The mouse Peutz-Jeghers syndrome gene Lkb1 encodes a nuclear protein kinase

The protein kinase gene LKB1 has recently been identified as the gene mutated in the Peutz-Jeghers cancer predisposition syndrome. This condition is characterized by inherited susceptibility to a range of cancers but in particular those of the gastrointestinal tract. Here we have characterized the mouse Lkb1 gene. The mouse Lkb1 gene consists of 10 exons covering approximately 15 kb in length, maps to mouse chromosome 10 and encodes a protein showing strong sequence similarity to human LKB1. The 3" end of Lkb1 in the mouse is in very close proximity to the 3" end of an apparently unrelated gene R29144/1 and it seems probable that overlapping transcripts of the two genes are produced. Using transfection of Lkb1 cDNAs we have shown that Lkb1 is most likely a nuclear protein and have defined a nuclear localization signal within the protein sequence. Thus the defect in Peutz-Jeghers syndrome may directly result in changes in gene expression in the nucleus of target cells.

Novel chromosome 16 abnormality--der(16)del(16) (q13)t(16;21)(p11.2;q22)--associated with acute myeloid leukemia

Inversion of chromosome 16 is a common feature of acute myeloid leukemia (AML) M4, while t(16;21), although also associated with AML, appears to be a separate entity. We present a patient with myelodysplastic syndrome (MDS) who transformed to AML-M1. The karyotype was normal at diagnosis; at 15 months, hematological evidence of transformation was present, and repeat cytogenetics showed a novel rearrangement of one chromosome 16. Two breaks had occurred; one in the short arm at 16p11, with translocation of the segment distal to this onto chromosome 21q, and the other in the long arm at 16q22 with subsequent deletion of the segment from 16q22-->qter. Fluorescence in situ hybridization (FISH) confirmed the abnormalities detected by cytogenetics and excluded involvement of the AML1 gene on 21q22. While the 16q22 breakpoint was at the usual site for the inv(16), the 16p11 was not. The patient is more characteristic of t(16;21) than inv(16), and adds to the spectrum of chromosome 16 abnormalities in AML.

Deafferentation induced changes in GAD67 and GluR2 mRNA expression in mouse somatosensory cortex

Partial vibrissectomy in adult mice induces body map plasticity in SI barrel cortex. To examine if the disturbed balance of cortical activation affects the excitatory and inhibitory neurotransmitter systems, we studied glutamic acid decarboxylase (GAD 67) and AMPA receptor subunit GluR2 mRNA expression in the barrel cortex. At varying times post-vibrissectomy, sparing row C of whiskers on one side of the snout, the brains were processed for in situ hybridization using specific [(35)S]oligonucleotides to detect the laminar localization of GAD67 and GluR2 mRNAs. Three and seven days after vibrissectomy, the expression of GAD67 was decreased in the deafferented cortex, while 30 days post-lesion, no effects were observed. At 3 days post-lesion, an ipsilateral decrease in GAD67 mRNA expression was also observed. No decreases in GluR2 transcripts were found in the deafferented cortex, but an increased expression was observed in the representation of the spared row C of whiskers 3 days after vibrissectomy. Seven and 30 days post lesion no changes in GluR2 expression were found. These data indicate that in the barrel cortex, peripheral deafferentation transiently regulates GAD67 and GluR2 expression at the transcriptional level. We suggest that this may be a manifestation of adaptive processes.

An evaluation of international nursing education using interactive desktop video conferencing

Evolving computer technology has opened the door to unique and previously unavailable educational experiences. The use of one form of distance learning enabled undergraduate nursing students in the United States and England to participate in a short course on women's health issues. The nursing faculty at two universities, one in the United States and the other in England, collaborated on an international nursing education project. The delivery device was interactive desktop video conferencing (DTV). The focus of this article is on the evaluation of the project with recommendations about how best to use DTV in international nursing education.

