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Co-Occurring EGFR L858R Mutation and HER2 Amplification in NSCLC Identified by Stepwise Molecular Profiling.

BACKGROUND The coexistence of multiple oncogenic drivers in non-small cell lung cancer (NSCLC) is a rare and diagnostically challenging molecular configuration. Conventional polymerase chain reaction (PCR)-based testing may fail to detect co-occurring genomic alterations, potentially limiting therapeutic options, particularly in resource-constrained settings. CASE REPORT We describe the case of a 54-year-old non-smoking woman diagnosed with Stage IIIA lung adenocarcinoma in 2020. Initial PCR-based molecular testing was negative for EGFR mutations. Following disease progression with brain metastases and severe chemotherapy toxicity, stepwise molecular profiling in a resource-limited setting identified HER2 (ERBB2) amplification via fluorescence in situ hybridization (FISH). The patient achieved 23 months of clinical and radiological stabilization on trastuzumab. Subsequent next-generation sequencing (NGS) analysis of archived tissue revealed a previously undetected estimated glomular filtration rate (EGFR) L858R mutation. In late April 2025, new lesions appeared in the lungs, indicating disease progression. Based on the previously verified EGFR L858R mutation, the treatment strategy was revised and gefitinib was initiated in May 2025. CONCLUSIONS This case illustrates that co-occurring EGFR and HER2 alterations can remain undetected following initial limited molecular testing, and that stepwise molecular profiling in a resource-constrained setting can facilitate identification of therapeutically actionable targets. The sequential clinical responses observed are consistent with the biological relevance of both alterations, although broader conclusions regarding diagnostic strategy or driver hierarchy cannot be drawn from a single observation.

Humans↗

ZAP-70 expression identifies a chronic lymphocytic leukemia subtype with unmutated immunoglobulin genes, inferior clinical outcome, and distinct gene expression profile.

The presence or absence of somatic mutations in the expressed immunoglobulin heavy chain variable regions (IgVH) of chronic lymphocytic leukemia (CLL) cells provides prognostic information. Patients whose leukemic cells express unmutated IgVH regions (Ig-unmutated CLL) often have progressive disease, whereas patients whose leukemic cells express mutated IgVH regions (Ig-mutated CLL) more often have an indolent disease. Given the difficulty in performing IgVH sequencing in a routine diagnostic laboratory, this prognostic distinction is currently unavailable to most patients. Pilot gene expression profiling studies in patients with CLL identified genes that were differentially expressed between the Ig-unmutated and Ig-mutated CLL subtypes. Here, we have profiled an expanded cohort of 107 patients and show that ZAP-70 is the gene that best distinguishes the CLL subtypes. Ig-unmutated CLL expressed ZAP-70 5.54-fold more highly than Ig-mutated CLL (P < 10(-21)). ZAP-70 expression correctly predicted IgVH mutation status in 93% of patients. ZAP-70 expression and IgVH mutation status were comparable in their ability to predict time to treatment requirement following diagnosis. In 7 patients, ZAP-70 expression and IgVH mutation status were discordant: 4 Ig-mutated CLLs had high ZAP-70 expression and 3 Ig-unmutated CLLs had low ZAP-70 expression. Among these ZAP-70 "outliers," those with Ig-mutated CLL had clinical features that are uncharacteristic of this CLL subtype: 2 required early treatment and 2 used a mutated VH3-21 gene, an IgVH gene that has been associated with progressive disease. We developed reverse transcriptase-polymerase chain reaction and immunohistochemical assays for ZAP-70 expression that can be applied clinically and would yield important prognostic information for patients with CLL.

ADP-ribosyl Cyclase↗

HIV-1 reverse transcriptase and protease resistance mutations selected during 16-72 weeks of therapy in isolates from antiretroviral therapy-experienced patients receiving abacavir/efavirenz/amprenavir in the CNA2007 study.

