Longitudinal Study of Different Progression Patterns in High-Risk Cutaneous Squamous Cell Carcinoma. / Estudio longitudinal de los diferentes patrones de progresión en el carcinoma cutáneo de células escamosas de alto riesgo.

BACKGROUND AND OBJECTIVE: Cutaneous squamous cell carcinoma (cSCC) is the second leading cause of skin cancer mortality in Europe. Few studies have analyzed the different pathways of this tumor progression in its natural history. The main objective of this study was to analyze the different metastatic and progression pathways and their temporal occurrence in the evolution of cSCC. MATERIAL AND METHOD: We conducted a multicenter, retrospective, and observational study of consecutive high-risk sSCCs included in the SQUAMATA project. RESULTS: A total of 222 out of the 1346 patients included relapsed. The most frequent route of progression was the lymphatic one (62.6%). A total of 20.2% of the cases with lymphatic progression developed distant metastases. Only 1 case (3.1%) of distant metastasis followed local recurrence without previous lymphatic metastasis. The median time to disease-related mortality was longer in patients who developed systemic metastases than in those who died of locoregional progression. CONCLUSIONS: The mortality of patients with cSCC is mostly due to the regional progression of their lymphatic metastases. The appearance of distant metastases is practically always (96.9%) associated with previous lymphatic metastatic progression. Therefore, in the future, new studies will be needed to assess the regional management of cSCC in both surgical and adjuvant therapies.

Requirements for Accessing New Dermatology Drugs in Spain: Results of the EQUIDAD Study. / Condicionantes de acceso a nuevos medicamentos dermatológicos en España: resultados del proyecto EQUIDAD.

BACKGROUND: Although the Spanish Ministry of Health prepares national therapeutic positioning reports (TPRs) and drug reimbursement policies, each of the country's 17 autonomous communities (ACs) is responsible for health care services and prescription requirements in its territory. The aim of the EQUIDAD study was to describe and explore potential differences in prescription requirements for new dermatology drugs across the autonomous communities. MATERIAL AND METHODS: Cross-sectional study conducted in April and May, 2023. Two dermatologists with management responsibilities from each autonomous community reported on territorial and more local prescription requirements for drugs covered by national TPRs issued between 2016 and 2022. RESULTS: Thirty-three researchers from 17 autonomous communities participated. The data submitted revealed between-community inequities in access to new drugs. Overall, 64.7% of the regions imposed additional prescription requirements to those mentioned in the TPRs for psoriasis. This percentage was lower for atopic dermatitis (35.3%) and melanoma (11.8%). The most common requirement for accessing a new drug was a previous prescription for another drug. Differences and additional requirements were also detected at the local level (i.e., differences between hospitals within the same autonomous community). CONCLUSIONS: Spain's autonomous communities have multiple regional and local prescription requirements that are not aligned with national TPR recommendations. These differences result in inequitable access to new drugs for both patients and practitioners across Spain.

[Translated article] Requirements for Accessing New Dermatology Drugs in Spain: Results of the EQUIDAD Study.

BACKGROUND: Although the Spanish Ministry of Health prepares national therapeutic positioning reports (TPRs) and drug reimbursement policies, each of the country's 17 autonomous communities (ACs) is responsible for health care services and prescription requirements in its territory. The aim of the EQUIDAD study was to describe and explore potential differences in prescription requirements for new dermatology drugs across the autonomous communities. MATERIAL AND METHODS: Cross-sectional study conducted in April and May, 2023. Two dermatologists with management responsibilities from each autonomous community reported on territorial and more local prescription requirements for drugs covered by national TPRs issued between 2016 and 2022. RESULTS: Thirty-three researchers from 17 autonomous communities participated. The data submitted revealed between-community inequities in access to new drugs. Overall, 64.7% of the regions imposed additional prescription requirements to those mentioned in the TPRs for psoriasis. This percentage was lower for atopic dermatitis (35.3%) and melanoma (11.8%). The most common requirement for accessing a new drug was a previous prescription for another drug. Differences and additional requirements were also detected at the local level (i.e., differences between hospitals within the same autonomous community). CONCLUSIONS: Spain's autonomous communities have multiple regional and local prescription requirements that are not aligned with national TPR recommendations. These differences result in inequitable access to new drugs for both patients and practitioners across Spain.

Tumor Doubling Time in Skin Cancer: Can It Be Estimated and Is it Useful? / ¿Es la estimación del tiempo de duplicación tumoral posible y útil en el cáncer de piel?

