Reassessing the clinical spectrum associated with hereditary leiomyomatosis and renal cell carcinoma syndrome in French FH mutation carriers.

We addressed uncertainties regarding hereditary leiomyomatosis and renal cell carcinoma (HLRCC) by exploring all French cases, representing the largest series to date. Fumarate hydratase (FH) germline testing was performed with Sanger sequencing and qPCR/MLPA. Enzyme activity was measured when necessary. We carried out whenever possible a pathology review of RCC and S-(2-succino)-cysteine (2SC)/fumarate hydratase immunohistochemistry. We estimated survival using non-parametric Kaplan-Meier. There were 182 cases from 114 families. Thirty-seven RCC were diagnosed in 34 carriers (19%) at a median age of 40. Among the 23 RCC with pathology review, 13 were papillary type 2. There were 4 papillary RCC of unspecified type, 3 unclassified, 2 tubulocystic, and 1 collecting duct (CD) RCC, all 2SC+ and most (8/10) FH-. Of the remaining 14, papillary type 2, papillary unspecified, CD, and clear cell histologies were reported. The vast majority of RCC (82%) were metastatic at diagnosis or rapidly became metastatic. Median survival for metastatic disease was 18 months (95%CI: 11-29). 133 cases (73%) had a history of cutaneous leiomyomas, 3 developed skin leiomyosarcoma. Uterine leiomyomas were frequent in women (77%), but no sarcomas were observed. Only 2 cases had pheochromocytomas/paraganglioma. CONCLUSION: Our findings have direct implications regarding the identification and management of HLRCC patients.

Germline BAP1 mutations predispose also to multiple basal cell carcinomas.

The BRCA1-associated protein 1 (BAP1) gene encodes a nuclear deubiquitin enzyme which acts as a tumour suppressor. Loss of function germline mutations of BAP1 have been associated with an enhanced risk of uveal and cutaneous melanomas, mesothelioma, clear cell renal cancer and atypical cutaneous melanocytic proliferations. In two independent BAP1 families, we noticed an unusual frequency of basal cell carcinomas (BCCs). Indeed, 19 BCCs were diagnosed in four patients, either of superficial (13/19) or nodular (6/19) subtype; they were all located in chronic sun-exposed areas (limbs, head or neck). Immunohistochemistry (IHC) identified in the 19 tumours, complete or partial loss of BAP1 protein nuclear expression, restricted to the BCC nests. A control study was conducted in 22 sporadic BCCs in 22 subjects under 65 without known associated BAP1 tumours: no loss of BAP1 expression was found. Overall, our observations suggest that BCCs are part of the BAP1 cancer syndrome, perhaps in relation with chronic sun exposure and melanocortin 1 receptor (MC1R) variants. In conclusion, cutaneous follow-up of BAP1 carriers should not only aim to detect melanocytic neoplasms but also BCCs.

[Recommendations for genetic testing and management of individuals genetically at-risk of cutaneous melanoma]. / Recommandations pour le diagnostic de prédisposition génétique au mélanome cutané et pour la prise en charge des personnes à risque.

Cutaneous melanoma is a multifactorial disease resulting from both environmental and genetic factors. Five susceptibility genes have been identified over the past years, comprising high-risk susceptibility genes (CDKN2A, CDK4, and BAP1 genes) and intermediate-risk susceptibility genes (MITF, and MC1R genes). The aim of this expert consensus was to define clinical contexts justifying genetic analyses, to describe the conduct of these analyses, and to propose surveillance recommendations. Given the regulatory constraints, it is recommended that dermatologists work in tandem with a geneticist. Genetic analysis may be prescribed when at least two episodes of histologically proven invasive cutaneous melanoma have been diagnosed before the age of 75 years in two 1st or 2nd degree relatives or in the same individual. The occurrence in the same individual or in a relative of invasive cutaneous melanoma with ocular melanoma, pancreatic cancer, renal cancer, mesothelioma or a central nervous system tumour are also indications for genetic testing. Management is based upon properly managed photoprotection and dermatological monitoring according to genetic status. Finally, depending on the mutated gene and the familial history, associated tumour risks require specific management (e.g. ocular melanoma, pancreatic cancer). Due to the rapid progress in genetics, these recommendations will need to be updated regularly.