Osteoarthritis-susceptibility locus on chromosome 11q, detected by linkage

We present a two-stage genomewide scan for osteoarthritis-susceptibility loci, using 481 families that each contain at least one affected sibling pair. The first stage, with 272 microsatellite markers and 297 families, involved a sparse map covering 23 chromosomes at intervals of approximately 15 cM. Sixteen markers that showed evidence of linkage at nominal P</=.05 were then taken through to the second stage, with an additional 184 families. This second stage confirmed evidence of linkage for markers on chromosome 11q. Additional markers from this region were then typed to create a denser map. We obtained a maximum single-point LOD score, at D11S901, of 2.40 (P=.0004) and a maximum multipoint-LOD score of 3.15, between markers D11S1358 and D11S35. A subset of 196 of the 481 families, comprising affected female sibling pairs, generated a corrected LOD score of 2.54 (P=.0003) for marker D11S901, with evidence for linkage extending 12 cM proximal to this marker. When we stratified for affected male sibling pairs there was no evidence of linkage to chromosome 11. Our data suggest that a female-specific susceptibility gene for idiopathic osteoarthritis is located on chromosome 11q.

Microchimerism of maternal origin persists into adult life

Recent studies indicate that fetal cells persist in maternal blood for decades after pregnancy. Maternal cells are known to engraft and persist in infants with immunodeficiency, but whether maternal cells persist long-term in immunocompetent offspring has not specifically been investigated. We developed sensitive human leukocyte antigen-specific (HLA-specific) PCR assays and targeted nonshared maternal HLA genes to test for persistent maternal microchimerism in subjects with scleroderma and in healthy normal subjects. Nonshared maternal-specific DNA was found in 6 of 9 scleroderma patients. In situ hybridization with double labeling for X and Y chromosome-specific sequences revealed female cells in peripheral blood samples from 2 male scleroderma patients. HLA-specific PCR also frequently revealed persistent maternal microchimerism in healthy control subjects. The mean age of all subjects with maternal microchimerism was 28 years (range: 9-49 years). With few exceptions, mothers of subjects with persistent maternal microchimerism were HLA incompatible with subjects for class I and class II alleles. These results clearly indicate that HLA-disparate maternal cells can persist in immunocompetent offspring well into adult life. The biological significance of maternal microchimerism and whether it might contribute to autoimmune disease requires further investigation.

Solvent influence on spray-dried biodegradable microspheres

Microspheres of fixed poly(D,L-lactic acid) (PDLLA) composition--Resomer R104:R202H (30:70)--containing 20% w/w rifampicin have been spray-dried from a range of acetonic, halogenated, and solvent mixtures thereof under constant process conditions to examine the influence of solvent selection on microsphere characteristics. Solubility of the polymer composite in the studied solvents determined the kinetics of polymer deposition during drying. Viscosity studies provided an indirect index of solvent power in ascending order: acetone (ACT) < dichloromethane (DCM) < chloroform (CFM) < halothane (HAL). Accordingly, poorer acetonic solvents produced a more open, porous matrix of increased mean diameter, whereas DCM, CFM and HAL generated more coherent matrices of greater density and elevated glass transition temperature, which significantly retarded drug release. Yield generally increased in parallel with solvent strength and microsphere density consistent with the proposed generalized particle formation mechanism. Residual solvent also increased with particle density, both parameters being interrelated and dictated by the inherent affinity of the polymer composite for individual solvents. In turn, the position of glass transition temperature (Tg) and the quantity of associated polymer stress-relaxation were a direct function of amount and persistence of organic residue. The magnitude of these changes determined the relative rates and extents of microsphere ageing, as measured by drug release studies. In general, rate of drug release increased with Tg, after corrections were made for specific surface area (r2 = 0.963). Overall, solvent choice for spray-drying has a remarkable influence on microsphere characteristics and, accordingly, technological as well as toxicological considerations should be paid during selection of same.

A model of in vivo human venous thrombosis that confirms changes in the release of specific soluble cell adhesion molecules in experimental venous thrombogenesis

PURPOSE

The mechanisms of venous thrombogenesis have been studied by using animal models and cells in culture. The results from these systems may not, however, be relevant to the human condition. The aim of this study was to develop a method by which thrombus could be safely produced in a human vein in vivo. The model that was developed was used as a means of studying the changes in soluble adhesion molecule expression in human venous thrombogenesis.

METHODS

An autologous thrombin extract was used to generate experimental thrombi in the disconnected portion of the long saphenous veins of 30 patients who were undergoing routine bilateral varicose vein surgery. The contralateral vein was perfused with thrombin extract diluent buffer to act as the control. The concentration of soluble P-, E- and L-selectin, intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule-1 were measured by means of specific enzyme-linked immunosorbent assays in samples of blood taken from veins in which thrombus had formed and in contralateral control veins.