OBJECTIVE: To determine HIV-1 reverse transcriptase (RT) and protease (PRO) mutations selected in isolates from antiretroviral therapy (ART)-experienced patients receiving an efavirenz/abacavir/amprenavir salvage regimen. METHODS: Open-label, single arm of abacavir, 300 mg twice daily, amprenavir, 1200 mg twice daily and efavirenz, 600 mg once daily, in ART-experienced patients of which 42% were non-nucleoside reverse transcriptase inhibitor-naive. The virology population examined consisted of all patients who took at least 16 weeks of study drugs (n=74). Plasma population sequencing was carried out at baseline and last time point at which patients were still taking the three study drugs + other ART. The median follow-up was 48 weeks (range week 16-72). RESULTS: Baseline (n=73) and on-therapy (n=49) genotypes were obtained. By 48 weeks, 51% of isolates had > or = 3 non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations. NNRTI mutations selected on therapy were K103N (51%), substitutions at position 190 (17/49, 35%): G to A (n=11) / S (n=4) / E (n=1) and T (n=1); L100I (37%) and V1081 (20%) mutations. P225H was not observed in this study. L100I and G190A/S/E/T mutations were rarely detected in the same viral population and baseline Y181C favoured the G190 mutations (OR=8.9, P<0.001), rather than the L100I. The NRTI mutations selected were in accordance with abacavir known resistance profile, no new TAMs were observed, new L74V or I mutations developed in 39 and 16% of isolates, respectively, however, new M184V mutations were only detected in isolates from two patients, one of whom had added lamivudine + didanosine. M184V was common at baseline (55%) and maintained in 22/27 (81%) isolates (five of these 22 added lamivudine or didanosine, or both). The PRO mutations selected were in accordance with the distinct resistance profile of amprenavir compared with other protease inhibitors. Mutations D30N, G48V, N88D/S, L90M and 154V were de-selected, and mutations I50V, I or V to 54M/L, I84V, M46I/L, L33F, I47V as well mutations at position 10 were observed in 20/49 (41%) isolates. CONCLUSION: Prior NNRTI and NRTI therapy influences the pathway of resistance to efavirenz. In this study, the prevalence of mutations selected by efavirenz were different from those described in less ART-experienced patients. Baseline Y181C was associated with the development of mutations at position 190, but not L100I or K103N. In this patient population, abacavir with efavirenz preferentially selected for L74V but not for thymidine analogue mutations. M184V was rarely selected and was maintained in only 77% of patients who did not add lamivudine or didanosine. Finally, amprenavir-specific mutations were selected in the background of other primary protease inhibitor mutations, confirming the distinct resistance profile of amprenavir.

Alkynes↗

ilvU, a locus in Escherichia coli affecting the derepression of isoleucyl-tRNA synthetase and the RPC-5 chromatographic profiles of tRNAIle and tRNAVal.

A mutation in the ilvU locus of Escherichia coli has led to a complex phenotype that included resistance to thiaisoleucine, a loss of derepressibility of isoleucyl tRNA synthetase, and an alteration of the RPC-5 chromatographic profile of the branched-chain aminoacyl-tRNA's. The alterations were manifest in an increase in the amount of Species 2 of both tRNAIle and tRNAVal at the expense of Species 1. A similar alteration, but independent of (and additive to) that caused by the ilvU mutation, was observed upon limitation of either isoleucine or valine. The shift in profile caused by limitation was also independent of the reduced growth rate or the derepression of the isoleucine and valine biosynthetic enzymes that also result from limitation. During chloramphenicol treatment nearly all tRNAIle and tRNAVal formed appears as species 2. Upon recovery from chloramphenicol, Species 2 of both acceptors are converted to Species 1. It is proposed that the ilvU product not only allows derepression of isoleucyl-tRNA synthetase but also retards the conversion of tRNA2Ile to tRNA1Ile and that of tRNA2Val to tRNA1Val. The mutated ilvU loci abolish the derepression and are more efficient in retarding the conversion.

