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Background: Population-wide screening for melanoma is not cost-effective, but genetic characterization could facilitate risk stratification and targeted screening. Common Melanocortin-1 receptor (MC1R) red hair colour (RHC) variants and Microphthalmia-associated transcription factor (MITF) E318K separately confer moderate melanoma susceptibility, but their interactive effects are relatively unexplored., Objectives: To evaluate whether MC1R genotypes differentially affect melanoma risk in MITF E318K+ vs. E318K- individuals., Materials and Methods: Melanoma status (affected or unaffected) and genotype data (MC1R and MITF E318K) were collated from research cohorts (five Australian and two European). In addition, RHC genotypes from E318K+ individuals with and without melanoma were extracted from databases (The Cancer Genome Atlas and Medical Genome Research Bank, respectively). χ2 and logistic regression were used to evaluate RHC allele and genotype frequencies within E318K+/- cohorts depending on melanoma status. Replication analysis was conducted on 200 000 general-population exomes (UK Biobank)., Results: The cohort comprised 1165 MITF E318K- and 322 E318K+ individuals. In E318K- cases MC1R R and r alleles increased melanoma risk relative to wild type (wt), P < 0.001 for both. Similarly, each MC1R RHC genotype (R/R, R/r, R/wt, r/r and r/wt) increased melanoma risk relative to wt/wt (P < 0.001 for all). In E318K+ cases, R alleles increased melanoma risk relative to the wt allele [odds ratio (OR) 2.04 (95% confidence interval 1.67-2.49); P = 0.01], while the r allele risk was comparable with the wt allele [OR 0.78 (0.54-1.14) vs. 1.00, respectively]. E318K+ cases with the r/r genotype had a lower but not significant melanoma risk relative to wt/wt [OR 0.52 (0.20-1.38)]. Within the E318K+ cohort, R genotypes (R/R, R/r and R/wt) conferred a significantly higher risk compared with non-R genotypes (r/r, r/wt and wt/wt) (P < 0.001). UK Biobank data supported our findings that r did not increase melanoma risk in E318K+ individuals., Conclusions: RHC alleles/genotypes modify melanoma risk differently in MITF E318K- and E318K+ individuals. Specifically, although all RHC alleles increase risk relative to wt in E318K- individuals, only MC1R R increases melanoma risk in E318K+ individuals. Importantly, in the E318K+ cohort the MC1R r allele risk is comparable with wt. These findings could inform counselling and management for MITF E318K+ individuals., Competing Interests: Conflicts of interest H.P.S. is a shareholder of MoleMap NZ Limited and e-derm consult GmbH, and undertakes regular teledermatological reporting for both companies; he is also a Medical Consultant for Canfield Scientific Inc., Blaze Bioscience Inc., MoleMap Australia Pty Limited, and a Medical Advisor for First Derm and Revenio Research Oy. The other authors state no conflicts of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of British Association of Dermatologists.)

