Lighter Skin Types Research Articles

Pigment phenotype and biogeographical ancestry from ancient skeletal remains: inferences from multiplexed autosomal SNP analysis

In the present study, a multiplexed genotyping assay for ten single nucleotide polymorphisms (SNPs) located within six pigmentation candidate genes was developed on modern biological samples and applied to DNA retrieved from 25 archeological human remains from southern central Siberia dating from the Bronze and Iron Ages. SNP genotyping was successful for the majority of ancient samples and revealed that most probably had typical European pigment features, i.e., blue or green eye color, light hair color and skin type, and were likely of European individual ancestry. To our knowledge, this study reports for the first time the multiplexed typing of autosomal SNPs on aged and degraded DNA. By providing valuable information on pigment traits of an individual and allowing individual biogeographical ancestry estimation, autosomal SNP typing can improve ancient DNA studies and aid human identification in some forensic casework situations when used to complement conventional molecular markers.

Risk Factors in Elderly People for Lentigo Maligna Compared With Other Melanomas

To assess lentigo maligna (LM) as an epidemiological entity separate from other melanomas (OMs) in elderly people. Double age- and sex-matched case-control study to compare the risk factors for LMs and OMs. General community. Patients A total of 76 patients with LM were paired by age and sex with 76 patients with OMs and 152 controls. The association of melanoma risk with the following potential risk factors: sun exposure history by 10-year periods, frequency of sunburns, phenotypic traits, density of freckles and sun sensitivity at age 20 years, counts of nevi larger than 2 mm in diameter on the face and forearm, skin aging features (as assessed using a photographic scale), and history of basal and/or squamous cell carcinomas. Risk of LMs and OMs were similarly associated with history of sunburns, light skin type, and freckling. Cumulative chronic outdoor and occupational sun exposures were not risk factors in any of the 2 groups of melanomas. Lentigo maligna differed from OMs by the absence of a detectable association with the number of nevi and a greater association with nonmelanoma skin cancers. Although chronically sun-exposed skin is a prerequisite for LM, risk of LM does not increase with the cumulative dose of sun exposure, but LM is associated with sunburn history, like all other types of melanomas. The main epidemiological characteristic of LM is the absence of an apparent relation with the genetic propensity to develop nevi. This epidemiological profile is in accordance with recent molecular findings and may also account for the histoclinical and evolutive characteristics of LM.

Glycolic Acid Peels Versus Salicylic–Mandelic Acid Peels in Active Acne Vulgaris and Post-Acne Scarring and Hyperpigmentation

BACKGROUND Many clinicians have used glycolic acid (GA) peels for facial acne, scarring, and hyperpigmentation, mainly in lighter skin types. Salicylic–mandelic acid combination peels (SMPs) are a newer modality, and there have been no well-controlled studies comparing them with other conventional agents. OBJECTIVE To compare the therapeutic efficacy and tolerability of 35% GA peels and 20% salicylic–10% mandelic acid peels in active acne and post-acne scarring and hyperpigmentation. METHODS AND MATERIALS Forty-four patients with facial acne and post-acne scarring and hyperpigmentation were divided into two groups, with one receiving GA peels and the other SMPs at fortnightly intervals for six sessions. The treating physician performed objective evaluation of treatment outcomes. The patients, the treating physician, and an independent observer made subjective assessments. Side effects of both agents were also noted. RESULTS Both the agents were effective, but SMPs had a higher efficacy for most active acne lesions (p<.001) and hyperpigmentation (p<.001). Side effects were also lesser with SMPs. CONCLUSION Both the agents were effective and safe in Indian patients, with SMPs being better for active acne and post-acne hyperpigmentation.

Glycolic Acid Peels Versus Salicylic-Mandelic Acid Peels in Active Acne Vulgaris and Post-Acne Scarring and Hyperpigmentation: A Comparative Study

Many clinicians have used glycolic acid (GA) peels for facial acne, scarring, and hyperpigmentation, mainly in lighter skin types. Salicylic-mandelic acid combination peels (SMPs) are a newer modality, and there have been no well-controlled studies comparing them with other conventional agents. To compare the therapeutic efficacy and tolerability of 35% GA peels and 20% salicylic-10% mandelic acid peels in active acne and post-acne scarring and hyperpigmentation. Forty-four patients with facial acne and post-acne scarring and hyperpigmentation were divided into two groups, with one receiving GA peels and the other SMPs at fortnightly intervals for six sessions. The treating physician performed objective evaluation of treatment outcomes. The patients, the treating physician, and an independent observer made subjective assessments. Side effects of both agents were also noted. Both the agents were effective, but SMPs had a higher efficacy for most active acne lesions (p<.001) and hyperpigmentation (p<.001). Side effects were also lesser with SMPs. Both the agents were effective and safe in Indian patients, with SMPs being better for active acne and post-acne hyperpigmentation.