Genital and anorectal mucosal melanoma is associated with cutaneous melanoma in patients and in families.

BACKGROUND: Genital and anorectal mucosal melanomas (GAMMs) are rare compared with cutaneous melanoma (CM). Many epidemiological and genetic studies have been carried out on CM. In contrast, the genetic and environmental risk factors for GAMM have been poorly documented up to now. OBJECTIVES: To compare the distribution of pigmentation and naevus phenotypes, sun exposure and family history of melanoma between patients with GAMM and CM. METHODS: We compared two series of patients, 81 with GAMM and 293 with CM. RESULTS: Patients with GAMM and CM did not show significant differences for phenotypic risk factors. However, patients with GAMM tended to display red hair (11% vs. 5·5%, P = 0·08) and a poor tanning ability (22% vs. 13·3%, P = 0·06) at a higher frequency than patients with CM. A family history of melanoma was significantly more frequent with GAMM than with CM (18% vs. 7·5%, P = 0·005). Apart from the GAMM index case, affected relatives had CM except in one family. The frequency of multiple primary melanomas (MPMs) was similar in the GAMM and CM series (6% vs. 5·3%, P = 0·43). All patients with GAMM and MPM had only one GAMM primary, while the other primary was cutaneous. No CDKN2A germline mutation was detected in patients with GAMM. CONCLUSIONS: This study shows that GAMM and CM may occur in the same patient, and GAMM may develop in a familial setting. The association of both GAMM and CM in patients and families suggests shared genetic factors by these two types of melanoma.

Novel FH mutation in a patient with cutaneous leiomyomatosis associated with cutis verticis gyrata, eruptive collagenoma and Charcot-Marie-Tooth disease.

Multiple cutaneous and uterine leiomyomatosis (MCUL)/hereditary leiomyomatosis and renal cell cancer (HLRCC) (OMIM 150800/OMIM 605839) is a rare hereditary disorder leading to the development of benign cutaneous and uterine smooth muscle tumours in young adults.(1,2) This disease is characterized by an increased risk of developing renal cell carcinomas.(3) It results from dominantly inherited autosomal mutations in the fumarate hydratase (FH) gene.(4) This gene encodes a Krebs cycle enzyme, present in both cytosolic and mitochondrial compartments, and probably acts as a tumour suppressor gene. We report a 22-year-old man affected by cutaneous leiomyomatosis associated with cutis verticis gyrata, disseminated collagenoma and Charcot-Marie-Tooth disease, who was harbouring the novel FH gene mutation c.821C > T, p.Ala274Val.

The contribution of large genomic deletions at the CDKN2A locus to the burden of familial melanoma.

Mutations in two genes encoding cell cycle regulatory proteins have been shown to cause familial cutaneous malignant melanoma (CMM). About 20% of melanoma-prone families bear a point mutation in the CDKN2A locus at 9p21, which encodes two unrelated proteins, p16(INK4a) and p14(ARF). Rare mutations in CDK4 have also been linked to the disease. Although the CDKN2A gene has been shown to be the major melanoma predisposing gene, there remains a significant proportion of melanoma kindreds linked to 9p21 in which germline mutations of CDKN2A have not been identified through direct exon sequencing. The purpose of this study was to assess the contribution of large rearrangements in CDKN2A to the disease in melanoma-prone families using multiplex ligation-dependent probe amplification. We examined 214 patients from independent pedigrees with at least two CMM cases. All had been tested for CDKN2A and CDK4 point mutation, and 47 were found positive. Among the remaining 167 negative patients, one carried a novel genomic deletion of CDKN2A exon 2. Overall, genomic deletions represented 2.1% of total mutations in this series (1 of 48), confirming that they explain a very small proportion of CMM susceptibility. In addition, we excluded a new gene on 9p21, KLHL9, as being a major CMM gene.

