Basal cell carcinomas of the scalp after radiotherapy for tinea capitis in childhood: A genetic and epigenetic study with comparison with basal cell carcinomas evolving in chronically sun-exposed areas.

BACKGROUND: Basal cell carcinoma (BCC) has been mostly associated with sun exposure, but ionizing radiation is also a known risk factor. It is not clear if the pathogenesis of BCC, namely at a genomic and epigenetic level, differs according to the underlying triggering factors. OBJECTIVE: The present study aims to compare genetic and epigenetic changes in BCCs related to ionizing radiation and chronic sun exposure. METHODS: Tumor samples from BCCs of the scalp in patients submitted to radiotherapy to treat tinea capitis in childhood and BCCs from sun-exposed areas were analysed through array comparative genomic hybridization (array-CGH) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) to detect copy number alterations and methylation status of specific genes. RESULTS: Genomic characterization of tumor samples revealed several copy number gains and losses in all chromosomes, with the most frequent gains observed at 2p, 6p, 12p, 14q, 15q, 18q, Xp and Yp, and the most frequent losses observed at 3q, 14q, 16p, 17q, 22q, Xp, Yp and Yq. We developed a statistical model, encompassing gains in 3p and 16p and losses in 14q and 20p, with potential to discriminate BCC samples with sporadic aetiology from BCC samples that evolve after radiotherapy in childhood for the treatment of tinea capitis, which presented statistical significance (P = 0.003). Few methylated genes were detected through MS-MLPA, most frequently RARB and CD44. CONCLUSIONS: Our study represents a step forward in the understanding of the genetic mechanisms underlying the pathogenesis of BCC and suggests potential differences according to the underlying ris k factors.

Multiple Basal Cell Carcinomas of the Scalp After Radiotherapy: Genomic Study in a Case With Latency Period Over 80 Years.

ABSTRACT: Basal cell carcinoma (BCC) has been linked mostly to ultraviolet radiation exposure, but ionizing radiation has also been implicated in the genesis of a subset of BCCs occurring after radiotherapy. We present a 93-year-old woman with 4 BCCs of the scalp after radiotherapy for tinea capitis, diagnosed after a latency period of over 80 years. The largest lesion was located on the right temporal region and corresponded to a BCC of mixed type, with nodular, infiltrative, and micronodular components. We performed genomic study with array comparative genomic hybridization in samples from each BCC, which revealed more imbalances in the largest lesion than in the remaining ones, correlating with its higher histological complexity. Furthermore, this was the only lesion presenting loss at 2p22.3, where is mapped the BIRC6 gene associated with regulation of apoptosis, and loss at 16q24.3, where is mapped FANCA gene, responsible for DNA repair and maintenance of chromosome stability. Despite these differences, there were aberrations shared by all tumor samples, suggesting a common genetic signature. Our report describes, to the best of our knowledge, the longest latency period between exposure to radiotherapy and the diagnosis of BCC. The genomic study showed imbalances common to all tumor samples but also differences that could explain their heterogeneity in terms of histological subtype and biological potential. In addition, these differences could also be a consequence of different times in the evolution of the lesions at the moment of presentation, thus having a diverse combination of accumulated genomic imbalances.

Prevalence of cytogenetic abnormalities and FMR1 gene premutation in a Portuguese population with premature ovarian insufficiency.

INTRODUCTION: Chromosome abnormalities contribute to about 10% of cases of premature ovarian insufficiency. Most are associated with X chromosome. Fragile mental retardation 1 (FMR1) gene premutation has an estimated prevalence of 1% - 7% in sporadic cases and up to 13% in familial cases. Our aim was to describe the clinical characteristics, cytogenetic and FMR1 testing of a Portuguese population with premature ovarian insufficiency. MATERIAL AND METHODS: Women diagnosed with premature ovarian insufficiency in a Portuguese tertiary centre were retrospectivelyanalysed. Data were retrieved from electronic medical records including clinical characteristics, cytogenetic and FMR1 testing. The main outcome measures were the prevalence of chromosome abnormalities and FMR1 premutation in a Portuguese population with premature ovarian insufficiency. RESULTS: Ninety-four patients were included, with a median age at menopause of 36 years. The prevalence of chromosome abnormalities was 16.5% (14/85) and most were X chromosome related (78.6%). The prevalence of FMR1 premutation was 6.7% (6/90). The prevalence of karyotypic abnormalities or FMR1 premutation did not differ significantly between familial and sporadic cases. Neither chromosome abnormalities nor FMR1 premutation influenced age at menopause or follicle stimulating hormone levels at diagnosis in premature ovarian insufficiency patients. DISCUSSION: This is the first study describing the clinical characteristics and both cytogenetic and FMR1 testing in a Portuguese population with premature ovarian insufficiency. The rate of chromosome abnormalities in our sample was higher than in other populations, while the prevalence of FMR1 premutation was similar to previous reports. CONCLUSION: Our results underline the importance of genetic screening in premature ovarian insufficiency patients in both etiological study and genetic counselling.