Skin cancer, like other cancers, is characterized by the uncontrolled growth of transformed cells. Tumor growth has been studied for decades. We review different methods for measuring skin tumor growth and propose a new system for estimating tumor doubling time that could be useful in the management of skin cancer.

Selection of Quality Indicators for the Certification of Dermato-Oncology Units: The CUDERMA Project Delphi Consensus Study. / Proyecto CUDERMA: Consenso Delphi de los indicadores de calidad para la certificación de las unidades de dermatología de atención en dermato-oncología.

Quality indicators are crucial for standardizing and guaranteeing the quality of health care practices. The Spanish Academy of Dermatology and Venereology (AEDV) launched the CUDERMA Project to define quality indicators for the certification of specialized units in dermatology; the first 2areas selected were psoriasis and dermato-oncology. The aim of this study was to achieve consensus on what should be evaluated by these indicators using a structured process comprising a literature review and selection of an initial list of indicators to be evaluated in a Delphi consensus study following review by a multidisciplinary group of experts. The selected indicators were evaluated by a panel of 28 dermatologists and classified as either «essential¼ or «of excellence¼. The panel agreed on 84 indicators, which will be standardized and used to develop the certification standard for dermato-oncology units.

Outcome of cutaneous squamous cell carcinoma with microscopic residual disease after surgery and usefulness of postoperative radiotherapy: a retrospective cohort study.

BACKGROUND: Microscopic residual disease (MRD) after surgery can be a challenging situation in cutaneous squamous cell carcinoma (CSCC) and there is a lack of evidence concerning its management. OBJECTIVE: To evaluate the prognosis of CSCC with MRD and the usefulness of postoperative radiotherapy (PORT) in CSCC with MRD. METHODS: Retrospective cohort study of CSCC with MRD through a 10-year period (2010-2019) (n = 244). Disease-free survival and event-free survival were assessed using R (v.3.4.1), considering competing risks. Evaluated outcomes were local recurrence (LR), nodal metastases (NMs), and disease-specific death (DSD). RESULTS: Median age was 88y (IQR: 10.5). A total of 145 (59.43%) were men and 69 (28.28%) were immunosuppressed. Median tumour diameter and thickness were 19 and 6.4 mm (IQR 11 and 5.5 mm). Patients treated by re-excision had a relapse rate of 4.3% compared with 11.30% and 29.71% in those who received PORT and observation (P = 0.045). The use of PORT was associated with a lower risk of LR compared with observation (HR = 0.206 [0.049-0.859], P = 0.030), but not with a lower risk of NMs or DSDs. In the multivariable models, PORT was again associated with a lower risk of LR than observation (HR = 0.167 [0.039-0.708], P = 0.014), but not with lower risk of metastasis and death. CONCLUSIONS: We always should try to obtain clear margins after surgery. PORT improves local control in CSCC with MRD, but when administered to the tumour bed, it does not reduce the risk of NM and DSD.

Postoperative radiotherapy provides better local control and long-term outcome in selective cases of cutaneous squamous cell carcinoma with perineural invasion.

BACKGROUND: Perineural invasion (PNI) is a feature of poor prognosis in cutaneous squamous cell carcinoma (CSCC). The benefit of postoperative radiotherapy (PORT) in the management of CSCC with PNI is still not well established. OBJECTIVES: We aimed to evaluate the usefulness of PORT in the treatment of CSCC with PNI so as to determine which patients would best benefit from this type of treatment. METHODS: A retrospective multicenter cohort of 110 CSCCs with PNI was evaluated. Eighteen recurrent cases were excluded for subsequent analysis. We searched for the types of PNI associated with poor outcome and analysed the effectiveness of PORT on different groups of CSCC with PNI. We also assessed for the usefulness of PORT depending on the surgical margin status (either clear or positive). RESULTS: Postoperative radiotherapy showed clear benefit over observation in CSCC with PNI and positive margins after surgery, where the management by observation increased the risk of poor outcome events 2.43 times (P = 0.025), and especially in those with positive margins and PNI ≥0.1 mm, where the risk of poor prognosis is eight times greater following a management by observation (P = 0.0065). Multivariate competing risk analysis preserved statistical significance. CONCLUSIONS: The use of PORT on patients with CSCC with PNI and positive margins after surgery, especially in PNI ≥0.1 mm, significantly improves long-term outcome. The benefit of PORT in cases with clear margins is not as evident, especially in those with PNI of small-calibre nerves. Clinical trials are imperative.