Impact of the MDM2 SNP309 and p53 Arg72Pro polymorphism on age of tumour onset in Li-Fraumeni syndrome.

Li-Fraumeni syndrome, resulting from p53 (TP53) germline mutations, represents one of the most devastating genetic predispositions to cancer. Recently, the MDM2 SNP309 (T-->G variation) was shown to be associated with accelerated tumour formation in p53 mutation carriers. The impact of the common p53 codon 72 polymorphism on cancer risk remains controversial. We therefore investigated the effect of these two polymorphisms in 61 French carriers of the p53 germline mutation. The mean age of tumour onset in MDMD2 SNP309 G allele carriers (19.6 years) was significantly different from that observed in patients homozygous for the T allele (29.9 years, p<0.05). For the p53 codon 72 polymorphism, the mean age of tumour onset in Arg allele carriers (21.8 years) was also different from that of Pro/Pro patients (34.4 years, p<0.05). We observed a cumulative effect of both polymorphisms because the mean ages of tumour onset in carriers of the MDM2G and p53Arg alleles (16.9 years) and those with the MDM2T/T and p53Pro/Pro genotypes (43 years) were clearly different (p<0.02). Therefore, our results confirm the impact of the MDM2 SNP309 G allele on the age of tumour onset in germline p53 mutation carriers, and suggest that this effect may be amplified by the p53 72Arg allele. Polymorphisms affecting p53 degradation therefore represent one of the rare examples of modifier genetic factors identified to date in mendelian predispositions to cancer.

Comprehensive analysis of CDKN2A (p16INK4A/p14ARF) and CDKN2B genes in 53 melanoma index cases considered to be at heightened risk of melanoma.

OBJECTIVE: Comprehensive analysis of the 9p21 locus including the CDKN2A, ARF, and CDKN2B genes in 53 individuals from melanoma index cases considered to be at heightened risk of melanoma. METHODS AND RESULTS: Using a combination of DNA sequencing, gene copy number by real time quantitative PCR, linkage analysis, and transcript analysis in haploid somatic cell hybrids, we found no evidence for germline alteration in either coding or non-coding domains of CDKN2A and CDKN2B. However, we identified a p14ARF exon 1beta missense germline mutation (G16D) in a melanoma-neural system tumour syndrome (CMM+NST) family and a 8474 bp germline deletion from 196 bp upstream of p14ARF exon 1beta initiation codon to 11233 bp upstream of exon 1alpha of p16(INK4A) in a family with five melanoma cases. For three out of 10 families with at least three melanoma cases, the disease gene was unlinked to the 9p21 region, while linkage analysis was not fully conclusive for seven families. CONCLUSIONS: These data reinforce the hypothesis that ARF is a melanoma susceptibility gene and suggest that germline deletions specifically affecting p14ARF may not be solely responsible for NST susceptibility. Predisposition to CMM+NST could either be due to complete disruption of the CDKN2A locus or be the result of more complex genetic inheritance. In addition, the absence of any genetic alteration in 50 melanoma prone families or patients suggests the presence of additional tumour suppressor genes possibly in the 9p21 region, and on other chromosomes.

[CDKN2A gene mutation and loss of p16 protein activity in a patient on levodopa presenting sporadic multiple primary melanoma]. / Mutation du gène CDKN2A et perte d'activité de la protéine p16 chez un malade traité par L-Dopa et atteint de mélanomes sporadiques multiples.