Amino Acyl-tRNA Synthetases↗

A PMS2-deficient pediatric high-grade glioma with PI3K-pathway mutations and adjacent developmental venous anomaly suggestive of CMMRD.

PURPOSE: Constitutional mismatch repair deficiency (CMMRD) is a rare hereditary cancer predisposition syndrome that frequently manifests with pediatric high-grade gliomas. However, recognition remains challenging, particularly in the absence of a clear family history. We report a pediatric high-grade glioma with PMS2 deficiency and complex molecular alterations to highlight key diagnostic clues and the importance of routine mismatch repair assessment. METHODS: Clinical, radiological, histopathological, immunohistochemical, and molecular findings of an 8-year-old girl presenting with a high-grade glioma were retrospectively evaluated. Immunohistochemistry included glial and mismatch repair markers. Targeted next-generation sequencing was performed to assess tumor mutational burden and pathogenic variants. RESULTS: Neuroimaging revealed a right frontoparietal mass associated with an adjacent developmental venous anomaly. Histopathology demonstrated a diffuse pediatric-type high-grade glioma with pseudopapillary architecture and marked mitotic activity. Immunohistochemistry showed diffuse p53 overexpression in tumor cells and complete loss of PMS2 expression in both tumor and non-neoplastic cells, supporting constitutional mismatch repair deficiency. Molecular analysis revealed an ultra-hypermutated profile with a tumor mutational burden of 117.4 mutations/Mb, a pathogenic PMS2 frameshift variant, and co-occurring alterations in TP53, PIK3CA, PIK3R1, and PTEN. The presence of PI3K-pathway mutations alongside a venous anomaly suggested a potential biological association. CONCLUSION: This case illustrates the characteristic clinicopathological and molecular features of CMMRD-associated pediatric high-grade glioma and underscores the critical role of routine mismatch repair immunohistochemistry. Integrated histological and genomic evaluation is essential for accurate diagnosis, appropriate genetic counseling, and potential therapeutic implications. Key Points &#x2022;&#xa0;This case represents a pediatric high-grade glioma arising in the setting of PMS2-related constitutional mismatch repair deficiency (CMMRD). &#x2022; The tumor exhibited an ultra-hypermutated profile with co-occurring TP53, PIK3CA, PIK3R1, and PTEN mutations. &#x2022; Loss of PMS2 expression in both tumor and non-neoplastic cells was critical in establishing the diagnosis of CMMRD. &#x2022; The presence of a developmental venous anomaly may relate to underlying PIK3R1 pathway alterations. &#x2022; Routine mismatch repair immunohistochemistry is essential in pediatric high-grade gliomas, even in the absence of a family history.

Humans↗

TEM beta-lactamase mutants hydrolysing third-generation cephalosporins. A kinetic and molecular modelling analysis.

The catalytic properties of six "natural" mutants of the TEM-1 beta-lactamase have been studied in detail, with special emphasis on their activity versus third-generation cephalosporins. On the basis of the recently determined high-resolution structure of the wild-type enzyme, and of the substrates' structures optimized by the AMI quantum chemistry method, we have attempted to explain the influences of the mutations on the substrate profiles of the enzymes. Some of the kinetic results have thus received a satisfactory, semi-quantitative interpretation, especially in the case of single mutations. Analysis of the double mutants proved more hazardous. Extending the comparison to some other class A beta-lactamases showed that similar properties could result from different sequences, supplying an interesting example of convergent evolution within a generally diverging family.

Aztreonam↗

Multiple CYP1B1 mutations and incomplete penetrance in an inbred population segregating primary congenital glaucoma suggest frequent de novo events and a dominant modifier locus.