Study Question: Can maternal plasma cell-free DNA (cfDNA) detect chromosomal anomalies in early pregnancy loss (EPL) and recurrent pregnancy loss (RPL)?, Summary Answer: Genome-wide cfDNA testing can serve as an alternative to cytogenetic analysis in products of conception (POCs) in RPLs and can guide further management., What Is Known Already: Random chromosomal anomalies are the single most common cause for EPL and RPL. Cytogenetic analysis in POCs may be used to direct management in RPL because the detection of random chromosomal anomalies can eliminate further unwarranted testing., Study Design, Size, Duration: This was a prospective diagnostic test study from March 2018 to January 2019 of 109 patients experiencing pregnancy loss before 14 weeks gestation at a tertiary-care academic medical center., Participants/materials, Setting, Methods: Blood samples were drawn for genome-wide cfDNA testing prior to chorionic villous sampling for cytogenetic analysis of POCs with both short-term cultures (STCs) and long-term cultures (LTCs). Final analysis included 86 patients with non-mosaic cytogenetic results in POCs and available cfDNA results. Aneuploidy detection rates by cfDNA testing and POC cytogenetic analysis were compared. The first 50 samples served as the Training Set to establish pregnancy loss-specific log-likelihood ratio (LLR) thresholds using receiver-operator characteristic (ROC)-like analyses. These were then used for the entire cohort., Main Results and the Role of Chance: Seventy-eight samples (71.5%) had results available from both STC and LTC; 12 samples (11%) had a result from STC only, and 7 samples (6.4%) had a result from LTC only. A chromosomal anomaly was detected in 55/86 (64%). The rates of chromosomal anomalies were 61, 72, 73 and 44% in patients undergoing their first, second, third and ≥4th pregnancy losses, respectively. The median cfDNA fetal fraction was 5%. With standard LLR thresholds used for noninvasive prenatal screening, the sensitivity of cfDNA in detecting aneuploidy was 55% (30/55) and with a specificity of 100% (31/31). Using pregnancy loss-specific LLR thresholds, the sensitivity of cfDNA in detecting aneuploidy was 82% (45/55), with a specificity of 90% (28/31). The positive and negative likelihood ratios were 8.46 and 0.20, respectively. Fetal sex was correctly assigned in all cases., Limitations, Reasons for Caution: Cases with a false-positive result by cfDNA analysis would not receive the indicated RPL workup. Specificity could be improved by using a fetal fraction (FF) cutoff of 4%, but this would result in exclusion of more than a quarter of cases., Wider Implications of the Findings: cfDNA-based testing can serve as an alternative to POC cytogenetic analysis and can guide further RPL management: if cfDNA demonstrates aneuploidy, no further action is taken and if no abnormality is detected, the recommended RPL workup is performed., Study Funding/competing Interest(s): Cell-free DNA testing was funded by Illumina, Inc., San Diego, CA. Y.Y. is a member of Illumina's Clinical Expert Panel and has received travel grants. A.B. has received travel grants from Illumina. All authors have no competing interest to declare., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.)

Background: Germline mutations in telomere-related genes such as POT1 and TERT predispose individuals to familial melanoma., Objectives: To evaluate the prevalence of germline mutations in POT1 and TERT in a large cohort of Spanish melanoma-prone families (at least two affected first- or second-degree relatives)., Methods: Overall, 228 CDKN2A wild-type melanoma-prone families were included in the study. Screening of POT1 was performed in one affected person from each family and TERT was sequenced in one affected patient from 202 families (26 families were excluded owing to DNA exhaustion/degradation). TERT promoter sequencing was extended to an additional 30 families with CDKN2A mutation and 70 patients with sporadic multiple primary melanoma (MPM) with a family history of other cancers., Results: We identified four families with potentially pathogenic POT1 germline mutations: a missense variant c.233T>C (p.Ile78Thr); a nonsense variant c.1030G>T (p.Glu344*); and two other variants, c.255G>A (r.125&#95;255del) and c.1792G>A (r.1791&#95;1792insAGTA, p.Asp598Serfs*22), which we confirmed disrupted POT1 mRNA splicing. A TERT promoter variant of unknown significance (c.-125C>A) was detected in a patient with MPM, but no germline mutations were detected in TERT promoter in cases of familial melanoma., Conclusions: Overall, 1·7% of our CDKN2A/CDK4-wild type Spanish melanoma-prone families carry probably damaging mutations in POT1. The frequency of TERT promoter germline mutations in families with melanoma in our population is extremely rare., (© 2018 British Association of Dermatologists.)

Congenital erythropoietic porphyria is a rare autosomal recessive disease caused by a deficiency of uroporphyrinogen III synthase, owing to mutations in UROS in chromosome 10. Occasionally, patients show a mild, late-onset disease, without germline UROS mutations, associated with haematological malignancies. We report a 65-year-old patient with photosensitivity, overexcretion of porphyrins and thrombocytopenia. Bone marrow analysis gave a diagnosis of myelodysplastic syndrome (MDS) with the presence of a derivative chromosome 3, possibly due to an inversion including 3q21 and 3q26 break points. After allogeneic stem-cell transplantation, complete remission of MDS and uroporphyria was achieved. To our knowledge, this is the first reported case of acquired erythropoietic uroporphyria associated with MDS, with chromosome 3 alterations., (© 2017 British Association of Dermatologists.)