Nonablative fractional resurfacing in the male patient

Skin resurfacing can be divided into nonablative, nonablative fractional, ablative fractional, and traditional ablative categories. Nonablative technologies have yielded inconsistent and unimpressive results, whereas ablative technologies, although generally clinically effective, are losing momentum as a result of prolonged recovery times, risks for hypopigmentation, limitation in lighter skin types, and the production of unnatural sheen and texture to the skin. Fractional resurfacing can produce the safety of nonablative technologies and the efficacy of traditional ablative resurfacing. Nonablative fractional resurfacing is the most widely studied of fractional technologies allowing for nonablative tissue coagulation, creation of microthermal zones, and resurfacing with extrusion and replacement of damaged tissue with rapid re-epithelialization. This article will review nonablative fractional resurfacing with 1550-nm laser in the male patient.

Keratotic Skin Lesions and Other Risk Factors Are Associated with Skin Cancer in Organ-Transplant Recipients: A Case–Control Study in The Netherlands, United Kingdom, Germany, France, and Italy

This study examines the association of keratotic skin lesions with the development of skin cancer in 915 solid organ-transplant recipients in five European countries. In a hospital-based case-control study, cases with squamous- and basal-cell carcinoma were compared with controls without skin cancer. Questionnaires, scrutiny of medical charts, and skin examination were delivered according to a standardized protocol. Keratotic skin lesions and viral warts were counted on different body sites. Keratotic skin lesions were strongly associated with an increased risk of squamous-cell carcinoma, with adjusted odds ratios of 4.1 (2.4;7.0) and 12.1 (6.1;24) for 1-49 and 50 and more keratotic skin lesions compared with no lesions, respectively. Keratotic skin lesions were also associated with basal-cell carcinoma with adjusted odds ratios of 2.9 (1.7;4.9) and 4.0 (1.7;9.2) for 1-49 and 50 and more lesions, respectively. Lighter skin types and painful sunburns were also significantly associated with an increased risk of squamous- and basal-cell carcinoma. Keratotic skin lesions are strongly associated with skin cancer and are, thus, an important clinical criterion for identifying those organ-transplant recipients at an increased risk of skin cancers who should be offered more intensive skin surveillance.

Treatment of vitiligo vulgaris with narrow‐band UVB and oral Polypodium leucotomos extract: a randomized double‐blind placebo‐controlled study

The first choice treatment for vitiligo vulgaris is narrow-band UVB (NB-UVB), but no satisfactory treatment exists. To investigate if Polypodium leucotomos, an antioxidative and immunomodulatory plant extract, improves NB-UVB-induced repigmentation. Fifty patients with vitiligo vulgaris randomly received 250 mg oral P. leucotomos or placebo three times daily, combined with NB-UVB twice weekly for 25-26 weeks. Repigmentation was higher in the P. leucotomos group vs. placebo in the head and neck area (44% vs. 27%, P = 0.06). Small repigmentation increases (P = n.s.) were observed for the trunk (6% increased repigmentation), extremities (4%), and hands and feet (5%) in the P. leucotomos group vs. placebo. Patients attending more than 80% of required NB-UVB sessions showed increased repigmentation in the head and neck area in the P. leucotomos group vs. placebo (50% vs. 19%, P < 0.002); no significant differences were seen in the other body areas. Patients with skin types 2 and 3 showed more repigmentation in the head and neck area in the P. leucotomos group vs. placebo (47% vs. 21%, P = 0.01), and no significant differences were seen in the other body areas. No conclusions could be drawn on skin types 4 and 5 due to low patient numbers. There is a clear trend towards an increase in repigmentation of vitiligo vulgaris affecting the head and neck area when NB-UVB phototherapy is combined with oral P. leucotomos. This effect may be more pronounced in light skin types.

