Association between presence of HLA-B*5701, HLA-DR7, and HLA-DQ3 and hypersensitivity to HIV-1 reverse-transcriptase inhibitor abacavir

BACKGROUND

The use of abacavir--a potent HIV-1 nucleoside-analogue reverse-transcriptase inhibitor--is complicated by a potentially life-threatening hypersensitivity syndrome in about 5% of cases. Genetic factors influencing the immune response to abacavir might confer susceptibility. We aimed to find associations between MHC alleles and abacavir hypersensitivity in HIV-1-positive individuals treated with abacavir.

METHODS

MHC region typing was done in the first 200 Western Australian HIV Cohort Study participants exposed to abacavir. Definite abacavir hypersensitivity was identified in 18 cases, and was excluded in 167 individuals with more than 6 weeks' exposure to the drug (abacavir tolerant). 15 individuals experienced some symptoms but did not meet criteria for abacavir hypersensitivity. p values were corrected for comparisons of multiple HLA alleles (p(c)) by multiplication of the raw p value by the estimated number of HLA alleles present within the loci examined.

FINDINGS

HLA-B*5701 was present in 14 (78%) of the 18 patients with abacavir hypersensitivity, and in four (2%) of the 167 abacavir tolerant patients (odds ratio 117 [95% CI 29-481], p(c)<0.0001), and the HLA-DR7 and HLA-DQ3 combination was found in 13 (72%) of hypersensitive and five (3%) of tolerant patients (73 [20-268], p(c)<0.0001 ). HLA-B*5701, HLA-DR7, and HLA-DQ3 were present in combination in 13 (72%) hypersensitive patients and none of the tolerant patients (822 [43-15 675], p(c)<0.0001). Other MHC markers also present on the 57.1 ancestral haplotype to which the three markers above belong confirmed the presence of haplotype-specific linkage disequilibrium, and mapped potential susceptibility loci to a region bounded by C4A6 and HLA-C. Within the entire abacavir-exposed cohort (n=200), presence of HLA-B*5701, HLA-DR7, and HLA-DQ3 had a positive predictive value for hypersensitivity of 100%, and a negative predictive value of 97%.

INTERPRETATION

Genetic susceptibility to abacavir hypersensitivity is carried on the 57.1 ancestral haplotype. In our population, withholding abacavir in those with HLA-B*5701, HLA-DR7, and HLA-DQ3 should reduce the prevalence of hypersensitivity from 9% to 2.5% without inappropriately denying abacavir to any patient.

Tat-mediated delivery of heterologous proteins into cells

The Tat protein of human immunodeficiency virus 1 (HIV-1) can enter cells efficiently when added exogenously in tissue culture. To assess if Tat can carry other molecules into cells, we chemically cross-linked Tat peptides (residues 1-72 or 37-72) to beta-galactosidase, horseradish peroxidase, RNase A, and domain III of Pseudomonas exotoxin A (PE) and monitored uptake colorimetrically or by cytotoxicity. The Tat chimeras were effective on all cell types tested, with staining showing uptake into all cells in each experiment. In mice, treatment with Tat-beta-galactosidase chimeras resulted in delivery to several tissues, with high levels in heart, liver, and spleen, low-to-moderate levels in lung and skeletal muscle, and little or no activity in kidney and brain. The primary target within these tissues was the cells surrounding the blood vessels, suggesting endothelial cells, Kupffer cells, and/or splenic macrophages. Tat-mediated uptake may allow the therapeutic delivery of macromolecules previously thought to be impermeable to living cells.

Formation of mRNA 3' ends in eukaryotes: mechanism, regulation, and interrelationships with other steps in mRNA synthesis

Formation of mRNA 3' ends in eukaryotes requires the interaction of transacting factors with cis-acting signal elements on the RNA precursor by two distinct mechanisms, one for the cleavage of most replication-dependent histone transcripts and the other for cleavage and polyadenylation of the majority of eukaryotic mRNAs. Most of the basic factors have now been identified, as well as some of the key protein-protein and RNA-protein interactions. This processing can be regulated by changing the levels or activity of basic factors or by using activators and repressors, many of which are components of the splicing machinery. These regulatory mechanisms act during differentiation, progression through the cell cycle, or viral infections. Recent findings suggest that the association of cleavage/polyadenylation factors with the transcriptional complex via the carboxyl-terminal domain of the RNA polymerase II (Pol II) large subunit is the means by which the cell restricts polyadenylation to Pol II transcripts. The processing of 3' ends is also important for transcription termination downstream of cleavage sites and for assembly of an export-competent mRNA. The progress of the last few years points to a remarkable coordination and cooperativity in the steps leading to the appearance of translatable mRNA in the cytoplasm.