Prognostic factors in patients with primary cutaneous anaplastic large cell lymphoma: a multicentric, retrospective analysis of the Spanish Group of Cutaneous Lymphoma.

BACKGROUND: Reliable prognostic factors for patients with primary cutaneous anaplastic large cell lymphoma (PCALCL) are lacking. OBJECTIVE: To identify prognostic factors for specific survival in patients with PCALCL. METHODS: Using the convenience sampling method, patients with PCALCL diagnosed from May 1986 to August 2017 in 16 University Departments were retrospectively reviewed. RESULTS: One hundred eight patients were included (57 males). Median age at diagnosis was 58 years. All of them showed T1-3N0M0 stages. Seventy per cent of the cases presented with a solitary lesion, mostly at the limbs. Complete response rate after first-line treatment was 87%, and no advantage was observed for any of them (surgery, radiotherapy, chemotherapy or other approaches). Nodal and visceral progression rate was 11% and 2%, respectively. 5-year specific survival (SSV) reached 93%; 97% for T1 patients and 84% for T2/T3 patients (P = 0.031). Five-year SSV for patients developing early cutaneous relapse was 64%; for those with late or no relapse, 96% (P = 0.001). Estimated median SSV for patients showing nodal progression was 103 months (95% CI: 51-155 months); for patients without nodal progression, estimated SSV did not reach the median (P < 0.001). Nodal progression was an independent predictive parameter for shorter survival (P = 0.011). CONCLUSION: Multiple cutaneous lesions at presentation, early skin relapse and nodal progression portrait worse prognosis in patients with PCALCL.

Evidence of the high prevalence of neurological disorders in nonsyndromic X-linked recessive ichthyosis: a retrospective case series.

BACKGROUND: X-linked recessive ichthyosis (XLI) is a relatively common type of ichthyosis caused by a deficiency in the steroid sulfatase (STS) enzyme. It is the only type of ichthyosis that can be both syndromic and nonsyndromic. Typical clinical features include dark-brown scale of variable size favouring the extensor surfaces of the extremities. OBJECTIVES: To characterize clinically nonsyndromic XLI, with a particular focus on extracutaneous manifestations. METHODS: This was a multicentre retrospective review of clinical findings from a case series of patients with a clinical and genetic diagnosis of XLI. RESULTS: We identified 30 patients with XLI belonging to 25 different families carrying a deletion in the STS locus. All patients had dark scales of variable size on the extensor surfaces of the extremities. Lack of flexural involvement and pruritus were common but inconsistent findings, whereas palmoplantar hyperlinearity was absent in all but one patient. A history of orchiopexy was present in 10% and thus was more common than expected vs. the general population (3%). Neurological disorders including epilepsy (13%) and attention deficit hyperactivity disorder (ADHD; 30%) were over-represented in patients with XLI. CONCLUSIONS: This was a retrospective study with a limited number of patients. In the absence of confirmatory genetic testing and family history of the disease, dark-brown scale of the extensor surfaces and the absence of palmoplantar hyperlinearity appear to be the most reliable clinical findings supporting a diagnosis of XLI. Dermatologists should be aware of the high prevalence of ADHD and epilepsy in patients with nonsyndromic XLI.

Novel clinical and molecular findings in Spanish patients with naevoid basal cell carcinoma syndrome.

BACKGROUND: Naevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by developmental alterations and multiple basal cell carcinomas. Mutations in PTCH1, which encodes a membrane receptor for Sonic Hedgehog, are associated with the development of the disease. Most of them produce a truncated protein, which is unable to suppress Smoothened protein and continuously activates the downstream pathway. OBJECTIVES: We aimed to characterize 22 unrelated Spanish patients with NBCCS, the largest cohort with Gorlin syndrome reported to date in Spain. METHODS: Genomic analysis of PTCH1 was performed in patients with NBCCS and controls, and mutations were analysed using bioinformatics tools. RESULTS: We report for the first time two young patients, one each with uterus didelphys and ganglioneuroma, within the context of NBCCS. One patient showing a severe phenotype of the disease had developed basal cell carcinomas since childhood. Sanger sequencing of PTCH1 in this cohort identified 17 novel truncating mutations (11 frameshift, five nonsense and one mutation affecting an exon-intron splice site) and two novel missense mutations that were predicted to be pathogenic. The patients showed great clinical variability and inconsistent genotype-phenotype correlation, as seen in relatives carrying similar mutations. CONCLUSIONS: This study contributes to increase the pool of clinical manifestations of NBCCS, as well as increasing the number of pathogenic mutations identified in PTCH1 predisposing to the condition. The inconsistencies found between phenotype and genotype suggest the involvement of other modifying factors, genetic, epigenetic or environmental.