Malignes Melanom

In Germany, 6100 women and 5300 men contract a malignant melanoma of the skin every year. The chances of being cured are good in the early stages of the disease, but the average survival following distant metastasis is only 6 to 9 months. Therefore, early diagnosis is crucial, particularly as the skin is, by nature, a readily accessible organ. The introduction of epiluminescence microscopy has increased diagnostic accuracy significantly. In cases of doubt, complete excision of the suspect pigmented lesion is always advisable. A light skin type, presence of numerous naevi, genetic predisposition (familial history) and increased UV exposure are considered as risk factors. As a rule, adjuvant imunotherapy with interferon-alphais recommended in high-risk patients. A multidisciplinary approach consisting of surgery, radiotherapy, chemotherapy and immunotherapy has proved beneficial in advanced stages of metastasis.

Influence of UV exposure on DNA damage in Chinese skin

Influence of UV exposure on DNA damage in Chinese skin

Clinical potential of Melanotan® (NDP‐α‐MSH) in skin protection – current status and future perspective

There is good epidemiological evidence that melanin in the skin protects against sunburn and skin cancer resulting from excessive ultraviolet radiation (UVR) exposure. Melanin is synthesized in a multistep biochemical pathway within specialized cell types in human skin called melanocytes situated in the epidermis. UV light causes an increase in melanocyte‐stimulating hormone (α‐MSH) receptor activity on cutaneous melanocytes (MC1‐R) that results in an increase of eumelanin within the epidermal melanocytes. Melanotan is a synthetic analogue of α‐MSH with potent melanogenic activity in animals and humans. We have recently completed a double‐blind, randomized controlled study in 80 healthy Caucasian adult subjects. A fixed dose of Melanotan (0.16 mg/kg/day) or placebo in a 3 : 1 ratio was given as three cycles of daily subcutaneous injections over 10 days each month for three consecutive months. Changes in skin pigmentation were quantified by serial skin reflectance measurements and UVR injury, as determined by ×3 MED exposure to broadband UVR, was assessed by measurement of apoptosis (sunburn cells). Results demonstrated that a highly significant increase in skin melanin was attained in all subjects on active treatment compared with placebo, and this was especially pronounced in subjects with lighter skin types (Fitzpatrick I and II; P &lt; 0.0001). In these latter subjects, significant sunburn protection was also determined. The ability of Melanotan to stimulate melanin production without the associated UV‐induced skin damage may prove a useful adjunct to current photoprotective strategies to stem the marked rise in skin cancer incidence. Currently, we are studying the therapeutic efficacy of a slow‐release implant of Melanotan in skin disorders such as polymorphic light eruption and psoriasis.

The use of pulsed dye laser for the prevention and treatment of hypertrophic scars in chinese persons.

Pulse dye laser has been used with variable degrees of success in the treatment of hypertrophic scars, and although earlier reports suggested a significant degree of improvement, more recent studies have raised concern about its effectiveness. Furthermore, most previous studies examined its use in patients with light skin types, and the use of pulse dye laser in dark-skinned patients for the treatment of hypertrophic scars is not well established. The objective was to assess the role of pulsed dye laser therapy in the treatment and prevention of hypertrophic scars in Chinese persons. Twenty-nine patients (35 scars) who had scars for less than 6 months were recruited into the prevention group, and 27 patients (36 scars) who had scars for more than 6 months were recruited into the treatment arm of the study. Each received pulse dye laser treatment (585 nm, 1.5-msec pulse duration, 5-mm spot size, 7-8 J/cm(2)) for three to six treatments at 8-week intervals. Half of the scar was treated with the laser and the other half was used as a control. All patients were assessed for subjective improvement with the use of a structured questionnaire and objectively with ultrasonography for thickness and a cutometer for viscoelasticity. Scars were marked on every patient and mapped with a translucent paper at the first appointment to ensure the consistency of location. At the end of the study, 15 patients from the prevention group (15 scars) and 23 patients from the treatment group (34 scars) agreed to return for spectrophotometer assessment. Fifty-four percent of patients in the prevention group and 66% of patients in the treatment group considered their scars to be better or much better. For both groups of patients, there was significant improvement in term of pruritics after laser treatment. For objective assessment, although scar thickness reduced significantly compared to baseline in the treatment group, such change was not significant when changes in the control side were taken into consideration. There was insignificant change in viscoelasticity. Spectrophometer assessment indicated a significant degree of lightening in the treatment group. Our study indicated that although there was significant symptomatic improvement, there was an insignificant degree of objective improvement in terms of scar thickness and viscoelasticity in the prevention group compared to the control group. Our findings are in line with several previous controlled studies and contradict the results of several others. Such differences can be due to differences in assessment methodology, laser settings, skin type, and scar location. Suprapurpuric pulsed dye laser should not be considered as the standard of practice for the treatment and prevention of hypertrophic surgical scars especially in the chest in Asians patients.