Primary congenital glaucoma (PCG) is an autosomal recessive disorder associated with unknown developmental defect(s) in the anterior chamber. Recently, we reported three distinct mutations in CYP1B1, the gene for cytochrome P4501B1, in 25 Saudi families segregating PCG. For this report, we analyzed 37 additional families and confirmed the initial finding of decreased penetrance. Mutations and intragenic single-nucleotide polymorphisms (SNPs) were also analyzed from direct sequencing of all CYP1B1 coding exons. Eight distinct mutations were identified: G61E, R469W and D374N, the most common Saudi mutations, account for 72, 12 and 7%, respectively, of all the PCG chromosomes. Five additional homozygous mutations (two deletions and three missense mutations) were detected, each in a single family. Affected individuals from five families had no CYP1B1 coding mutations, and each family had a unique SNP profile. The identification of eight distinct mutations in a single gene, on four distinct haplotypes, suggests a relatively recent occurrence of multiple mutations in CYP1B1 in Saudi Arabia. These data demonstrate decreased penetrance of the PCG phenotype in the Saudi population, because 40 apparently unaffected individuals in 22 families have mutations and haplotypes identical to their affected siblings. Two individuals were subsequently diagnosed with glaucoma and two others had abnormal ocular findings that are consistent with milder forms of glaucoma. Analysis of these 22 kindreds suggests the presence of a dominant modifier locus that is not linked genetically to CYP1B1. Linkage and Southern analyses excluded three candidate modifier loci.

Amino Acid Sequence↗

Alteration of alpha 1 Na+,K(+)-ATPase 86Rb+ influx by a single amino acid substitution.

The sodium- and potassium-dependent adenosine triphosphatase (Na+,K(+)-ATPase) maintains the transmembrane Na+ gradient to which is coupled all active cellular transport systems. The R and S alleles of the gene encoding the Na+,K(+)-ATPase alpha 1 subunit isoform were identified in Dahl salt-resistant (DR) and Dahl salt-sensitive (DS) rats, respectively. Characterization of the S allele-specific Na+,K(+)-ATPase alpha 1 complementary DNA identified a leucine substitution of glutamine at position 276. This mutation alters the hydropathy profile of a region in proximity to T3(Na), the trypsin-sensitive site that is only detected in the presence of Na+. This mutation causes a decrease in the rubidium-86 influx of S allele-specific sodium pumps, thus marking a domain in the Na+,K(+)-ATPase alpha subunit important for K+ transport, and supporting the hypothesis of a putative role of these pumps in hypertension.

Amino Acid Sequence↗

DHPLC analysis of the MECP2 gene in Italian Rett patients.

Rett Syndrome (RTT) is an X-linked dominant neurodevelopmental disorder, which almost exclusively affects girls, with an estimated prevalence of one in 10,000-15,000 female births. Mutations in the methyl CpG binding protein 2 gene (MECP2) have been identified in roughly 75% of classical Rett girls. The vast majority of Rett cases (99%) are sporadic in origin, and are due to de novo mutations. We collected DNA samples from 50 Italian classical Rett girls, and screened the MECP2 coding region for mutations by denaturing high-performance liquid chromatography (DHPLC) and subsequent direct sequencing. DHPLC is a recently developed method for mutation screening which identifies heteroduplexes formed in DNA samples containing mismatches between wild type and mutant DNA strands, combining high sensitivity, reduced cost per run, and high throughput. In our series, 19 different de novo MECP2 mutations, eight of which were previously unreported, were found in 35 out of 50 Rett girls (70%). Seven recurrent mutations were characterized in a total of 22 unrelated cases. Initial DHPLC screening allowed the identification of 17 out of 19 different mutations (90%); after optimal conditions were established, this figure increased to 100%, with all recurrent MECP2 mutations generating a characteristic chromatographic profile. Detailed clinical data were available for 27 out of 35 mutation carrying Rett girls. Milder disease was detectable in patients carrying nonsense mutation as compared to patients carrying missense mutations, although this difference was not statistically significant (P = 0.077).

Chromatography, High Pressure Liquid↗

Effect of apolipoprotein E, peroxisome proliferator-activated receptor alpha and lipoprotein lipase gene mutations on the ability of fenofibrate to improve lipid profiles and reach clinical guideline targets among hypertriglyceridemic patients.