BACKGROUND: Cutaneous melanoma is a complex disease involving genetic and environmental factors. Levodopa has been incriminated in the development and/or progression of melanoma. OBSERVATION: We report the case of a man treated with levodopa and a dopadecarboxylase inhibitor for Parkinson's disease and presenting 22 cutaneous melanomas over a 4-year period. The patient is of phototype II and presents multiple nevi. Genetic analysis of predisposing genes demonstrated a CDKN2A mutation with loss of p16 activity. DISCUSSION: Multiple melanomas may be associated with genetic predisposition, and screening for the latter should be performed. The exceptionally high number of melanomas developed by our patient raised suspicions about levodopa, a precursor in melanin synthesis, as a potential inducer. Increased dermatologic controls and screening for predisposing genetic factors appear to us to be warranted in the event of melanoma development in patients on levodopa.

Mutations at BRCA1: the medullary breast carcinoma revisited.

BRCA1-associated breast cancers (BRCA1-BCs) frequently harbor a high histoprognostic grade, p53 alterations, and estrogen receptor negativity. Although these parameters predict a poor outlook, the overall survival in BRCA1-BCs is equivalent to or even better than that in sporadic cases. These features are reminiscent of what is observed for breast carcinoma of the medullary type, a high-grade tumor with a particular favorable course. To explore a possible relationship between this phenotype and BRCA1 mutations, we first compared 32 BRCA1-BCs and 200 consecutive cases of breast cancer without familial history for the prevalence of typical medullary breast carcinoma (TMC) using the criteria given by Ridolfi et al. [R. Ridolfi et al, Cancer (Phila.), 40: 1365-1385, 1977]. Second, we searched for BRCA1 mutations in a set of 18 cases of TMC, using denaturing gradient gel electrophoresis and Cleavase fragment length polymorphism scanning. Six of 32 (19%) BRCA1-BCs were of the TMC type, compared to 0 of 200 controls (P < 0.0001). Among the 18 TMCs, 2 BRCA1 nonsense mutations were found. This corresponds to almost 7 times the contribution of BRCA1 mutations in the general population. Two additional missense mutations were identified. Together, these results suggest that, although TMC and BRCA1-BCs are not strictly coincidental, an important connection between the two populations does exist.

Truncation at conserved terminal regions of BRCA1 protein is associated with highly proliferating hereditary breast cancers.

The existence of two subgroups of BRCA1-associated breast cancer (BC) families has been recently posited: the first with highly proliferating tumors, and the second composed of cases with a low proliferation rate. Our aim was to test whether the proliferation rate of BRCA1-associated breast cancers was affected by the site of the germ line mutation in the BRCA1 gene. We analyzed the distribution of the mitotic index, a histoprognostic grade component shown to segregate in families, matching for germ line mutation location in a series of 28 breast cancers from 20 kindreds. We observed a prevalence of highly proliferating tumors when the mutation occurs in the two terminal conserved domains of the BRCA1 protein, ie., in the amino and carboxyl termini (P = 0.0024). Our data provide evidence for a genotype-phenotype correlation and along with their strong conservation during evolution argue for the importance of these two regions in the control of mammary cell growth.

Overexpression of MDM2, due to enhanced translation, results in inactivation of wild-type p53 in Burkitt's lymphoma cells.

Numerous studies have indicated that inactivation of p53 is one of the essential requirements for the unrestrained growth of tumoral cells. When the status of the p53 gene was examined in various types of lymphoid malignancies, mutations in p53 have been predominantly detected in Burkitt's lymphoma (BL) cells, therefore suggesting that alteration of p53 could specifically contribute to the malignant phenotype of these tumoral cells. In addition to mutations, functional inactivation of p53 can also occur through interaction of the wild-type gene product with various viral or cellular proteins. The cellular MDM2 protein, for example, is able to inhibit p53 tumor suppressor function by concealing its transactivation domain. Mdm2 gene amplification has been described in several types of sarcomas, resulting in overexpression of the MDM2 protein. In this study, we have examined the status of MDM2 and p53 in 20 BL cell lines. Four were found to contain wild-type p53 and to overexpress MDM2 protein. Within these BL cells, both molecules are physically associated since they can be co-precipitated and p53 is inactivated as cells neither arrest in G1 nor enter apoptosis following gamma-radiation. We also report that the high level of the MDM2 protein in BL cells is neither associated with an amplification of the mdm2 gene nor with an elevated level of RNA or an increased protein stability, but is rather due to an enhanced translation ability of the mdm2 RNA. These results indicate that in certain BL cells, overexpression of MDM2 protein regulated at the posttranscriptional level, induces an escape from p53-controlled cell growth.