Tyrosine-Induced Melanogenesis Shows Differences in Morphologic and Melanogenic Preferences of Melanosomes from Light and Dark Skin Types

The quality, quantity and distribution of melanosomes in epidermis play a crucial role in the determination of skin color and its sensitivity to UV radiation. Melanocyte cultures originating from individuals with light and dark skin types were grown in media with varying concentration of L-tyrosine. Melanosomal melanin content and the size of the organelles were measured after subcellular fractionation. In light-skin type cells, increased melanin production resulted in a more elliptical shape of melanosomes. In melanosomes that constitutively produce more melanin, the tyrosine-induced melanogenesis caused enlargement in all dimensions. X-ray microanalysis provided evidence that the increase in sulfur content induced by high tyrosine concentration was more prominent in the melanosomes from light skin types. A ratio between pheomelanin and eumelanin found in light-skin type melanosomes by HPLC was increased more markedly than that in melanosomes from dark skin melanocytes. These findings suggest that the melanocytes of light-skinned individuals exhibit a preference for pheomelanogenesis. Pheomelanin production is a thiol-consuming process and that might increase the risk of oxidation stress in these cells. This fact, together with the limited ability of pheomelanin to absorb UV radiation may lead to an elevated skin cancer risk among light-skinned individuals.

The impact of epidermal melanin on objective measurements of human skin colour.

Objective measurements of human skin colour were made with a tristimulus (L*a*b*) chromameter in a range of different ethnic skin types. These were compared with biochemical measurements of melanin content, melanin composition and melanosome size in skin biopsies obtained from the same sites. L*, a* and b* values were found to vary significantly with ethnicity. In general, constitutively dark skin types have lower L* values, higher a* values and higher b* values than constitutively light skin types. Total epidermal melanin content appears to be the primary determinant of L* values in human skin (r = -0.88; P < 0.00001), whilst melanosome size also has a significant but more subtle influence on L* values (r = -0.73; P < 0.00001). There is also a strong positive contribution to a* values from epidermal melanin (r = 0.66, P < 0.00001), which accounts for the ethnic variation in a* values observed in this study. Melanin is also a major contributor to b* values in lighter skin types (r = 0.71, P < 0.00001). However, this relationship breaks down in darker skin types where b* values actually reach a maximum and then decrease as the concentration of melanin in the skin increases. This appears to be because of optical masking of yellow light by high concentrations of melanin in the epidermis. Analysis of the relationships between L*, a* and b* values in human skin indicate that they are very closely interrelated, and suggest that the optical properties of melanin in the epidermis are very similar to those of a dye on a fabric substrate.

Ethnic variation in melanin content and composition in photoexposed and photoprotected human skin.

We have examined the quantity and composition of melanin in both photoprotected (volar upper arm) and chronically photoexposed (dorsal forearm) skin from a range of different ethnic skin types including African, Indian, Mexican, Chinese and European. The most lightly pigmented (European, Chinese and Mexican) skin types have approximately half as much epidermal melanin as the most darkly pigmented (African and Indian) skin types. However, the composition of melanin in these lighter skin types is comparatively more enriched with lightly coloured, alkali-soluble melanin components (up to three-fold). Regardless of ethnicity, epidermal melanin content is significantly greater in chronically photoexposed skin than it is in corresponding photoprotected skin (up to two-fold). However, by comparison there is only a modest enrichment of lightly coloured, alkali soluble melanin components in photoprotected skin (up to 1.3-fold). Analysis of melanosomes extracted from the epidermis in these subjects indicates that the proportion of spheroidal melanosomes is low in all skin types examined (<10%). This suggests that in human skin, pheomelanin is a very minor component of epidermal melanin, even in the lightest (European) skin types. Analysis of melanosome size revealed a significant and progressive variation in size with ethnicity: African skin having the largest melanosomes followed in turn by Indian, Mexican, Chinese and European. On the basis of these findings, we propose that variation in skin pigmentation is strongly influenced by both the amount and the composition (or colour) of the melanin in the epidermis. Variation in melanosome size may also play a significant role. However, the data also suggest that in human skin there are subtle differences in the mechanisms associated with the maintenance of constitutive pigmentation and facultative hyperpigmentation, respectively.