Rapid growth rate is associated with poor prognosis in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) represents the most common form of skin cancer after basal cell carcinoma, and can be both locally invasive and metastatic to distant sites. Growth rate (GR) has been poorly evaluated in cSCC, despite clinical evidence suggesting that GR is an important risk factor in cSCC. AIM: To analyse the influence of GR in cSCC prognosis. METHODS: We retrospectively evaluated GR in a series of 90 cSCCs and tried to correlate GR with prognosis in cSCC. RESULTS: We demonstrated that tumours with a GR of > 4 mm/month exhibit a higher risk of nodal progression and a shorter progression time to lymph node metastasis in cSCC than those with GR of < 4 mm/month. As expected, GR correlated with tumour proliferation, as determined by Ki-67 expression. CONCLUSIONS: We consider a GR of 4 mm/month as the cutoff point that distinguishes between rapid- and slow-progressing tumours and, more importantly, to identify a subset of high-risk cSCCs.

First-line treatment in lymphomatoid papulosis: a retrospective multicentre study.

BACKGROUND: Data regarding response to treatment in lymphomatoid papulosis (LyP) are scarce. AIM: To assess the daily clinical practice approach to LyP and the response to first-line treatments. METHODS: This was a retrospective study enrolling 252 patients with LyP. RESULTS: Topical steroids, methotrexate and phototherapy were the most common first-line treatments, prescribed for 35%, 20% and 14% of the patients, respectively. Complete response (CR) was achieved in 48% of treated patients. Eczematous lesions significantly increased relative risk (RR) of not achieving CR (RR = 1.76; 95% CI 1.16-2.11). Overall median time to CR was 10 months (95% CI 6-13 months), and 78% of complete responders showed cutaneous relapse; both results were similar for all treatment groups (P > 0.05). Overall estimated median disease-free survival (DFS) was 11 months (95% CI 9-13 months) but DFS for patients treated with phototherapy was 23 months (95% CI 10-36 months; P < 0.03). Having the Type A LyP variant (RR = 2.04; 95% CI 0.96-4.30) and receiving a first-line treatment other than phototherapy (RR = 5.33; 95% CI 0.84-33.89) were significantly associated with cutaneous early relapse. Of the 252 patients, 31 (13%) had associated mycosis fungoides unrelated to therapeutic approach, type of LyP or T-cell receptor clonality. CONCLUSIONS: Current epidemiological, clinical and pathological data support previous results. Topical steroids, phototherapy and methotrexate are the most frequently prescribed first-line treatments. Although CR and cutaneous relapse rates do not differ between them, phototherapy achieves a longer DFS. Presence of Type A LyP and use of topical steroid or methotrexate were associated with an increased risk of early relapse.

Epidermal growth factor receptor expression is associated with poor outcome in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans after basal cell carcinoma, and its incidence is dramatically rising. CSCC is rarely problematic, but given its high frequency, the absolute number of complicated cases is also high. It is necessary to identify molecular markers in order to recognize those CSCCs with poor prognosis. There is controversy concerning the role of epidermal growth factor receptor (EGFR) as a marker of prognosis in CSCC. In addition, EGFR-targeted therapies have emerged in recent years and a better understanding of the role of EGFR in CSCC may be of help for some patients in predicting prognosis and guiding curative management. OBJECTIVES: To evaluate the role of EGFR as a prognostic factor in CSCC. METHODS: We evaluated clinical and histopathological features, including events of poor clinical evolution, in a series of 94 cases of CSCC. We also analysed EGFR expression by immunohistochemistry, fluorescent in situ hybridization and quantitative polymerase chain reaction. RESULTS: We detected EGFR in 85 cases (90%), with overexpression in 33 cases (35%), and aberrant EGFR expression in the cytoplasm in 50 cases (53%). EGFR overexpression in the primary tumours was associated with lymph node progression, tumour-nodes-metastasis stage progression and proliferation (Ki-67 staining) in CSCC. EGFR overexpression and poor grade of differentiation were the strongest independent variables defining lymph node metastasis and progression in CSCC in a logistic regression model. CONCLUSIONS: We demonstrate that EGFR overexpression has prognostic implications associated with lymph node metastasis and progression in CSCC.