RESULTS

Thrombosis invariably formed when at least 100 IU of thrombin activity was administered. Thrombus formation was independent of the time that the thrombin extract was allowed to remain within the emptied vessel. Thrombosis never developed in control vessels that were similarly treated with the buffer used to dilute the thrombin extract. Experimental thrombi were composed mainly of red cells, with layers of fibrin next to platelet and leukocyte packages. These findings are similar to those observed in samples of established human venous thrombi. There were small but significantly higher levels of the adhesion molecules, soluble P-selectin, and vascular cell adhesion molecule-1 in blood taken from veins in which experimental thrombi had formed, compared with controls (P =.015 and.007, respectively; Wilcoxon signed rank test). Serum levels of soluble L-selectin, E-selectin, and ICAM-1 were not affected by thrombosis.

CONCLUSION

This model is safe and reproducible. It produces thrombi with a morphology similar to that described for established human deep venous thrombi. The model may be appropriate for the study of the early changes that occur during human venous thrombogenesis and may also be of value in testing the efficacy of novel antithrombotic agents.

A calorimetric investigation into the interaction between paracetamol and polyethlene glycol 4000 in physical mixes and solid dispersions

The solubility, heat of solution and dissolution rate of paracetamol and polyethyelene glycol 4000 (PEG 4000) systems have been studied in order to clarify the nature of the interaction between the two components during dissolution of solid dispersions. The logarithmic solubility of paracetamol demonstrated a non-linear increase with concentration of PEG 4000, while linear relationships between heat of solution in water and concentration were seen for both individual components. However, the heat of solution of paracetamol was found to decrease with increasing concentrations of PEG 4000. Similarly, the heats of solution in water of physical mixes and solid dispersions prepared using two manufacturing protocols were found to be lower than the theoretical values calculated from those corresponding to the individual components. Drug release studies showed a marked increase in paracetamol dissolution rate when prepared as a solid dispersion, with behaviour consistent with carrier controlled dissolution observed at low drug contents which was ascribed to enhanced dissolution of the drug into the diffusion layer of the PEG 4000. The implications of the understanding of this mechanism for the choice of carrier and manufacturing protocol for solid dispersion products is discussed.

JNK activation is not required for Fas-mediated apoptosis

Fas ligation in the presence of cycloheximide induced Jun N-terminal kinase 1 (JNK1) and JNK2 phosphorylation, caspase activation and cell death in the IL-3-dependent cell line BAF3. Fas-mediated apoptosis was prevented by expression of dominant negative FADD but not inhibited by IL-3. To investigate the role of JNK activation in this process, we examined cells over-expressing a JNK-specific phosphatase M3/6. M3/6 prevented Fas stimulation of JNK, but did not affect Fas-mediated caspase activation or cell death, demonstrating that JNK activation is not required for these processes.

14 years of follow-up from the Edinburgh randomised trial of breast-cancer screening

BACKGROUND

The Edinburgh randomised trial of breast-cancer screening recruited women aged 45-64 years from 1978 to 1981 (cohort 1), and those aged 45-49 years during 1982-85 (cohorts 2 and 3). Results based on 14 years of follow-up and 270,000 woman-years of observation are reported.

METHODS

Breast-cancer mortality rates in the intervention group (28,628 women offered screening) were compared with those in the control group (26,026) with adjustment for socioeconomic status (SES) of general medical practices. Rate ratios were derived by means of logistic regression for the total trial population and for women first offered screening while younger than 50 years. Analyses were by intention to treat.

FINDINGS

Initial unadjusted results showed a difference of just 13% in breast-cancer mortality rates between the intervention and control groups (156 deaths [5.18 per 10,000] vs 167 [6.04 per 10,000]; rate ratio 0.87 [95% CI 0.70-1.06]), but the results were influenced by differences in SES by trial group. After adjustment for SES, the rate ratio was 0.79 (95% CI 0.60-1.02). When deaths after diagnosis more than 3 years after the end of the study were censored the rate ratio became 0.71 (0.53-0.95). There was no evidence of heterogeneity by age at entry and no evidence that younger entrants had smaller or delayed benefit (rate ratio 0.70 [0.41-1.20]). No breast-cancer mortality benefit was observed for women whose breast cancers were diagnosed when they were younger than 50 years. Other-cause mortality rates did not differ by trial group when adjusted for SES.