Melanin content of cultured human melanocytes and UV-induced cytotoxicity

Cultured melanocytes originating from persons with different skin phototypes were utilized for measurement of endonuclease sensitive sites induced by UVB and the determination of cell survival after UVA or UVB irradiation. During culture, the melanocytes largely maintained their phenotypic characteristics according to their original skin phototype. Total melanin concentrations were 4.9 times higher in the darker skin phototype (IV–VI) melanocytes when compared to the cells from lighter skin phototypes (I–III). Also phaeomelanin contents were higher (2.5 times) in the skin phototype (IV–VI) melanocytes which implies that the cells from light skin types contain less melanin, but a relatively high proportion of phaeomelanin. After UVB irradiation a stronger induction of endonuclease sensitive sites was found for melanocytes with a lower level of total melanin and a high content of pheomelanin. By measuring the clone forming ability in different melanocyte cultures after UVB irradiation, significant better survival was found in case of the cells with the higher melanin content. Despite the large variations in melanin content, no significant difference in survival after UVA irradiation could be demonstrated in this way. Our results suggest a protective effect of melanin for UVB and indicate the importance of the measurements of melanin content and composition when different parameters of UV-induced damage are studied in melanin producing cells.

Skin cancer in heart transplant recipients: risk factor analysis and relevance of immunosuppressive therapy.

The frequency of skin tumors of all types and specifically of squamous cell carcinoma (SCC) is increased in heart transplantation (HT), but the predisposing risk factors are controversial. We studied 300 patients (age 49+/-15 years, 258 men, mean follow-up 4.6 years, follow-up range 1 month to 12 years) who were receiving standard double (cyclosporin plus azathioprine) or triple (cyclosporin plus azathioprine plus prednisone) therapy. The first-year rejection score was calculated for endomyocardial biopsy samples (International Society for Heart and Lung Transplantation grade 0=0, 1A=1, 1B=2, 2=3, 3A=4, 3B=5, and 4=6) and used as an indirect marker of the level of immunosuppression. Multivariate analysis (Cox regression) included age at HT, sex, skin type, first-year rejection score, presence of warts and solar keratosis, lifetime sunlight exposure, and first-year cumulative dose of steroids. The incidence of skin tumors of all types increased from 15% after 5 years to 35% after 10 years after HT according to life-table analysis. Age at HT of >50 years (P:=0.03, RR=5.3), skin type II (P:=0.05, RR=2.6), rejection score of 19 (P:=0.003, RR=5.7), solar keratosis (P:=0.001, RR=6.9), and lifetime sunlight exposure of >30 000 hours (P:=0.0003, RR=7.6) were risk factors for SCC. Older age at HT, light skin type, solar keratosis, greater sunlight exposure, and high rejection score in the first year were independently associated with an increased risk of SCC. The progressive increase in cancer frequency during follow-up and the association with high rejection scores suggest that both the length and level of immunosuppression may be relevant. Because cumulative immunosuppressive load is cumbersome to calculate, a high rejection score in the first year may provide a useful predictor for patients at risk.

Skin Cancer in Heart Transplant Recipients

Background —The frequency of skin tumors of all types and specifically of squamous cell carcinoma (SCC) is increased in heart transplantation (HT), but the predisposing risk factors are controversial. Methods and Results —We studied 300 patients (age 49±15 years, 258 men, mean follow-up 4.6 years, follow-up range 1 month to 12 years) who were receiving standard double (cyclosporin plus azathioprine) or triple (cyclosporin plus azathioprine plus prednisone) therapy. The first-year rejection score was calculated for endomyocardial biopsy samples (International Society for Heart and Lung Transplantation grade 0=0, 1A=1, 1B=2, 2=3, 3A=4, 3B=5, and 4=6) and used as an indirect marker of the level of immunosuppression. Multivariate analysis (Cox regression) included age at HT, sex, skin type, first-year rejection score, presence of warts and solar keratosis, lifetime sunlight exposure, and first-year cumulative dose of steroids. The incidence of skin tumors of all types increased from 15% after 5 years to 35% after 10 years after HT according to life-table analysis. Age at HT of &gt;50 years ( P =0.03, RR=5.3), skin type II ( P =0.05, RR=2.6), rejection score of 19 ( P =0.003, RR=5.7), solar keratosis ( P =0.001, RR=6.9), and lifetime sunlight exposure of &gt;30 000 hours ( P =0.0003, RR=7.6) were risk factors for SCC. Conclusions —Older age at HT, light skin type, solar keratosis, greater sunlight exposure, and high rejection score in the first year were independently associated with an increased risk of SCC. The progressive increase in cancer frequency during follow-up and the association with high rejection scores suggest that both the length and level of immunosuppression may be relevant. Because cumulative immunosuppressive load is cumbersome to calculate, a high rejection score in the first year may provide a useful predictor for patients at risk.