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., (© 2017 British Association of Dermatologists.)

Background: Nearly 10% of all cases of cutaneous melanoma (CM) occur in patients with a personal or family history of the disease., Objectives: To obtain information about genetic predisposition to CM in Ticino, the southern region of Switzerland, a zone with moderate-to-high CM incidence., Methods: We identified germline mutations in highly CM-associated genes (CDKN2A and CDK4) and low/medium-penetrance variants (MC1R and MITF) in patients with multiple primary CMs or individuals with one or more CM and a positive family history for CM or pancreatic cancer among first- or second-degree relatives. Healthy blood donors (n = 146) were included as a control group., Results: From July 2010 to July 2012, 57 patients (41 pedigrees) were included. Twenty-six were melanoma-prone families (with at least two cases) and 15 had multiple CMs. Pancreatic cancer was found in six families. The CDKN2A mutation p.V126D was identified in seven patients (four families) with a founder effect, whereas CDKN2A A148T was detected in seven cases (five families) and seven healthy donors (odds ratio 2·76, 95% confidence interval 0·83-9·20). At least one MC1R melanoma-associated polymorphism was detected in 32 patients (78%) and 97 healthy donors (66%), with more than one polymorphism in 12 patients (29%) and 25 healthy donors (17%). The MITF variant p.E318K was identified in four patients from three additional pedigrees (7%) and one healthy control (0·7%)., Conclusions: Inclusion criteria for the Ticino population for genetic assessment should follow the rule of two (two affected individuals in a family or a patient with multiple CMs), as we detected a CDKN2A mutation in almost 10% of our pedigrees (four of 41), MITF p.E318K in 7% (three of 41) and a higher number of MC1R variants than in the control population., (© 2016 British Association of Dermatologists.)

Background: The origin of melanoma has always been a debated subject, as well as the role of adjacent melanocytic naevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a naevus., Objectives: To evaluate the presence of mutations in genes from well-known melanomagenesis pathways in a large series of naevus-associated melanomas., Materials and Methods: Sixty-one melanomas found in association with a pre-existing naevus were microdissected, after careful selection of cell subpopulations, and submitted to Sanger sequencing of the BRAF, NRAS, c-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection or by SNaPshot analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive., Results: The majority of cases presented concordance of mutational status between melanoma and the associated naevus for all six genes (40 of 60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case in which both the melanoma and the adjacent naevus harboured V600E and Q61K double mutations. In two cases, both melanoma and associated naevus located on acral sites were BRAF mutated, including an acral lentiginous melanoma., Conclusions: To our knowledge this is the largest naevus-associated melanoma series evaluated molecularly. The majority of melanomas and adjacent naevi in our sample share the same mutational profile, corroborating the theory that the adjacent naevus and melanoma are clonally related and that the melanoma originated within a naevus., (© 2015 British Association of Dermatologists.)

Background: The identification of BRAF mutations in melanoma led to the development and implementation of new and effective therapies. Few clinical and histological features have been associated with this mutational status., Objectives: The main objective of this study was to investigate clinical, histopathological and dermoscopic characteristics of primary melanomas according to BRAF or NRAS mutational status., Methods: An observational retrospective study including melanoma dermoscopy images assessed for somatic mutations in BRAF and NRAS., Results: Seventy-two patients were included, 30 women (42%) and 42 men (58%), mean age was 59 ± 15.51 years. BRAF-mutated melanomas were more frequently located on the trunk (n = 18, 64% for BRAF-mutated vs. n = 11, 29% for wild-type melanomas, P = 0.013). Histological ulceration was associated with the presence of BRAF mutations [odds ratio (OR) 3.141; 95% confidence interval (CI) 1.289-7.655; P = 0.002]. The Breslow index tended to be thicker in BRAF-mutated compared with wild-type (P = 0.086). BRAF mutations were present in 28 (39%) patients and only four cases were positive for NRAS mutations (6%), BRAF and NRAS mutations being mutually exclusive. The presence of dermoscopic peppering was associated with MAPK mutations (BRAF and NRAS) (OR 1.68; 95% CI 1.089-2.581; P = 0.015). Dermoscopic ulceration was also associated with BRAF mutations excluding acral and facial melanomas (OR 2.64; 95% CI 1.032-6.754)., Conclusions: This study showed a correlation between BRAF and NRAS status and dermoscopic findings of 'peppering' as an expression of regression and melanophages in the dermis, suggesting a morphological consequence of immune behaviour in BRAF-mutated melanomas., (© 2014 British Association of Dermatologists.)