Spliced segments at the 5' terminus of adenovirus 2 late mRNA

An mRNA fraction coding for hexon polypeptide, the major virion structural protein, was purified by gel electrophoresis from extracts of adenovirus 2-infected cells late in the lytic cycle. The mRNA sequences in this fraction were mapped between 51.7 and 61.3 units on the genome by visualizing RNA-DNA hybrids in the electron microscope. When hybrids of hexon mRNA and single-stranded restriction endonuclease cleavage fragments of viral DNA were visualized in the electron microscope,branched forms were observed in which 160 nucleotides of RNA from the 5' terminus were not hydrogen bonded to the single-stranded DNA. DNA sequences complementary to the RNA sequences in each 5' tail were found by electron microscopy to be located at 17, 20, and 27 units on the same strand as that coding for the body of the hexon mRNA. Thus, four segments of viral RNA may be joined together during the synthesis of mature hexon mRNA. A model is presented for adenovirus late mRNA synthesis that involves multiple splicing during maturation of a larger precursor nuclear RNA.

Very low doses of warfarin can prevent thrombosis in central venous catheters. A randomized prospective trial

OBJECTIVE

To determine whether very low doses of warfarin are useful in thrombosis prophylaxis in patients with central venous catheters.

DESIGN

Patients at risk for thrombosis associated with chronic indwelling central venous catheters were prospectively and randomly assigned to receive or not to receive 1 mg of warfarin, beginning 3 days before catheter insertion and continuing for 90 days. Subclavian, innominate, and superior vena cava venograms were done at onset of thrombosis symptoms or after 90 days in the study.

RESULTS

One hundred twenty-one patients entered the study, and 82 patients completed the study. Of 42 patients completing the study while receiving warfarin, 4 had venogram-proven thrombosis. All 4 had symptoms from thrombosis. Of 40 patients completing the study while not receiving warfarin, 15 had venogram-proven thrombosis, and 10 had symptoms from thrombosis (P less than 0.001). There were no measurable changes in the coagulation values assayed due to this warfarin dose, except in occasional patients who had become anorectic because of their disease or chemotherapy.

CONCLUSIONS

Very low doses of warfarin can protect against thrombosis without inducing a hemorrhagic state. This approach may be applicable to other groups of patients.

c-Jun regulates cell cycle progression and apoptosis by distinct mechanisms

c-Jun is a component of the transcription factor AP-1, which is activated by a wide variety of extracellular stimuli. The regulation of c-Jun is complex and involves both increases in the levels of c-Jun protein as well as phosphorylation of specific serines (63 and 73) by Jun N-terminal kinase (JNK). We have used fibroblasts derived from c-Jun null embryos to define the role of c-Jun in two separate processes: cell growth and apoptosis. We show that in fibroblasts, c-Jun is required for progression through the G1 phase of the cell cycle; c-Jun-mediated G1 progression occurs by a mechanism that involves direct transcriptional control of the cyclin D1 gene, establishing a molecular link between growth factor signaling and cell cycle regulators. In addition, c-Jun protects cells from UV-induced cell death and cooperates with NF-kappaB to prevent apoptosis induced by tumor necrosis factor alpha (TNFalpha). c-Jun mediated G1 progression is independent of phosphorylation of serines 63/73; however, protection from apoptosis in response to UV, a potent inducer of JNK/SAP kinase activity, requires serines 63/73. The results reveal critical roles for c-Jun in two different cellular processes and show that different extracellular stimuli can target c-Jun by distinct biochemical mechanisms.

Further evidence for family-genetic risk factors in attention deficit hyperactivity disorder. Patterns of comorbidity in probands and relatives psychiatrically and pediatrically referred samples

We examined 140 probands with attention deficit hyperactivity disorder, 120 normal controls, and their 822 first-degree relatives using "blind" raters and structured diagnostic interviews. Compared with controls, probands with attention deficit hyperactivity disorder were more likely to have conduct, mood, and anxiety disorders. Compared with relatives of controls, relatives of probands with attention deficit hyperactivity disorder had a higher risk for attention deficit hyperactivity disorder, antisocial disorders, major depressive disorder, substance dependence, and anxiety disorders. Patterns of comorbidity indicate that attention deficit hyperactivity disorder and major depressive disorders may share common familial vulnerabilities, that attention deficit hyperactivity disorder plus conduct disorder may be a distinct subtype, and that attention deficit hyperactivity disorder and anxiety disorders are transmitted independently in families. These results extend previous findings indicating family-genetic influences in attention deficit hyperactivity disorder by using both pediatrically and psychiatrically referred proband samples. The distributions of comorbid illnesses in families provide further validation for subgrouping probands with attention deficit hyperactivity disorder by comorbidity.