Genomic stability and wild-type p53 function of lymphoblastoid cells with germ-line p53 mutation.

Increased cancer risk associated with germ-line p53 mutation was linked to a deficit in the ability to maintain genomic stability. Accordingly, normal fibroblasts from cancer-prone individuals accumulate genomic aberrations with concomitant loss of wild-type p53 allele during in vitro culture. We tested whether such changes also occur in EBV-immortalized lymphoblastoid cells. Both normal and p53 germ-line mutant lymphoblastoid cells maintained functional p53 and genomic stability during long term in vitro culture. These unexpected differences between fibroblastic and lymphoblastic cells suggest that phenotypic expression of p53 deficiency is cell type specific. This could contribute to selective tissular localization of tumours observed in patients with Li-Fraumeni syndrome despite the presence of a mutant p53 allele in all cells.

Non-Hodgkin's lymphomas and myeloid disorders: deletions associated with t(2;5) and t(3;5) detected by FISH.

The nucleophosmin (NPM) gene is involved in two recurrent translocations in hematological malignancies: t(2;5) (p23;q35) in anaplastic large cell lymphoma (ALCL) and t(3;5)(q25.1;q34-35) in myelodysplasia and acute non-lymphocytic leukemia (ANLL). Using eight YACs encompassing the 5q34-q35 region, we could easily detect these two translocations. In both types of translocation, probable unexpected deletions were also discovered downstream of the breakpoint at 5q35.

The R71G BRCA1 is a founder Spanish mutation and leads to aberrant splicing of the transcript.

In a BRCA1 screening in familial breast cancer carried out in different centres in Spain, France, and United Kingdom, a missense mutation 330A>G which results in a Arg to Gly change at codon 71 (R71G) was independently identified in 6 families, all of them with Spanish ancestors. This residue coincides with the -2 position of the exon 5 donor splice site. We further investigated the effect of this base substitution on the splicing of BRCA1 mRNA. The sequence analysis of the cDNA indicated that 22 bp of exon 5 were deleted, creating with the first bases of exon 6 a termination codon at position 64, which results in a truncated protein. The BRCA1 haplotype of the R71G carrier patients and Spanish controls was analysed by use of six microsatellites located within or near BRCA1. Our results are consistent with the possibility that these families shared a common ancestry with BRCA1 R71G being a founder mutation of Spanish origin.

Activating point mutations in cyclin-dependent kinase 4 are not seen in sporadic pituitary adenomas, insulinomas or Leydig cell tumours.