Background: Recently, TERT promoter mutations were identified at high frequencies in cutaneous melanoma tumor samples and cell lines. The mutations were found to have a UV-signature and to lead to increased TERT gene expression. We analyzed a large cohort of melanoma patients for the presence and distribution of TERT promoter mutations and their association with clinico-pathological characteristics., Methods: 410 melanoma tumor samples were analyzed by Sanger sequencing for the presence of TERT promoter mutations. An analysis of associations between mutation status and various clinical and pathologic variables was performed., Results: TERT promoter mutations were identified in 154 (43%) of 362 successfully sequenced melanomas. Mutation frequencies varied between melanoma subtype, being most frequent in melanomas arising in nonacral skin (48%) and melanomas with occult primary (50%), and less frequent in mucosal (23%), and acral (19%) melanomas. Mutations carried a UV signature (C>T or CC>TT). The presence of TERT promoter mutations was associated with factors such as BRAF or NRAS mutation (P < .001), histologic type (P = .002), and Breslow thickness (P < .001). TERT promoter mutation was independently associated with poorer overall survival in patients with nonacral cutaneous melanomas (median survival 80 months vs 291 months for wild-type; hazard ratio corrected for other covariates 2.47; 95% confidence interval [CI] = 1.29 to 4.74; P = .006)., Conclusions: UV-induced TERT promoter mutations are one of the most frequent genetic alterations in melanoma, with frequencies varying depending on melanoma subtype. In nonacral cutaneous melanomas, presence of TERT promoter mutations is independently associated with poor prognosis., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Background: Cutaneous melanoma tumour is classified into clinicohistopathological subtypes that may be associated with different genetic and host factors. Variation in the MC1R gene is one of the main factors of risk variation in sporadic melanoma. The relationship between MC1R variants and the risk of developing a specific subtype of melanoma has not been previously explored., Objectives: To analyse whether certain MC1R variants are associated with particular melanoma subtypes with specific clinicohistopathological features., Methods: An association study was performed between MC1R gene variants and clinicopathological subtypes of primary melanoma derived from 1679 patients., Results: We detected 53 MC1R variants (11 synonymous and 42 nonsynonymous). Recurrent nonsynonymous variants were p.V60L (30·0%), p.V92M (11·7%), p.D294H (9·4%), p.R151C (8·8%), p.R160W (6·2%), p.R163Q (4·2%) p.R142H (3·3%), p.I155T (3·8%), p.V122M (1·5%) and p.D84E (1·0%). Melanoma subtypes showed differences in the total number of MC1R variants (P = 0·028) and the number of red hair colour variants (P = 0·035). Furthermore, an association between p.R163Q and lentigo maligna melanoma was detected under a dominant model of heritance (odds ratio 2·16, 95% confidence interval 1·07-4·37; P = 0·044). No association was found between p.R163Q and Fitzpatrick skin phototype, eye colour or skin colour, indicating that the association was independent of the role of MC1R in pigmentation. No association was observed between MC1R polymorphisms and other melanoma subtypes., Conclusions: Our findings suggest that certain MC1R variants could increase melanoma risk due to their impact on pathways other than pigmentation, and may therefore be linked to specific melanoma subtypes., (© 2013 British Association of Dermatologists.)