The trouble with cognitive subtraction

In this paper we present a critique of pure insertion. Pure insertion represents an implicit assumption behind many (but not all) studies that employ cognitive subtraction. The main contention is that pure insertion is not valid in relation to the neuronal instantiation of cognitive processes. Pure insertion asserts that there are no interactions among the cognitive components of a task. It is possible to evaluate and refute this assumption by testing explicitly for interactions using factorial experimental designs. It is proposed that factorial designs are more powerful than subtraction designs in characterizing cognitive neuroanatomy, precisely because they allow for interactions and eschew notions like pure insertion. In particular we suggest that the effect of a cognitive component (i.e., an effect that is independent of other components) is best captured by the main (activation) effect of that component and that the integration among components (i.e., the expression of one cognitive process in the context of another) can be assessed with the interaction terms. In this framework a complete characterization of cognitive neuroanatomy includes both regionally specific activations and regionally specific interactions. To illustrate our point we have used a factorial experimental design to show that inferotemporal activations, due to object recognition, are profoundly modulated by phonological retrieval of the object's name. This interaction implicates the inferotemporal regions in phonological retrieval, during object naming, despite the fact that phonological retrieval does not, by itself, activate this region.

Epidemics and percolation in small-world networks

We study some simple models of disease transmission on small-world networks, in which either the probability of infection by a disease or the probability of its transmission is varied, or both. The resulting models display epidemic behavior when the infection or transmission probability rises above the threshold for site or bond percolation on the network, and we give exact solutions for the position of this threshold in a variety of cases. We confirm our analytic results by numerical simulation.

Integrating primary medical care with addiction treatment: a randomized controlled trial

CONTEXT

The prevalence of medical disorders is high among substance abuse patients, yet medical services are seldom provided in coordination with substance abuse treatment.

OBJECTIVE

To examine differences in treatment outcomes and costs between integrated and independent models of medical and substance abuse care as well as the effect of integrated care in a subgroup of patients with substance abuse-related medical conditions (SAMCs).

DESIGN

Randomized controlled trial conducted between April 1997 and December 1998.

SETTING AND PATIENTS

Adult men and women (n = 592) who were admitted to a large health maintenance organization chemical dependency program in Sacramento, Calif.

INTERVENTIONS

Patients were randomly assigned to receive treatment through an integrated model, in which primary health care was included within the addiction treatment program (n = 285), or an independent treatment-as-usual model, in which primary care and substance abuse treatment were provided separately (n = 307). Both programs were group based and lasted 8 weeks, with 10 months of aftercare available.

MAIN OUTCOME MEASURES

Abstinence outcomes, treatment utilization, and costs 6 months after randomization.

RESULTS

Both groups showed improvement on all drug and alcohol measures. Overall, there were no differences in total abstinence rates between the integrated care and independent care groups (68% vs 63%, P =.18). For patients without SAMCs, there were also no differences in abstinence rates (integrated care, 66% vs independent care, 73%; P =.23) and there was a slight but nonsignificant trend of higher costs for the integrated care group ($367.96 vs $324.09, P =.19). However, patients with SAMCs (n = 341) were more likely to be abstinent in the integrated care group than the independent care group (69% vs 55%, P =.006; odds ratio [OR], 1.90; 95% confidence interval [CI], 1.22-2.97). This was true for both those with medical (OR, 3.38; 95% CI, 1.68-6.80) and psychiatric (OR, 2.10; 95% CI, 1.04-4.25) SAMCs. Patients with SAMCs had a slight but nonsignificant trend of higher costs in the integrated care group ($470.81 vs $427.95, P =.14). The incremental cost-effectiveness ratio per additional abstinent patient with an SAMC in the integrated care group was $1581.