Fenofibrate is a peroxisome proliferator-activated receptor alpha (PPARalpha) agonist which regulates the transcription of genes encoding proteins involved in triglyceride (TG)-rich lipoproteins and lipoprotein lipase (LPL) metabolism. The aim of the present study was to investigate the relation between TG-related parameters considered in different clinical guidelines used in industrialized countries for the management of lipid disorders (namely fasting plasma TG, high density-lipoprotein cholesterol (HDL-C), non-HDL-C concentrations and total-C/HDL-C ratio) and the presence of LPL-null (P207L), LPL-defective (D9N), PPARalpha -L162V, apolipoprotein (apo) E and PPARgamma-P12A gene mutations, in a sample of 292 hypertriglyceridemic subjects treated with fenofibrate for 3 months. Although fenofibrate induced a decrease in plasma TG level and an increase in HDL-C level in all studied genotypes, mutation-specific differences were observed. After adjustment for age, gender, body mass index and the presence of apo E2 genotype, the LPL-P207L mutation was associated with residual post-treatment hypertriglyceridemia [TG > 2.0 mmol/l, odds ratio (OR) = 3.07, P = 0.005] and total-C/HDL-C ratio > 5 (OR = 2.68; P = 0.03). This effect was significantly related to higher plasma TG concentrations at baseline among carriers of a LPL-null mutation. Compared to apo E3 and E4 variants, the apo E2 allele was associated with a better response to fenofibrate on all lipid parameter, especially among PPARalpha -L162V carriers, whereas the simultaneous presence of apo E2 and PPARalpha -L162V tended to improve fenofibrate response among LPL-P207L heterozygotes. Finally, the LPL-D9N and PPARgamma -P12A mutations did not affect fenofibrate lipid-lowering action. This study suggests that frequent genetic variations in genes encoding proteins involved in TG-rich lipoprotein metabolism could modulate the response to fenofibrate treatment, as defined in clinical guidelines.

Adult↗

Primary mediastinal and testicular seminomas: a comparison of K-ras-2 gene sequence and p53 immunoperoxidase analysis of 26 cases.

Primary mediastinal seminomas (MS) are rare tumors. Histologically, they are similar to their counterpart in the gonads. The survival rate has varied from 50% to 85% in different series. However, large series of these tumors primarily in the mediastinum are lacking. At the molecular level, a few reports document K-ras mutations in up to 40% of testicular seminomas (TS), localized predominantly to codon 12. Reports on TS p53 immunohistochemistry (IHC) range from negative to overexpression approaching 90% of cases, and by sequence analysis one small series showed a 23% mutation rate. To date, no analyses have been performed for either K-ras mutations or p53 immunohistochemical expression in primary MS. The authors studied 13 cases each of primary MS and TS from archival formalin-fixed, paraffin-embedded sections in which adequate tumor sampling and clinical history, including serological studies, and histological, histochemical, and IHC staining, were performed to confirm the diagnosis. p53 immunoperoxidase staining using citrate buffer/microwave antigen retrieval was performed. Topographic genotyping was performed on 5-microns-thick tissue sections up to 17 years old, in which the neoplastic cell population was sampled. Additionally, multiple sites within a given cases were sampled to determine clonality of the tumor cell population. Polymerase chain reaction and subsequent sequence analysis of the K-ras-2 exon-1 gene was used for mutation analysis. Focal weak staining with p53 IHC was observed in 4 of 13 (31%) MS and 10 of 13 (77%) TS cases, with all remaining cases being negative (P < .05). Only one MS case (8%) showed K-ras mutation (codon 13 GGC > GAC; glycine > aspartate), which is in contrast to 2 of the TS cases (15%), showing codon 12 mutations. All the remaining cases were wild type. Therefore, primary mediastinal seminomas appear to be different in their K-ras sequence and p53 immunostain profile from TS. Codon mutation type may be useful in determining primary versus metastatic origin of a mediastinal seminoma.