Background: A series of studies has investigated epidemiological, clinical and genetic characteristics of patients with multiple primary melanoma (MPM). However, comparison of the clinical and dermoscopic features of MPM within a given individual has been described only in case reports., Objectives: To describe the dermoscopic features of MPM for each given patient, and to evaluate the characteristics eventually associated with similar or dissimilar appearance., Methods: From the databases of three skin-lesion clinics in the U.S.A., Italy and Spain we collected the dermoscopic images of melanomas in patients diagnosed with MPM., Results: Among 58 patients with MPM, we found that 53% of patients had dermoscopically similar melanomas and 47% of patients had dermoscopically different melanomas. In older patients 59% of melanomas were dermoscopically similar vs. 47% in younger patients (P=0·377). Similar thickness was associated with the occurrence of dermoscopically similar melanomas (19/30 cases, 63%; P=0·039). Most (65%) of the synchronous lesions were similar, compared with 36% of nonsynchronous lesions (P=0·029), and most (69%) of the melanomas on sun-damaged skin were similar, vs. 37% of melanomas on nonsun-damaged skin (P=0·015; odds ratio 3·88, 95% confidence interval 1·11-13·98). The percentage of dermoscopically different melanomas was higher in patients with a family history of melanoma (67% vs. 48%)., Conclusions: MPMs in a given patient have almost the same chance of looking dermoscopically similar or different. However, a subset of elderly patients with sun-damaged skin may present multiple, similar, thin melanomas characterized by pigment-network and regression structures., (© 2013 The Authors. BJD © 2013 British Association of Dermatologists.)

Background: Hepatoerythropoietic porphyria (HEP) is a rare form of porphyria that results from a deficiency of uroporphyrinogen decarboxylase (UROD). The disease is caused by homoallelism or heteroallelism for mutations in the UROD gene., Objective: To study a 19-year-old woman from Equatorial Guinea, one of the few cases of HEP of African descent and to characterize a new mutation causing HEP., Methods: Excretion of porphyrins and residual UROD activity in erythrocytes were measured and compared with those of other patients with HEP. The UROD gene of the proband was sequenced and a new mutation identified. The recombinant UROD protein was purified and assayed for enzymatic activity. The change of amino acid mapped to the UROD protein and the functional consequences were predicted., Results: The patient presented a novel homozygous G170D missense mutation. Porphyrin excretion showed an atypical pattern in stool with a high pentaporphyrin III to isocoproporphyrin ratio. Erythrocyte UROD activity was 42% of normal and higher than the activity found in patients with HEP with a G281E mutation. The recombinant UROD protein showed a relative activity of 17% and 60% of wild-type to uroporphyrinogen I and III respectively. Molecular modelling showed that glycine 170 is located on the dimer interface of UROD, in a loop containing residues 167-172 that are critical for optimal enzymatic activity and that the carboxyl side chain from aspartic acid is predicted to cause negative interactions between the protein and the substrate., Conclusions: The results emphasize the complex relationship between the genetic defects and the biochemical phenotype in homozygous porphyria., (© 2011 The Authors. BJD © 2011 British Association of Dermatologists.)

Objective: To determine the prognostic value of detecting tyrosinase transcripts in melanoma sentinel lymph nodes (SLNs)., Methods: Reverse transcription (RT) PCR for tyrosinase mRNA was performed on negative SLNs of 76 patients with melanoma., Results: Tyrosinase mRNA was found in 39 patients (51.3%). After a median follow-up period of 51 months, significant differences were found in overall survival (OS) but not in disease-free survival (DFS). The 5-year OS and DFS rates were 97.2% and 80%, respectively, for RT-PCR tyrosinase-negative (TN) patients vs. 78.67% and 66.24% for RT-PCR tyrosinase-positive (TP) patients (P = 0.019 and P = 0.38, respectively). Of four progressing patients in the TN group, three relapsed with subcutaneous, soft-tissue or lymph-node metastases, while seven out of nine progressing patients in the TP group relapsed at visceral sites., Conclusions: No significant differences in DFS were found by RT-PCR tyrosinase expression analysis at melanoma SLNs. Significant differences in OS could be related to a different pattern of relapse and must be confirmed after a longer follow-up time.