MicroRNA (miR)-203 and miR-205 expression patterns identify subgroups of prognosis in cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is the second most widespread cancer in humans and its incidence is rising. These tumours can evolve as diseases of poor prognosis, and therefore it is important to identify new markers to better predict its clinical evolution. OBJECTIVES: We aimed to identify the expression pattern of microRNAs (miRNAs or miRs) at different stages of skin cancer progression in a panel of murine skin cancer cell lines. Owing to the increasing importance of miRNAs in the pathogenesis of cancer, we considered the possibility that miRNAs could help to define the prognosis of CSCC and aimed to evaluate the potential use of miR-203 and miR-205 as biomarkers of prognosis in human tumours. METHODS: Seventy-nine human primary CSCCs were collected at the University Hospital of Salamanca in Spain. We identified differential miRNA expression patterns at different stages of CSCC progression in a well-established panel of murine skin cancer cell lines, and then selected miR-205 and miR-203 to evaluate their association with the clinical prognosis and evolution of human CSCC. RESULTS: miR-205 was expressed in tumours with pathological features recognized as indicators of poor prognosis such as desmoplasia, perineural invasion and infiltrative growth pattern. miR-205 was mainly expressed in undifferentiated areas and in the invasion front, and was associated with both local recurrence and the development of general clinical events of poor evolution. miR-205 expression was an independent variable selected to predict events of poor clinical evolution using the multinomial logistic regression model described in this study. In contrast, miR-203 was mainly expressed in tumours exhibiting the characteristics associated with a good prognosis, was mainly present in well-differentiated zones, and rarely expressed in the invasion front. Therefore, the expression and associations of miR-205 and miR-203 were mostly mutually exclusive. Finally, using a logistic biplot we identified three clusters of patients with differential prognosis based on miR-203 and miR-205 expression, and pathological tumour features. CONCLUSIONS: miR-205 and miR-203 tended to exhibit mutually exclusive expression patterns in human CSCC. This work highlights the utility of miR-205 and miR-203 as prognostic markers in CSCC.

Novel Additions to the AJCC's New Staging Systems for Skin Cancer. / Los nuevos sistemas de estadificación del AJCC incorporan novedades en el cáncer cutáneo.

The eighth edition of the staging manual of the American Joint Committee on Cancer incorporates important changes in the classification of skin cancers. Coming 40 years after the first edition, the latest manual preserves its specific system for Merkel cell carcinoma and takes into account recent publications on the prognosis of squamous cell carcinoma by defining a completely new T category for this neoplasm. Staging for squamous cell carcinoma considers head and neck tumors (excluding the eyelid) and does not offer solutions for other sites except the vulva, penis, and perianal region. Regarding melanoma, use of the mitotic index has been eliminated and the prognosis of the primary tumor is based on Breslow thickness and ulceration. In addition, thickness is now recorded to an accuracy of 0.1mm, and the T0 concept has been introduced to define those metastatic melanomas in which the primary tumor has regressed completely. In this new edition, changes have also been made to the N category of all the skin cancer staging systems, and M1d has been added to the M category for melanoma to refer to metastatic involvement of the central nervous system, which, up to now, had been included in the M1c category. This new system will need to be validated with patient series to determine if it adequately satisfies the objective of tumor risk stratification.

Dermatologic emergencies in a tertiary hospital: A descriptive study. / Estudio descriptivo de urgencias dermatológicas en un hospital terciario.

BACKGROUND AND OBJECTIVE: Dermatology in-house call is uncommon in the Spanish national health system. The objective of the present study was to define the groups of dermatologic diseases and conditions most frequently seen in the emergency department and to evaluate the need for dermatology in-house call in the training of medical residents. MATERIAL AND METHODS: We performed a descriptive study of all patients who attended the emergency department with a skin complaint during a 1-year period (June 2013 to May 2014) and were assessed by 9 dermatology residents. The study variables were date/day, sex, age, diagnosis, special surgical procedures, additional laboratory tests, and need for hospitalization and/or follow-up. We also evaluated patients attending their first scheduled visit to the dermatologist between January and June 2014 in order to compare the most frequent conditions in both groups. RESULTS: A total of 3084 patients attended the emergency room with a skin complaint (5.6% of all visits to the emergency department), and 152 different diagnoses were made. The most frequent groups of diseases were infectious diseases (23%) and eczema (15.1%). The specific conditions seen were acute urticaria (7.6%), contact dermatitis (6.1%), and drug-induced reactions (4.6%). By contrast, the most frequent conditions seen in the 1288 patients who attended a scheduled dermatology appointment were seborrheic keratosis (11.9%), melanocytic nevus (11.5%), and actinic keratosis (8%). A follow-up visit was required in 42% of patients seen in the emergency department. Fourth-year residents generated the lowest number of follow-up visits. CONCLUSIONS: We found that infectious diseases and eczema accounted for almost 40% of all emergency dermatology visits. Our results seem to indicate that the system of in-house call for dermatology residents is very useful for the hospital system and an essential component of the dermatology resident's training program.