Adolescent↗

Several mutations in the melanocortin 4 receptor gene are associated with obesity in Chinese children and adolescents.

AIM: To screen mutations in the melanocortin 4 receptor (MC4R) in obese and normal-weight Chinese children and adolescents. METHODS: Three hundred Chinese children and adolescents, including 200 obese and 100 healthy non-obese individuals, were evaluated. The coding region of the MC4R gene was amplified by polymerase chain reaction (PCR) and sequenced. RESULTS: In obese individuals, we detected two novel heterozygous non-synonymous mutations (c.496G>A, resulting in Val166Ile; c.929G>A, resulting in Arg310Lys) and a novel heterozygous non-sense mutation (c.831T>A, resulting in a premature stop codon Cys277Stop). In both obese individuals and controls, a novel heterozygous non-synonymous mutation (c.68T>G, resulting in Leu23Arg, 0.5 and 1%, respectively) and the Val103Ile polymorphism (c.307G>A, 3 and 2%, respectively) were found. There was no difference in alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), cholesterol (CHOL) and whole body insulin sensitivity index (WBISI) between obese individuals with and without mutation. The prevalence for heterozygous MC4R mutations was 1.5% in the obese. CONCLUSIONS: Two novel heterozygous non-synonymous mutations (Val166Ile; Arg310Lys) and a novel heterozygous non-sense mutation (Cys277Stop) were detected in Chinese obese individuals. Leu23Arg variant might be a polymorphism in the Chinese population. There were no differences between clinical and biochemical profiles in the heterozygous mutations and the wild type.

Adolescent↗

Engineering steroid hormone specificity into aldo-keto reductases.

Steroid hormone transforming aldo-keto reductases (AKRs) include virtually all mammalian 3alpha-hydroxysteroid dehydrogenases (3alpha-HSDs), 20alpha-HSDs, as well as the 5beta-reductases. To elucidate the molecular determinants of steroid hormone recognition we used rat liver 3alpha-HSD (AKR1C9) as a starting structure to engineer either 5beta-reductase or 20alpha-HSD activity. 5beta-Reductase activity was introduced by a single point mutation in which the conserved catalytic His (H117) was mutated to Glu117. The H117E mutant had a k(cat) comparable to that for homogeneous rat and human liver 5beta-reductases. pH versus k(cat) profiles show that this mutation increases the acidity of the catalytic general acid Tyr55. It is proposed that the increased TyrOH(2)(+) character facilitates enolization of the Delta(4)-3-ketosteroid and subsequent hydride transfer to C5. Since 5beta-reductase precedes 3alpha-HSD in steroid hormone metabolism it is likely that this metabolic pathway arose by gene duplication and point mutation. 3alpha-HSD is positional and stereospecific for 3-ketosteroids and inactivates androgens. The enzyme was converted to a robust 20alpha-HSD, which is positional and stereospecific for 20-ketosteroids and inactivates progesterone, by the generation of loop-chimeras. The shift in log(10)(k(cat)/K(m)) from androgens to progestins was of the order of 10(11). This represents a rare example of how steroid hormone specificity can be changed at the enzyme level. Protein engineering with predicted outcomes demonstrates that the molecular determinants of steroid hormone recognition in AKRs will be ultimately rationalized.

20-Hydroxysteroid Dehydrogenases↗

MALDI-TOF based mutation detection using tagged in vitro synthesized peptides.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) is a powerful method to quickly and accurately determine the masses of peptides. Most genetic analyses, however, begin with PCR amplification of a test sequence to generate DNA, which is more difficult than peptides to analyze by MALDI-TOF. We describe a method that produces a PCR product of any continuous region of coding sequence which can then be used to encode an N-terminally tagged test peptide in a coupled in vitro transcription/translation reaction. The test peptide is purified using the tag, and its mass is measured by MALDI-TOF. Truncations and amino acid substitutions in peptides coded for by the breast cancer susceptibility gene BRCA1 were readily identified using this method. The process can be multiplexed and is amenable to automation, providing an efficient, high-throughput means for mutation discovery and genetic profiling.