Background: Familial melanoma, a cluster of several cases within a single family, accounts for approximately 10% of cases of melanoma. Hereditary melanoma is defined as two or more first-degree relatives having melanoma. A member of a melanoma-prone family has a 35-70-fold increased relative risk of developing a melanoma. Genetic susceptibility is linked to the major susceptibility genes CDKN2A and CDK4, and the minor susceptibility gene MC1R., Objectives: To determine the clinical and genetic characteristics of cutaneous melanoma in melanoma-prone families from Uruguay., Methods: We studied 13 individuals from six melanoma-prone families living in Uruguay. Phenotype, familial and personal history were recorded. Molecular screening of CDKN2A and CDK4 was done by polymerase chain reaction-single strand conformational polymorphism analysis. The MC1R gene was sequenced., Results: Mutations in CDKN2A were detected in five of six families: c.-34G>T, p.G101W and p.E88X. A novel germline mutation p.E88X, associated with hereditary melanoma in two unrelated families, is described. We hypothesize that a founder effect occurred probably in the Mediterranean region. No mutations in CDK4 were detected. Six different MC1R variants, all previously reported, were present in Uruguayan families., Conclusions: The overall rate of deleterious CDKN2A mutations in our familial melanoma pedigrees, even though the sample size is small, was considerably higher (83%) than the often quoted range.

Background: The presence of at least one MC1R gene variant is associated with a reduction in age at melanoma diagnosis in families with CDKN2A mutations., Objectives: To describe dermoscopic features of early melanoma in CDKN2A gene mutation-positive Spanish individuals and to evaluate the possibility of a correlation between particular dermatoscopic pattern and MC1R gene variants., Methods: Patients in whom a melanoma was diagnosed during specific follow up of high-risk individuals carrying CDKN2A mutations (with familial or personal history of previous melanoma) were included in this study. The decision to remove such melanomas was taken on the basis of history, clinical and dermoscopic evaluations including total body photography and digital dermoscopy., Results: Of the nine patients included in this study, three were noncarriers of the red hair MC1R polymorphism, three patients had one red hair MC1R polymorphism and three patients had two red hair MC1R polymorphisms. On dermoscopic analysis of suspect melanocytic lesions we found that the mean +/- SD ABCD total dermoscopy score (TDS) was significantly higher in noncarriers of red hair MC1R polymorphisms than in carriers of two MC1R gene red hair variants (6.8 +/- 0.4 vs. 4.4 +/- 0.9; P = 0.014)., Conclusions: Early melanomas in patients with two MC1R red hair variants may be difficult to diagnose definitively by dermoscopy because, in our limited experience, they show fewer colours and structures and have a lower TDS. In such melanomas, subtle atypical vessels and other changes detected by digital image follow up may be useful to confirm the diagnosis of melanoma. An integrated approach including clinical history and dermoscopic data (also considering additional information, such as the presence of atypical vessels) should be utilized in evaluating these high-risk patients. Further studies are necessary to confirm our suggestion.

Three children (two boys and one girl) from the same family presented with photosensitivity, hyperpigmentation, hypertrichosis, mild skin fragility, blistering and scarring in childhood. On examination, the cutaneous lesions were found to have improved since their previous examinations. Laboratory tests showed raised plasma and urine carboxyporphyrins and decreased uroporphyrinogen decarboxylase enzyme activity in red blood cells. Triggering factors for porphyria were not detected except for a hepatitis C virus infection in the younger boy. The girl's clinical symptoms recurred in late adolescence, after iron and oestrogen treatments. Mutation analysis of the UROD gene detected two missense mutations, 19 A-->G M1V (novel) and 703C-->T P235S (previously reported), in an uncommon compound heterozygous manner in the three siblings.