INTERPRETATION

Our findings confirm results from randomised trials in Sweden and the USA that screening for breast cancer lowers breast-cancer mortality. Similar results are reported by the UK geographical comparison, UK Trial of Early Detection of Breast Cancer. The results for younger women suggest benefit from introduction of screening before 50 years of age.

Development and phonetic differentiation of speech movement patterns

It is often hypothesized that speech production units are less distinctive in young children and that generalized movement primitives, or templates, serve as a base on which distinctive, mature templates are later elaborated. This hypothesis was examined by analyzing the shape and stability of single close-open speech movements of the lower lip recorded in 4-year-old, 7-year-old, and adult speakers during production of utterances that varied in only a single phoneme. To assess the presence of a generalized template, lower lip movement sequences were time and amplitude normalized, and a pattern recognition procedure was implemented. The findings indicate that speech movements of children already converged on phonetically distinctive patterns by 4 years of age. In contrast, an index of spatiotemporal stability demonstrated that the stability of underlying patterning of the movement sequence improves with maturation.

Suppression of SHP-2 and ERK signalling promotes self-renewal of mouse embryonic stem cells

The propagation of pluripotent mouse embryonic stem (ES) cells depends on signals transduced through the cytokine receptor subunit gp130. Signalling molecules activated downstream of gp130 in ES cells include STAT3, the protein tyrosine phosphatase SHP-2, and the mitogen-activated protein kinases, ERK1 and ERK2. A chimaeric receptor in which tyrosine 118 in the gp130 cytoplasmic domain was mutated did not engage SHP-2 and failed to activate ERKs. However, this receptor did support ES cell self-renewal. In fact, stem cell colonies formed at 100-fold lower concentrations of cytokine than the unmodified receptor. Moreover, altered ES cell morphology and growth were observed at high cytokine concentrations. These indications of deregulated signalling in the absence of tyrosine 118 were substantiated by sustained activation of STAT3. Confirmation that ERK activation is not required for self-renewal was obtained by propagation of pluripotent ES cells in the presence of the MEK inhibitor PD098059. In fact, the growth of undifferentiated ES cells was enhanced by culture in PD098059. Thus activation of ERKs appears actively to impair self-renewal. These data imply that the self-renewal signal from gp130 is a finely tuned balance of positive and negative effectors.

The tetrodotoxin-resistant sodium channel SNS has a specialized function in pain pathways

Many damage-sensing neurons express tetrodotoxin (TTX)-resistant voltage-gated sodium channels. Here we examined the role of the sensory-neuron-specific (SNS) TTX-resistant sodium channel alpha subunit in nociception and pain by constructing sns-null mutant mice. These mice expressed only TTX-sensitive sodium currents on step depolarizations from normal resting potentials, showing that all slow TTX-resistant currents are encoded by the sns gene. Null mutants were viable, fertile and apparently normal, although lowered thresholds of electrical activation of C-fibers and increased current densities of TTX-sensitive channels demonstrated compensatory upregulation of TTX-sensitive currents in sensory neurons. Behavioral studies demonstrated a pronounced analgesia to noxious mechanical stimuli, small deficits in noxious thermoreception and delayed development of inflammatory hyperalgesia. These data show that SNS is involved in pain pathways and suggest that blockade of SNS expression or function may produce analgesia without side effects.

Sleep and behavior problems among preschoolers

This study described the relationship between amount of sleep and behavior problems among preschoolers. Participants were 510 children aged 2 to 5 years who were enrolled through 68 private pediatric practices. Parents reported on the amount of sleep their child obtained at night and in 24-hour periods. With demographic variables controlled, regression models were used to determine whether sleep was associated with behavior problems. The relationship between less sleep at night and the presence of a DSM-III-R psychiatric diagnosis was significant (odds ratio = 1.23, p = .026). Less night sleep (p < .0001) and less sleep in a 24-hour period (p < .004) were associated with increased total behavior problems on the Child Behavior Checklist; less night sleep (p < .0002) and less 24-hour sleep (p < .004) were also associated with more externalizing problems on that measure. Further research is needed to ascertain whether sleep is playing a causal role in the increase of behavior problems.

