well as reflux time during a standardised Valsalva manouevre were assessed in the proximal lower limb veins. The influences of BMI, sex and family history were investigated. The described standardised Valsalva manoeuvre led to highly reproducible results and can be recommended for further research projects or as a routine procedure for the assessment of venous reflux.

[Familial varices of the colon. Report of four cases]

We report four cases of ileo-colonic varices in one family. This congenital disease is uncommon with only 21 cases described in the literature. Recurrent digestive tract bleeding is the most common manifestation, but varices can be asymptomatic. Digestive endoscopy leads to the diagnosis. The diagnosis of familial colonic varices can be considered when colonic varices occur in several members of a family with no evident cause, particularly portal hypertension or venous thrombosis. No treatment is usually necessary except when major or recurrent bleeding indicates surgical resection. These malformations are classified as vascular ectasia in the subgroup of cavernous haemangiomas.

[Genetic analysis of varicose vein of lower extremities]

OBJECTIVE

To make a hereditary analysis of varicose vein of lower extremities(VVLE), including hereditary pattern, sex ratio and the transmitted expression male and female of varicose vein of lower extremities.

METHODS

The ascertainment probability was estimated according to Weinberg's proband method. The value of segregation ratio P and proportion of sporadic cases X were estimated by the maximum likelihood score method. The calculations were performed using computer program of segregation analysis. The VVLE cases were random samples from inpatients and outpatients of the authors' hospital from 1991 to 1996.

RESULTS

There were 68 pedigrees including 80 nuclear families in 3 different mating types:UAU, UAA and AAA. UAU, UAA and AAA were analysed together. UAA and UAU (multiplex families) were analysed respectively. All the values were compatible with autosomal dominant inheritance of incomplete penetrance; the penetrance frequencies were 91.94%, 78.14% and 69. 92% respectively. The proportion of X was 24.32%. The UAU was compatible with autosomal recessive inheritance; the proportion of sporadic cases was 36.75%.

CONCLUSION

VVLE is compatible with autosomal dominant and recessive inheritance. The sex ratio of male:female is 2.39:1. The transmission is possible from male and female to male and female both.

A new case of Klippel-Trenaunay-Weber (KTW) syndrome: evidence of autosomal dominant inheritance

Most cases of KTW syndrome are sporadic. However, in a few, other family members have some clinical manifestations of the syndrome, and an autosomal dominant mode of inheritance has been suggested. In this paper we present a family with an affected child who has large skin hemangiomata, overgrowth of the right leg, and severe heart defects. Her mother has a large capillary hemangioma on the left side of back and has developed severe varicosities in both lower extremities. The maternal grandmother developed severe varicosities in her legs at a young age. The clinical signs found in the mother and maternal grandmother represent a milder phenotype and might be explained as variable expressivity of the syndrome. The family tree supports autosomal dominant inheritance.