Amino Acid Sequence↗

17alpha-hydroxylase/17,20-Lyase deficiency due to novel compound heterozygote mutations: treatment for tall stature in a female with male pseudohermaphroditism and spontaneous puberty in her affected sister.

We report on two German sisters with deficiency in the 17alpha-hydroxylase/17,20-lyase enzyme corresponding to typical hormone profile. A paternal nonsense mutation R388X in exon 7 and a maternal missense mutation P428L in exon 8 of the CYP17 gene have been identified in both girls. Residual in vitro 17alpha-hydroxylase activity for the conversion of [3H]-Preg to [3H]-17OH-Preg has been detected in transfected 293-cells expressing P428L mutant enzyme; however, no 17,20-lyase activity was observed converting [3H]-17OH-Preg into [3H]-DHEA. The 46,XX-sister spontaneously entered puberty. The 46,XY-sister with a predicted adult height of 203 cm was treated with a high dose of conjugated estrogens and resulted with a final height of 186.9 cm. The present data suggest that compound heterozygous 46,XX females bearing a P428L allele may develop spontaneous onset of puberty. Furthermore, in 46,XY females with tall stature, treatment with conjugated estrogens may lead to a significant reduction of their predicted adult height.

Adolescent↗

An unusual melting curve profile in LightCycler multiplex genotyping of the hemochromatosis H63D/C282Y gene mutations.

OBJECTIVES: Real time polymerase chain reaction followed by melting curve analysis using hybridization probes has become an important tool in routine diagnosis of the HFE mutations, which are associated with hereditary hemochromatosis. DESIGN AND METHODS: We used the LightCycler technology for simultaneous detection of the H63D and C282Y mutations of the HFE gene in patients with a higher prevalence for hemochromatosis. RESULTS: In our cohort we identified two siblings with a variant pattern of the HFE-LightCycler melting profiles preventing allelic discrimination. CONCLUSIONS: As a consequence, in these patients DNA sequencing or RFLP analysis is necessary to unequivocally assign the correct HFE genotype.

Amino Acid Substitution↗

BRCA1 genetic testing in 106 breast and ovarian cancer families from Southern Italy (Sicily): a mutation analyses.

PURPOSE: To evaluate the contribution of germline BRCA1 mutations in the incidence of hereditary and familial Breast Cancer (BC) and/or Ovarian Cancer (OC) in patients from Southern Italy (in the region of Sicily) and to identify a possible association between the higher frequency of BRCA1 mutations and a specific familial profile. EXPERIMENTAL DESIGN: A consecutive series of 650 patients with BC and/or OC diagnosed between 1999 and 2005 were recruited from the Southern Italian region of Sicily, after interview at the "Regional Reference Centre for the Characterization and Genetic Screening of Hereditary Tumors" at the University of Palermo. Genetic counselling allowed us to recruit a total of 106 unrelated families affected with breast and/or ovarian cancer screened for mutations occurring in the whole BRCA1 gene by automatic direct sequencing. RESULTS: Germline BRCA1 mutations were found in 17 of 106 (16%) Sicilian families. The HBOC profile had a major frequency (66%) of mutations (P < 0.01). A total of 28 sequence variants was identified. Seven of these were pathogenic, 5 unknown biological variant (UV) and 16 polymorphisms. We also identified a pathological mutation (4843delC) as a possible Sicilian founder mutation. CONCLUSIONS: The present study is the first BRCA1 disease-associated mutations analysis in Southern Italian families. The early age of onset of such tumors and the association with the HBOC familial profile could be two valid screening factors for the identification of BRCA1 mutation carriers. Finally, we identified a BRCA1 mutation with a possible founder effect.

Adult↗