Syndromal obesity due to paternal duplication 6(q24.3-q27)

The likelihood of a paternally expressing imprinted gene in chromosome region 6(q23-24) has been highlighted by cases of transient neonatal diabetes mellitus (TNDM) in which paternal uniparental disomy (UPD) for chromosome 6 or paternal duplication 6(q23-qter) was detected. We present the case of a 38-year-old man with moderate to severe intellectual delay, short stature, small hands and feet, eye abnormality, small mouth, and obesity (without hyperphagia) beginning in mid-childhood. The perinatal and neonatal histories were normal. The patient had a duplication within 6q. Fluorescence in situ hybrisation studies were performed with single and dual hybridisations using a chromosome 6 library probe, short and long arm subregional probes, 6q23-24, 6q25.3-6qter locus-specific probes, and a 6q telomere probe. The hybridisation results defined an inverted duplication of 6q24.3 to 6q27. DNA studies with microsatellite markers from 6p and 6q showed regular biparental inheritance of chromosome 6 and confirmed that the duplication was paternal in origin. Our patient appears to be the first one known to have paternal duplication of chromosome area 6(q24-q27) who did not have TNDM as an infant. He has remained nondiabetic, although obesity, without hyperphagia, has been a constant problem since its onset in mid-childhood.

A radiation hybrid map of the rat genome containing 5,255 markers

A whole-genome radiation hybrid (RH) panel was used to construct a high-resolution map of the rat genome based on microsatellite and gene markers. These include 3,019 new microsatellite markers described here for the first time and 1,714 microsatellite markers with known genetic locations, allowing comparison and integration of maps from different sources. A robust RH framework map containing 1,030 positions ordered with odds of at least 1,000:1 has been defined as a tool for mapping these markers, and for future RH mapping in the rat. More than 500 genes which have been mapped in mouse and/or human were localized with respect to the rat RH framework, allowing the construction of detailed rat-mouse and rat-human comparative maps and illustrating the power of the RH approach for comparative mapping.

Modulation of rifampicin release from spray-dried microspheres using combinations of poly-(DL-lactide)

Microspheres containing 20% w/w rifampicin (RIF) with smooth morphology have been readily prepared from combinations of low, R104 (Mw, 2000) and moderate, R202H (Mw, 9000), molecular weight poly(D,L-lactide) (PDLLA) as a means to modulate drug release from either polymer when used alone. These have been characterized with respect to their drug loading, granulometry, in vitro drug release and thermal behaviour. Particle size distributions were Gaussian, whereby mean microsphere diameter was found to increase from 2.11 to 2.98 microns as the proportion of more viscous R202H increased, whilst > 95% of particles were < 10 microns, irrespective of the polymer blend used. Use of a reduced inlet temperature for spray-drying gave uncharacteristically high production yields in the range of 55.8-80.7% for the process. Encapsulation efficiencies were quantitative with the weight proportion of drug co-dissolved (p < 0.05), yielding microspheres of high and predictable RIF loading. In vitro drug release revealed a dramatic shift in release profile between 40 and 60% R104. Closer examination in this range showed the predicted pattern of increased release rate as the fraction of more hydrophilic R104 increased. However, disproportionate differences were evident between 44 and 48% R104. From the apparent temperature dependent drug release, the criticality of matrix composition was attributed to the coincidence of matrix softening with the dissolution medium temperature and consequent hydration, which, at a finite composition, resulted in a controlled auto-hydration mechanism. Dramatic dependence of release rate with dissolution methodology was accountable to the fact that drug release was considerably quicker where microspheres remained suspended and individualized with the USP paddle method as opposed to aggregated with the shaking bath methodology. In conclusion, the utility of blending racemic PDLLA to modulate drug release and the convenience of spray-drying as a technique to produce microspheres of predictable character have been demonstrated. The temperature-dependent release exhibited may have application in the site-specific delivery of drugs where local increased biochemical activity promotes drug release in response to an increased pharmacological need.

Synechococcus mutants resistant to an enamine mechanism inhibitor of glutamate-1-semialdehyde aminotransferase

An enamine mechanism-based inactivator of mammalian delta-aminobutyric acid aminotransferase, 4-amino 5-fluoropentanoic acid is a potent inhibitor of cell growth and pigment formation in the cyanobacterium Synechococcus PCC 6301. It was demonstrated that 4-amino 5-fluoropentanoic acid inhibits the aminolaevulinate synthesis at glutamate 1-semialdehyde aminotransferase and that in the mutant obtained by exposing cells to 40 microM 4-amino 5-fluoropentanoic acid, this enzyme was insensitive to the inhibitor. The specific activity of glutamate 1-semialdehyde aminotransferase in cell extracts was lower in the mutant, although the cell growth rate was unaffected. The decrease in sensitivity to 4-amino 5-fluoropentanoic acid in the mutant is due to a structural gene mutation, a single base change in the hemL gene resulting in a S162T substitution in the gene product.