CONCLUSIONS

Individuals with SAMCs benefit from integrated medical and substance abuse treatment, and such an approach can be cost-effective. These findings are relevant given the high prevalence and cost of medical conditions among substance abuse patients, new developments in medications for addiction, and recent legislation on parity of substance abuse with other medical benefits.

The origins of joint visual attention in infants

Two experiments examined the origins of joint visual attention with a training procedure. In Experiment 1, infants aged 6-11 months were tested for a gaze-following (joint visual attention) response under feedback and no feedback conditions. In Experiment 2, infants 8-9 months received feedback for either following the experimenter's gaze (natural group) or looking to the opposite side (unnatural group). Results of the 2 experiments indicate that (a) joint visual attention does not reliably appear prior to 10 months of age, (b) from about 8 months of age, a gaze-following response can be learned, and (c) simple learning is not sufficient as the mechanism through which joint attention cues acquire their signal value.

Protection against gram-negative bacteremia and endotoxemia with human monoclonal IgM antibodies

Hybridomas producing human monoclonal IgM antibodies (mAbs) against bacterial lipopolysaccharide (LPS) were generated by fusion of B lymphocytes from sensitized human spleen with heteromyeloma cells. The splenocytes were from patients undergoing splenectomy during staging for Hodgkin disease after vaccination with the J5 mutant of Escherichia coli, which is deficient in O antigenic side chains. This deficiency exposes the core oligosaccharide, common to LPS of all Gram-negative bacteria. The mAbs cross-reacted strongly with endotoxins from a wide range of unrelated species of Gram-negative bacteria. The mAbs also gave strong protection against LPS in the dermal Shwartzman reaction and against lethal Gram-negative bacteremia in mice. These findings indicate that monoclonal IgM against LPS endotoxin can neutralize its toxicity in vivo and might be valuable for treatment of patients with Gram-negative bacteremia. Analysis of one of the hybridoma clones, A6(H4C5), showed that the IgM mAb is directed against the covalently bound lipid A, which represents the most conservative and least variable structural element of LPS.

Attention and joint attention in preschool children with autism

Three experiments examined the role of attention in explaining dyadic (child-adult) and triadic (child-adult-object) joint attention difficulties in autism. Experiments 1 and 2 investigated children's ability to orient to an adult's attention bid and to follow the direction of a human or nonhuman cue. Experiment 3 tested ability to disengage and shift attention to objects. Results showed autism-specific difficulties at both dyadic and triadic levels. Children with autism were less responsive than developmentally delayed controls in orienting to attention bids and in following a human head-turn cue yet had no difficulty in shifting attention and were faster overall in orienting to targets. Results suggest a specific developmental delay in which children with autism rely on the presence of objects in the visual field to guide action. The relation between this problem and autistic children's difficulties with human communicative signals is discussed.

Multiple high risk HPV infections are common in cervical neoplasia and young women in a cervical screening population

AIMS

If human papillomavirus (HPV) testing is to be included within cervical screening programmes, the importance of multiple HPV infections in cervical neoplasia needs to be determined. This study investigated the diversity of multiple HPV types in a routine cervical screening population, and assessed associations with cervical neoplasia.

METHODS

Overall HPV prevalence, type specific prevalence, and extent of multiple infection were assessed in residual material from 3444 liquid based cytology samples, using real time GP5+/GP6+ polymerase chain reaction for screening and linear array assay for genotyping. HPV status was studied in relation to age and concurrent cytological evidence of dyskaryosis.

RESULTS

Twenty per cent of samples were HPV positive. HPV type diversity was broad, and multiple HPV infections occurred in half of the HPV positive samples. Younger women were significantly more likely to harbour multiple high risk HPV (HR-HPV) infections. Infections with multiple HR-HPV types were found in 3.4% of samples negative for neoplasia and in 33.3%, 41.8%, and 40.4% of samples with borderline, mild, or high grade dyskaryosis, respectively. Single HR-HPV infections were found in 4.9%, 38.6%, 45.0%, and 51.1% of negative, borderline, mild, or high grade dyskaryosis samples, respectively.

CONCLUSIONS

Multiple HR-HPV infections were most prevalent in young women. Multiple HR-HPV infections were not more frequent in high grade than in low grade cervical neoplasia, reflecting common sexual transmission of multiple HR-HPV. Prospective cohort studies linking sequential loss or gain of HPV types with cytological analysis are required to assess the impact of multiple HR-HPV infections on neoplastic progression.