Background: The p33ING1b gene is involved in the p53-dependent response to DNA damage following exposure to ultraviolet radiation, and has recently been reported to be mutated in 20% of melanoma tumours., Objectives: We sought to assess the p33ING1b mutation rate in our large panels of fresh melanomas and melanoma cell lines., Methods: We screened 83 primary melanomas and 55 melanoma cell lines for mutations in p33ING1b by single-strand conformational polymorphism analysis and by direct sequencing., Results: In contrast to previous reports, we found no somatic p33ING1b mutations in our panel of melanomas. We found that some of the discrepancy between our results and previously published studies may be due to inadvertent amplification of the ING1 pseudogene (INGX), and/or contamination of some samples with murine Ing1., Conclusions: p33ING1b mutations in melanoma are rare. We have highlighted the importance of allele-specific primer design to avoid pseudogene amplification, and also the necessity to confirm the genetic identity and species of origin of individual cell lines. Further studies are needed to clarify the possible role of p33ING1b in melanoma tumorigenesis.

Background: To study the sonographic pattern of autosomal recessive polycystic kidney disease (ARPKD) in early adulthood in order to identify imaging criteria to diagnose this disease and to distinguish between recessive and autosomal dominant polycystic kidney disease (ADPKD) in that age group., Methods: An abdominal ultrasound was performed on four ARPKD subjects (with a mean age of 20.2) and on 33 ADPKD subjects in early adulthood (29 without renal failure with a mean age of 20.5, and four with renal failure with a mean age of 26.5). Linkage studies with ADPKD and ARPKD markers were compatible with the clinical diagnosis in all cases., Results: The renal sonographic features in ARPKD subjects included multiple small cysts in a normal-sized kidney, increased cortical echogenicity and loss of corticomedullary differentiation. In ADPKD subjects without renal failure, sonographic features included few or multiple cysts of different sizes, in normal-sized kidneys in 22 out of 29 patients (75.8%), normal cortical echogenicity and conserved corticomedullary differentiation, except in patients with nephromegaly. All ADPKD subjects with renal failure had nephromegaly and loss of corticomedullary differentiation. The hepatic sonographic features in ARPKD patients included portal fibrosis and in some cases Caroli's disease, while in ADPKD patients a normal hepatic echostructure was detected in all but one case, in addition to simple hepatic cysts in a few cases., Conclusions: The evaluation of the sonographic features of the kidneys and those of the liver may help in the differential diagnosis between ARPKD and ADPKD in early adulthood.

Background: Genetic heterogeneity is a well-known feature of Alport syndrome (AS). Most families with AS show an X-linked dominant pattern of inheritance but about 15% of families show an autosomal inheritance of the disease. Autosomal recessive AS may account for 10% of the total number of cases and is caused by mutations in the COL4A3 and COL4A4 genes. The clinical spectrum of this rare disorder has not been well clarified., Methods: We present two families with AS. Two affected members of these families have entered end-stage renal disease (ESRD) in their 30s, and the other three are older than 15 years and have normal serum creatinine. Four of the five patients have deafness but none have ocular abnormalities. Two have been transplanted and have not suffered from anti-GBM antibody nephritis. Men and women are equally affected. We have performed linkage analysis for chromosome 2 with the following markers: D2S279, COL4A3/4 DNTR, COL4A4 RFLP Hae III., Results: We demonstrate that both families, one of them consanguineous, are linked to the COL4A3/4 locus., Conclusions: We can conclude that the only significant difference between the X-linked and the autosomal recessive forms of AS lies in the fact that in the latter females are as affected as males; thus the idea that autosomal recessive AS causes ESRD during childhood must be discarded. Other clinical features such as age of deafness or the presence of post-transplant anti-GBM antibody nephritis show no differences between the entities. Thus an accurate familial study is mandatory in patients with AS, as the identification of the different patterns of inheritance may cause a great difference in genetic counselling. Linkage analysis is the only effective molecular diagnosis that can be performed nowadays.