Duplication within chromosome 5q characterized by fluorescence in situ hybridization

We present a 16-month-old boy with developmental delay, minor anomalies, small penis, and lymphedema of the upper limbs. Routine cytogenetic analysis suspected a duplication of 5q. Fluorescent in situ hybridization (FISH) with a cosmid probe (MCC at the 5q22 APC region) showed tandemly duplicated fluorescent signals on one of chromosomes 5, whereas FISH with three YAC probes (TYAC12 at 5q35, HTY3182 at 5q34, and TYAC139 at 5q31) did not give duplicated signals. These findings indicate a duplication of 5q22 band in one chromosome 5. The boy we describe here is the first case of a pure partial duplication of 5q to be proven by FISH techniques. A review of previously reported cases of putative partial 5q duplication showed no consistent phenotype.

Barriers to the use of a diagnostic oral microbiology laboratory by general dental practitioners

OBJECTIVE

To identify barriers on the use of diagnostic microbiology facilities in general dental practice.

DESIGN

A cross-sectional survey using a postal questionnaire.

SETTING

Primary/secondary care interface between the diagnostic oral microbiology laboratory, University of Glasgow Dental Hospital and School, Glasgow and dental practitioners within the surrounding health boards, 1998.

SUBJECTS

All GDPs (797) within Argyll and Clyde, Ayrshire and Arran, Lanarkshire and Greater Glasgow Health Boards.

MAIN OUTCOME MEASURES

The responses were expressed as both absolute and relative frequencies.

RESULTS

Responses were received from 430 (55%). The most frequent reason for failure to use the service was lack of information, with more than half of the respondents claiming to be unaware of the facility. Lack of request forms and sampling equipment were also viewed as barriers to using the service.

CONCLUSIONS

The laboratory is failing to successfully communicate its role in addressing the growing burden of antibiotic resistance in the community and must be more proactive in encouraging appropriate use and increasing accessibility of the service to GDPs.

Type 2 diabetes mellitus in Navajo adolescents

Diabetes mellitus afflicts over one-fifth of the Navajo population aged over 20 years, but the prevalence of diabetes in Navajo adolescents is unclear. We conducted voluntary testing for diabetes mellitus at two high schools on the Navajo reservation to clarify the prevalence as well as to assess the utility of a high-school based screening program. Body mass index measurements (BMI), oral glucose tolerance tests, and hemoglobin A1C measurements were obtained in consenting high school students. Of the 276 students that participated, 234 were Navajo. Only one Navajo student (0.4%) had diabetes mellitus, although eight (3%) had impaired glucose tolerance or impaired fasting glucose. Participant BMI did not differ significantly from nonparticipant BMI. No correlation existed between BMI or impaired glucose handling, and significant overlap existed between the hemoglobin A1C values of students with impaired glucose handling and students without impaired glucose handling. Increased participation in screening programs may reveal higher disease prevalence, but high school-based screening is not justified by this study, despite the high rates of diabetes mellitus in the Navajo population.

The melanocyte stimulating hormone receptor polymorphism: association of the V92M and A294H alleles with basal cell carcinoma

Allelic variants in the melanocyte stimulating hormone receptor (MC1R) gene are susceptibility/outcome candidates for cutaneous basal cell carcinoma (BCC). We identified the val92met (V92M) and asp294his (A294H) alleles in 311 cases and 190 controls. The cases included four homo- and 53 heterozygotes for V92M and 12 heterozygotes for A294H and two compound heterozygotes (V92M/A294H). Allele frequencies were similar in controls. In the cases, we found no association between the alleles and skin type though A294H was more common in those with red hair (4/19) than with other hair colours (6/163) (P = 0.012). V92M was not associated with BCC numbers. Cases with A294H had fewer BCC in comparison with those without the allele though the difference was not significant. After inclusion of red hair in the model, A294H was significantly associated with fewer tumours. While MCIR alleles are attractive candidates for BCC, the variants studied did not influence susceptibility. The association with outcome was relatively weak. The large number of MC1R alleles and their low frequency, make assessment of the importance of this gene in the pathogenesis of skin cancers difficult.