Complications and management of implanted venous access catheters

A totally implanted subclavian venous access system composed of a reservoir and silastic catheter was employed in 92 patients receiving infusion chemotherapy and/or hyperalimentation. The major catheter complication was subclavian or jugular vein thrombosis observed in 15 patients (16%). Thrombosis was observed in the ipsilateral subclavian or jugular vein surrounding the catheter without restricting function, except in two patients with thrombosis in the vein at the end of the catheter. Prophylaxis with low-dose Coumadin was effective in preventing thrombosis in high-risk patients as defined by a history of prior thrombosis. Streptokinase and/or heparin relieved the signs and symptoms of thrombosis, but clot dissolution or reversal of collateral flow was not observed. Explantation of the catheter was not necessary in all patients in that embolic complications of the thrombosis were not observed, and the system was retained and functioned in five patients in spite of the presence of thrombosis around the catheter. Other complications of the implanted system include "pocket" infection, catheter migration, and occlusion. Most complications may be managed without obligate catheter removal.

Effect of four different oral contraceptives on various sex hormones and serum-binding globulins

In a double-blind, controlled, randomized, four-arm, bicentric clinical study, the effect of four oral contraceptives (OCs) on various hormone parameters and serum-binding globulins was investigated. Four groups with 25 volunteers each (18-35 years of age) were treated for six cycles with monophasic combinations containing 21 tablets with either 30 microg ethinylestradiol (EE) + 2 mg dienogest (DNG) (30EE/DNG), 20 microg EE + 2 mg DNG (20EE/DNG), 10 microg EE + 2 mg estradiol valerate (EV) + 2 mg DNG (EE/EV/DNG) or 20 microg EE + 100 microg levonorgestrel (LNG) (EE/LNG). The study was completed by 91 subjects. Blood samples were taken after at least 12 h of fasting on Day 21-26 of the preceding control cycle and on Day 18-21 of the first, third and sixth treatment cycle. The serum concentrations of free testosterone were significantly decreased by about 40-60% in all four groups, while those of dehydroepiandrosterone sulfate (DHEAS) showed a time-dependent decrease during treatment. Except for EE/EV/DNG, which increased prolactin significantly during the third and sixth cycles, no change was observed with the EE-containing preparations. There was a significant increase in the levels of serum-binding globulins during treatment, which differed according to the composition of the OCs used. The rise in sex hormone-binding globulin (SHBG) was highest during intake of 30EE/DNG (+320%) and lowest with EE/LNG (+80%), while the effect of 20EE/DNG and EE/EV/DNG was similar (+270%). The thyroxine-binding globulin (TBG) levels increased significantly, by 50-60%, during treatment with the DNG-containing formulations, while the effect of EE/LNG was less significant (+30%). The rise in corticosteroid-binding globulin (CBG), which occurred in all groups, was most pronounced in women treated with 30EE/DNG (+90%) and least with EE/EV/DNG (+55%), indicating a strong influence of EE and no effect of the progestogen component. In all treatment groups, the frequency of intracyclic bleeding rose in the first treatment cycle and decreased thereafter. Cycle control was significantly better with 30EE/DNG or EE/LNG than with 20EE/DNG or EE/EV/DNG. There was no significant change in blood pressure, body mass index or pulse rate throughout the study. In conclusion, the DNG-containing OCs caused a higher rise in SHBG and TBG levels than the LNG-containing preparation. The effects on CBG suggest a lesser hepatic effect of 2 mg EV as compared to 20 or 30 microg EE. In contrast to EE, the use of estradiol in OCs appeared to increase prolactin release, while the cycle control was better with the OC containing 30 microg EE.

Mitochondrial DNA in yeast and some mammalian species

Yeast DNA, in a cesium chloride density gradient, shows a minor or satellite band with a density lower than that of the main nuclear component. The DNA isolated from purified mitochondria of yeasts corresponds in density to this satellite band. In solution, this DNA more easily undergoes renaturation as compared to DNA from cell nuclei. The ease of this renaturation is presumably due to a homogeneity greater than that of nuclear DNA. Mitochondrial DNA isolated from several mammalian species has the same or higher density than nuclear DNA, but differs in its ready renaturability.