Chronic cutaneous lichenoid graft-versus-host disease at the area of herpes zoster infection and at a vaccination site.

Cutaneous graft-versus-host disease (GVHD) is a frequent complication of allogeneic bone marrow transplant and haematopoietic cell transplantation, but it is rarely presented as a Wolf's isotopic response. We report a patient who developed chronic lichenoid GVHD following the dermatomes previously affected by varicella zoster virus (VZV) infection. Nineteen months later, the same patient suffered from reactivation of GVHD at the injection site of an influenza vaccination. We review the literature concerning GVHD appearing after VZV infection and discuss the possible implications of this case and the pathogenic hypotheses.

CD133+ cell content correlates with tumour growth in melanomas from skin with chronic sun-induced damage.

BACKGROUND: Melanoma is responsible for almost 80% of the deaths attributed to skin cancer. Stem cells, defined by CD133 expression, have been implicated in melanoma tumour growth, but their specific role is still uncertain. OBJECTIVES: We hypothesized that the phenotypic heterogeneity of human cutaneous melanomas is related to their content of CD133+ cells. METHODS: We compared the percentages of CD133+ cells in 29 tumours from four classic types of melanoma: lentigo maligna melanoma (LMM), superficial spreading melanoma, nodular melanoma and acral lentiginous melanoma (ALM). Also, we compared the percentages of CD133+ cells in melanomas with different degrees of exposure to ultraviolet radiation: 16 melanomas from skin with chronic sun-induced damage and 13 melanomas from skin without such damage. RESULTS: We found a statistically significant increase of CD133+ cells in three different contexts: in melanomas arising on skin with signs of chronic sun-induced damage vs. nonexposed skin, in melanomas in situ vs. invasive melanomas, and in LMM vs. ALM. The proportions of CD133+ cells did not differ among samples of normal skin with different degrees of sun exposure. A distinct subpopulation of CD133+CXCR4+ cancer stem cells (CSCs) was identified and shown to be related to the invasive phenotype of the tumours. CONCLUSIONS: Here, we provide evidence showing, for the first time, that an increase in the CD133+ cell content is associated both with melanomas arising on skin with signs of chronic sun-induced damage and in melanomas in situ with better prognosis. Moreover, our study further confirms the existence of a subpopulation of CD133+CXCR4+ CSCs in cutaneous melanomas with invasive phenotype and poor prognosis.

Clinical, molecular and biochemical characterization of nine Spanish families with Conradi-Hünermann-Happle syndrome: new insights into X-linked dominant chondrodysplasia punctata with a comprehensive review of the literature.

BACKGROUND: Conradi-Hünermann-Happle syndrome (CDPX2, OMIM 302960) is an inherited X-linked dominant variant of chondrodysplasia punctata which primarily affects the skin, bones and eyes. CDPX2 results from mutations in EBP (emopamil binding protein), and presents with increased levels of sterol precursors 8(9)-cholesterol and 8-dehydrocholesterol. OBJECTIVES: To expand the understanding of CDPX2, clinically, biochemically and genetically. METHODS: We present one of the largest series reported to date, including 13 female patients belonging to nine Spanish families. Patients were studied biochemically using gas chromatography-mass spectrometry, genetically using polymerase chain reaction and in their methylation status using the HUMARA assay. RESULTS: In our cases, there was a clear relationship between abnormal sterol profile and the EBP gene mutation. We describe three novel mutations in the EBP gene. EBP mutations were inherited in three out of nine families and were sporadic in the remaining cases. CONCLUSIONS: No clear genotype-phenotype correlation was found. Patients' biochemical profiles did not reveal a relationship between sterol profiles and severity of disease. A skewed X-chromosome inactivation may explain the clinical phenotype in CDPX2 in some familial cases.