Melanocortin 1 Receptor Variants in an Irish Population

The identification of an association between variants in the human melanocortin 1 receptor (MC1R) gene and red hair and fair skin, as well as the relation between variants of this gene and coat color in animals, suggests that the MC1R is an integral control point in the normal pigmentation phenotype. In order to further define the contribution of MC1R variants to pigmentation in a normal population, we have looked for alterations in this gene in series of individuals from a general Irish population, in whom there is a preponderance of individuals with fair skin type. Seventy-five per cent contained a variant in the MC1R gene, with 30% containing two variants. The Arg151Cys, Arg160Trp, and Asp294His variants were significantly associated with red hair (p = 0.0015, p < 0.001, and p < 0.005, respectively). Importantly, no individuals harboring two of these three variants did not have red hair, although some red-haired individuals only showed one alteration. The same three variants were also over-represented in individuals with light skin type as assessed using a modified Fitzpatrick scale. Despite these associations many subjects with dark hair/darker skin type harbored MC1R variants, but there was no evidence of any particular association of variants with the darker phenotype. The Asp294His variant was similarly associated with red hair in a Dutch population, but was infrequent in red-headed subjects from Sweden. The Asp294His variant was also significantly associated with nonmelanoma skin cancer in a U.K. population. The results show that the Arg151Cys, Arg160Trp, and Asp294His variants are of key significance in determining the pigmentary phenotype and response to ultraviolet radiation, and suggest that in many cases the red-haired component and in some cases fair skin type are inherited as a Mendelian recessive.

Characterization of melanocyte stimulating hormone receptor variant alleles in twins with red hair.

The association between MSHR coding region variation and hair colour in humans has been examined by genotyping 25 red haired and 62 non-red Caucasians, all of whom were 12 years of age and members of a twin pair study. Twelve amino acid substitutions were seen at 11 different sites, nine of these being newly described MSHR variants. The previously reported Val92Met allele shows no association with hair colour, but the three alleles Arg151Cys, Arg160Trp and Asp294His were associated with red hair and one Val60Leu variant was most frequent in fair/blonde and light brown hair colours. Variant MSHR genotypes are associated with lighter skin types and red hair (P < 0.001). However, comparison of the MSHR genotypes in dizygotic twin pairs discordant for red hair colour indicates that the MSHR gene cannot be solely responsible for the red hair phenotype, since five of 13 pairs tested had both haplotypes identical by state (with three of the five having both identical by descent). Rather, it is likely that additional modifier genes exist, making variance in the MSHR gene necessary but not always sufficient, for red hair production.

DNA Repair Capacity for Ultraviolet Light-Induced Damage Is Reduced in Peripheral Lymphocytes from Patients with Basal Cell Carcinoma

Sunlight exposure and certain host factors such as red hair and fair skin are established risk factors for non-melanoma skin cancers. Because deficient DNA repair capacity has contributed to the development of skin cancers in a rare genetic disease, xeroderma pigmentosum, we explored this deficiency as an etiologic factor in a recent population study. We used a new DNA repair assay, the host-cell reactivation, in a clinic-based case-control study to test the hypothesis that reduced DNA repair is the underlying molecular mechanism for the development of sunlight-induced basal cell carcinoma. The peripheral lymphocytes from 88 patients with primary BCC and 135 cancer-free controls were tested for their capacity to repair ultraviolet light-induced DNA damage in a reporter gene, chloramphenicol acetyl transferase. All subjects were between the ages of 20 and 60 years and were frequency matched by age (+/- 5) and sex. Among those who reported frequent sunbathing, poor tanning ability, a history of multiple sunburns, exposure to chemicals, or multiple medical irradiations, the BCC patients had significantly lower DNA repair capacity than controls (p < 0.05). DNA repair capacity was also found substantially lower in the basal cell carcinoma patients who had red hair and light skin (type I). Compared to controls, basal cell carcinoma cases with selected risk factors had a relative decrease in DNA repair capacity of 10-28%. These findings provided evidence that reduced DNA repair capacity is one of the underlying molecular mechanisms for sunlight-induced skin carcinogenesis in the general population.