Regulation of the third member of the uncoupling protein family, UCP3, by cold and thyroid hormone

Uncoupling protein (UCP1) is a transmembrane proton transporter present in the mitochondria of brown adipose tissue (BAT), a specialized tissue which functions in temperature homeostasis and energy balance (Nicholls, D. G., and Locke, R. M. (1984) Physiol. Rev. 64, 2-40; Lowell, D. D., and Flier, J. S. (1997) Annu. Rev. Med.). UCP1 mediates the thermogenesis that is characteristic of BAT by uncoupling mitochondrial oxidation of substrates from ATP synthesis. Recently, two proteins related to UCP1 have been identified and designated UCP2 (Fleury, C., et al. (1997) Nature Genetics 15, 269-272) or UCP homolog (UCPH) (Gimeno, R. E., et al. (1997) Diabetes 46, 900-906) and UCP3 (Boss, O., et al. (1997) FEBS Lett. 408, 39-42; Vidal-Puig, A., et al. (1997) Biochem. Biophys. Res. Commun. 235, 79-82). We investigated the regulation in rats of UCP3, which is expressed primarily in skeletal muscle and BAT. Expression of rat UCP3 mRNA in BAT was upregulated by in vivo treatment with triiodothyronine (T3) and by exposure to cold, suggesting that UCP3 is active in thermogenesis and energy expenditure. In skeletal muscle, UCP3 mRNA was also upregulated by T3 but, surprisingly, not by cold exposure. A hypothesis is proposed to account for this differential regulation.

Influence of age on the response to Streptococcus pneumoniae vaccine in patients with recurrent infections and normal immunoglobulin concentrations

BACKGROUND

A deficient antibody response to polysaccharide antigens is determined by measuring the response to the 23-valent pneumococcal polysaccharide vaccine. However, the diagnosis of this specific antibody deficiency is hampered by the lack of sufficient data and standardized testing of the response to pneumococcal polysaccharides.

METHODS

All patients evaluated in our allergy/immunology clinic for recurrent respiratory infections between 1995 and 1997 without immunoglobulin, IgG subclass, or other known primary or secondary immunodeficiency were included in this analysis. IgG antipneumococcal serotypes 1, 3, 4, 6B, 9V, 14, 18C, 19F, and 23F were determined by a modified ELISA protocol. An adequate IgG antibody response to an individual serotype was arbitrarily defined as a postimmunization antibody titer of 1.3 microg/ml or greater or at least four times the baseline value.

RESULTS

A total of 113 patients fulfilling the criteria for inclusion in this analysis were divided into five age groups. The geometric means for preimmunization and postimmunization pneumococcal antibody titers for all serotypes increased with age. For post-immunization antibody concentrations, there was a sharp increase in the specific antibody concentrations in adults in comparison with all pediatric age groups ranging in age from 7 months to 16 years. Similarly, the number of serotypes to which there was an adequate response also increased with age.

CONCLUSION

We conclude that the definition of what constitutes an adequate response to pneumococcal immunization needs further definition. It is clear, however, that age has an important influence on the intensity of the response to most pneumococcal polysaccharides. Correlation studies between antibody concentrations in different IgG subclasses, functional studies, and protection studies against mucosal and invasive pneumococcal infections are in progress, and these should contribute to a refined definition of a normal response. The availability of a standardized method for the measurement of IgG antibodies against relevant pneumococcal serotypes is an important step toward this goal.

Thickness as prognostic aid in upper aerodigestive tract cancer

A retrospective review of records and microscopic slides was carried out on 151 patients, encompassing nine specific upper aerodigestive tract cancer sites, correlating depth of invasion with node metastases and outcome. In this preliminary descriptive study, thickness was found to be more closely related to node metastasis and to survival than was surface diameter in middle-stage tumors, particularly in tongue, floor of the mouth, buccal mucosa, gum, and soft palate sites. Thickness, depth of penetration, and bone involvement appear to represent the degree of general tumor aggressiveness better than does surface extent. A substitution of thickness measurement for surface diameter (T) in the present TNM staging system is suggested.

A human vascular disorder, supravalvular aortic stenosis, maps to chromosome 7

The pathogenesis of vascular disease is unclear, but genetic factors play an important role. In this study we performed linkage analyses in two families with supravalvular aortic stenosis, an inherited vascular disorder that causes narrowing of major arteries and may lead to cardiac overload and failure. DNA markers on the long arm of chromosome 7 (D7S371, D7S395, D7S448, and ELN) were linked to supravalvular aortic stenosis in both families with a combined logarithm of likelihood for linkage (lod score) of 5.9 at the ELN locus. These findings indicate that a gene for supravalvular aortic stenosis is located in the same chromosomal subunit as elastin, which becomes a candidate for the disease gene.