Cell cycle dysregulation is one of the defining features of cancer. Cyclin-dependent kinase 4 (CDK4), together with its regulatory subunit cyclin D, governs cell cycle progression through the G1 phase. Cyclin-dependent kinase inhibitors, including p16(INK4A) (encoded by CDKN2A), in turn regulate CDK4. In particular, dysregulation of the p16/CDK4/cyclin D complex has been established in a variety of types of human tumours. Dominant activating mutations affecting codon 24 of the CDK4 gene (replacement of Arg24 by Cys or His) render CDK4 insensitive to p16(INK4) inhibition and are responsible for melanoma susceptibility in some kindreds. However, 'knock-in' mice homozygous for the CDK4(R24C) mutation were noted to develop multiple neoplasia, most commonly including endocrine tumours: pituitary adenomas, insulinomas and Leydig cell testicular tumours. We therefore speculated that sporadic human endocrine tumours might also harbour such mutations. The aim of the current study was to analyze the CDK4 gene for the two characterized activating mutations, R24C and R24H, in sporadic human pituitary adenomas, insulinomas and Leydig cell tumours. We used DNA extracted from 61 pituitary adenomas, and paired tumorous and neighboring normal genomic DNA extracted from 14 insulinoma and 6 Leydig cell tumour samples. Genomic DNA from patients with familial melanoma harbouring the R24C or the R24H mutations served as positive controls. All samples were subjected to PCR, mutation-specific restriction digests and/or sequencing. Both methodologies failed to detect mutations at these two sites in any of the sporadic endocrine tumours including pituitary adenomas, benign or malignant insulinomas or Leydig cell tumours, while the positive controls showed the expected heterozygote patterns. Protein expression of CDK4 was demonstrated by immunohistochemistry and Western blotting in pituitary and pancreatic samples. These data suggest that the changes in the regulatory 'hot-spot' on the CDK4 gene, causing various endocrine tumours in CDK4(R24C/R24C )mice, are not a major factor in sporadic pituitary, insulin beta-cell or Leydig cell tumorigenesis.

Patterns of familial aggregation of three melanoma risk factors: great number of naevi, light phototype and high degree of sun exposure.

BACKGROUND: Besides melanoma susceptibility genes and shared environmental exposures, part of the familial clustering of cutaneous malignant melanoma (CMM) might be due to familial aggregation of melanoma-associated phenotypes. Our goal was to assess the patterns of familial aggregation of three melanoma risk factors: great number of naevi (GNN), light phototype (LP) and high degree of sun exposure (HDSE). METHODS: Familial aggregation of GNN, LP and HDSE was investigated in 66 French families with at least two CMM cases and was measured by the asssociation of the relatives' traits with the probands' traits, using the generalized estimating equations approach. The probands were the melanoma cases leading to ascertainment of the families, subdivided into cases (with the trait studied) and controls (without the trait). RESULTS: We found significant evidence for familial aggregation of GNN only among sibs (OR = 3.7, 95% CI : 1.4-10.5, P = 0.01), of LP among blood relatives (OR = 3.8, 95% CI : 1.8-8.0, P = 0.004) and of HDSE among blood relatives (OR = 4.5, 95% CI : 2.1-9.9, P < 0.001) and spouses (OR = 44.3, 95% CI : 5.1-382.2, P < 10(-3)). These results suggest that genetic factors might account for the clustering of GNN and LP and shared environment for the aggregation of HDSE. The GNN clustering was lower in families with increasing numbers of CMM (>/=3 cases) or presence of p16 mutations, the opposite being observed for LP and HDSE. Moreover, the familial aggregation of LP was significantly lower in families with highly sun-exposed members. CONCLUSION: Melanoma might not only result from specific genetic and environmental factors but also from those underlying melanoma-associated traits involving complex gene-gene and gene-environment interactions.

Association between germ cell tumours, large numbers of naevi, atypical naevi and melanoma.

Identifying groups of subjects at high risk for the development of melanoma is crucial for the early diagnosis of curable tumours. In the present study, we performed a skin examination in a group of 63 patients followed up after treatment of germ cell tumours (GCTs) who were referred to the dermatologist for multiple pigmented cutaneous spots. Forty-nine patients bearing a great number of naevi or atypical naevi were included in the study. Two thin cutaneous melanomas were discovered in two patients. In addition, a third patient had had a conjunctival melanoma since treatment of the GCT. Our study confirms the presence of atypical naevi in a subgroup of GCT patients, who are shown to be at high risk of developing melanoma. Patients harbouring multiple pigmented spots should be referred for a skin examination aimed at early detection of curable melanomas, and should be advised to protect themselves from sun exposure.