Introdução: As anomalias cromossómicas contribuem para 10% dos casos de insuficiência ovárica prematura estando maioritariamente associadas ao cromossoma X. A pré-mutação do gene fragile mental retardation 1 (FMR1) tem uma prevalência estimada de 1% - 7% nos casos esporádicos e até 13% nos casos familiares. O nosso objetivo foi descrever as características clínicas e a análise citogenética e do gene FMR1 de uma população Portuguesa com insuficiência ovárica prematura. Material e Métodos: Análise retrospetiva das mulheres com o diagnóstico de insuficiência ovárica prematura vigiadas num hospital terciário Português. Recolha de dados através do processo médico eletrónico incluindo características clínicas, análise citogenética e análise do gene FMR1. Os desfechos principais foram a prevalência de anomalias cromossómicas e da pré-mutação FMR1 numa população Portuguesa com insuficiência ovárica prematura. Resultados: Foram incluídas 94 doentes, com uma mediana de idade de menopausa de 36 anos. A prevalência de anomalias cromossómicas foi 16,5% (14/85) e a maioria estavam relacionadas com o cromossoma X (78,6%, n = 11). A prevalência da pré-mutação FMR1 foi de 6,7% (6/90). A prevalência de anomalias cromossómicas ou pré-mutação FMR1 não diferiu entre casos esporádicos e familiares. Nem as anomalias cromossómicas nem a pré-mutação FMR1 influenciaram a idade de menopausa ou os níveis da hormona estimulante dos folículos capilares aquando do diagnóstico na população com insuficiência ovárica prematura. Discussão: Este é o primeiro estudo a descrever as características clínicas e a análise citogenética e do gene FMR1 numa população Portuguesa com insuficiência ovárica prematura. A prevalência de anomalias cromossómicas na nossa amostra foi superior à descrita para outras populações, enquanto a prevalência da pré-mutação FMR1 foi semelhante à descrita em estudos anteriores. Conclusão: Os nossos resultados sublinham a importância do rastreio genético em doentes com insuficiência ovárica prematura, quer no estudo etiológico, quer no aconselhamento genético.

Iodine deficiency and thyroid nodular pathology--epidemiological and cancer characteristics in different populations: Portugal and South Africa.

BACKGROUND: The prevalence and pathology pattern of iodine deficiency (ID) related disorders are influenced by the dietary iodine intake: low iodine leads to thyroid nodular enlargement, to an increase in the incidence of thyroid cancer, an increase in anaplastic carcinomas and to an alteration in the papillary to follicular neoplasia ratio. This study aims at highlighting the effects of ID by comparatively evaluating the pattern of thyroid nodular pathology in different populations that, although geographically distant and heterogeneous, both had iodine deficiency at the time of data gathering and are at high altitude: Beira Interior (BI) in Portugal and Johannesburg (JHB) in South Africa. (S.A.) Mandatory salt iodization introduced in S. A. in 1995 has recently been shown to have resulted in the correction of ID. METHODS: Evaluation of thyroid histology reports over a 6 year period in BI and a 5 year period in the JHB area. RESULTS: Region of BI: 278 patients with histology reports-60 were malignancies (21.2 %): 31 papillary carcinomas, 22 follicular cancers (18 follicular carcinomas and 4 Hürthle cell tumours), 3 medullary carcinomas and 4 anaplastic carcinomas. Region of JHB: 136 histology reports- 33 were malignancies (24.3 %): 13 papillary carcinomas, 15 follicular cancers (10 follicular carcinomas and 5 Hürthle cell tumours), 1 medullary carcinoma, 3 anaplastic carcinomas and 1 metastatic carcinoma into the thyroid. There was an overlap in the frequencies of all histology types, of particular relevance in the relatively high anaplastic carcinoma incidences and in the papillary to follicular carcinoma ratios which was close to 1 in both areas- BI area ratio: 1.4 and JHB area ratio: 0.87, with overlapping 95 % CI's, also confirmed by the results of the chi-square calculations. CONCLUSIONS: During the study periods evaluated both study areas displayed pathology patterns usually found in ID. Public information regarding the negative consequences of ID combined with the availability of affordable iodized salt are likely to achieve the goal of the elimination of ID. Sea based nutrition, (naturally iodine containing), may also contribute to the elimination of ID, particularly at times when salt restriction tends to be generally advised.