Molecular Testing Guideline Research Articles

Clinical Validation of a Novel Commercial Reverse Transcription–Quantitative Polymerase Chain Reaction Screening Assay for Detection of ALK Translocations and Amplifications in Non–Small Cell Lung Carcinomas

-EGFR mutations and anaplastic lymphoma kinase (ALK) translocations have significant biologic and therapeutic implications in lung cancers, particularly lung adenocarcinomas. ALK translocations are less frequent compared with EGFR mutations; interestingly, these two abnormalities are most commonly mutually exclusive. The 2013 College of American Pathologists/Association for Molecular Pathology/International Association for the Study of Lung Cancer molecular testing guideline for lung cancers recommend a testing algorithm in which detection of ALK translocations using fluorescence in situ hybridization (FISH) is to be performed following testing for EGFR mutations. Such an algorithm is cost-effective but potentially slows down turnaround time; and as a secondary test, ALK FISH assay may not be completed because it requires the use of additional tissue, and the small biopsies or cytology specimens may have been exhausted in the extraction of nucleic acid for EGFR mutation screening. -To provide efficient testing of both EGFR and ALK genetic alterations in small biopsies and cytology specimens. -We validated a highly sensitive ALK reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay as a screening tool for ALK translocations and amplifications. -We performed a retrospective review of cases previously tested by FISH and found that all FISH ALK translocation-positive specimens were RT-qPCR positive, and all FISH ALK translocation-negative cases were RT-qPCR negative (the sensitivity and specificity of the ALK RT-qPCR assay were 100%). -This assay allows rapid identification of ALK alterations, can be performed in conjunction with EGFR testing, and does not require use of valuable additional tumor tissue.

Verification of Inter-laboratorial Genotyping Consistency in the Molecular Diagnosis of Polyglutamine Spinocerebellar Ataxias

The polyglutamine spinocerebellar ataxias (SCAs) constitute a clinically and genetically heterogeneous group of rare late-onset neurodegenerative disorders, caused by CAG expansions in the coding region of the respective genes. Given their considerable clinical overlapping, differential diagnosis relies on molecular testing. Laboratory best practice guidelines for molecular genetic testing of the SCAs were released in 2010 by the European Molecular Genetics Quality Network, following the recognition of gross genotyping errors by some diagnostic laboratories. The main goal of this study was to verify the existence of inter-laboratorial consistency comparing genotypes for SCA1, SCA2, SCA3, SCA6 and SCA7 obtained by independent diagnostic laboratories. The individual impact of different methodological issues on the genotype for the several SCAs was also analysed. Four international collaborative diagnostic laboratories provided 79 samples and the respective SCA genotypes. Samples were genotyped in-house for all SCAs using an independent methodology; comparison of the allele size obtained with the one provided by the collaborative laboratories was performed. Globally, no significant differences were identified, a result which could be reflecting the fulfilment of recommendations for the molecular testing of SCAs and demonstrating an improvement in genotyping accuracy.

Somatic STK11 and concomitant STK11/KRAS mutational frequency in stage IV lung adenocarcinoma adrenal metastases.

Somatic serine/threonine kinase 11 (STK11) also known as liver kinase B1 (LKB1) is a tumor suppressor gene and ranks as the third most frequently mutated gene in lung adenocarcinoma. However, current molecular testing guidelines recommend evaluating for epidermal growth factor receptor mutations and ALK fusions to guide therapy in all patients with advanced stage adenocarcinoma, regardless of gender, race, or smoking history. Identifying alternative "driver" mutations and using actionable targeted pharmacotherapy is a key approach to providing effective individualized medical care. The analytical sensitivity and parallel multigene approach of targeted next-generation sequencing is an attractive methodology for use for cytology specimens. The presented lung adenocarcinoma study revealed that STK11 mutations alone and concomitant KRAS/STK11 mutations were identified in 18.2% and 4.5% of solitary adrenal metastases, respectively. Molecular profiling of epidermal growth factor receptor tyrosine kinase inhibitor resistant tumors may help to identify patients who would most benefit from alternative single or dual pathway inhibition potentially leading to a revision in current molecular testing guidelines.

Molecular alterations in non‐small‐cell lung cancer: Perspective for targeted therapy and specimen management for the bronchoscopist

Major advances have occurred over the past decade in our understanding of lung cancer pathobiology. Increasing knowledge of molecular aberrations in lung cancer, specifically the discovery of two driver genes in pharmacologically targetable tyrosine kinases involved in growth factor receptor signalling, epidermal growth factor receptor and anaplastic lymphoma kinase, has been of major therapeutic and prognostic importance. This discovery has allowed for new, personalized approach to the management of lung cancer. Recognizing the importance of molecular signatures of lung cancer, the College of American Pathologists, International Association for the Study of Lung Cancer and Association for Molecular Pathology released the first guidelines for molecular testing in lung cancer. The introduction of minimally invasive needle techniques for the evaluation of lung cancer patients, such as endobronchial ultrasound transbronchial needle aspiration and oesophageal ultrasound-fine-needle aspiration, has revolutionized the way lung cancer patients are assessed. Samples obtained using the minimally invasive needle approaches have been shown to be sufficient not only for routine molecular testing but also for multigenic analysis. This allows bronchoscopist to assume an increasingly important role in the diagnostic workup of patients with lung cancer at all stages of the disease and contribute to personalizing the care of lung cancer patients.

Thyroid Surgical Care 2014: Ultrasound, Fine‐Needle Aspiration, Molecular Testing, and the American Thyroid Association Guidelines

Program Description: Evaluation of thyroid nodules with surgeon-performed ultrasound and fine-needle aspiration (FNA), armed with molecular testing, is rapidly transforming thyroid surgery. Didactic presentations and case studies including American Thyroid Association (ATA) guidelines will provide participants with risk stratification using ultrasound and pearls for surgeon-performed FNA. Molecular Classifiers have a 95% negative predictive value for indeterminate nodules reducing unnecessary diagnostic lobectomies. Molecular alteration testing from FNA with panels including BRAF is 100% specific for papillary thyroid cancer and has evolved into next-generation sequencing from the cancer genome atlas (TCGA). Combined mutation marker analysis has improved prognostic information. Personalized thyroid cancer surgical management is approaching. Educational Objectives: (1) Explain that Molecular Classifier testing for cytologically indeterminate nodules may reduce the number of unnecessary diagnostic thyroid lobectomies. (2) Recognize next-generation sequencing and the cancer genome atlas for cytologically indeterminate nodules will improve the diagnosis of thyroid cancer. (3) Interpret ATA guidelines for ultrasound, FNA, molecular testing, and prognostication.

Molecular testing guidelines for lung adenocarcinoma: Utility of cell blocks and concordance between fine-needle aspiration cytology and histology samples.

Background:Lung cancer is a leading cause of mortality, and patients often present at a late stage. More recently, advances in screening, diagnosing, and treating lung cancer have been made. For instance, greater numbers of minimally invasive procedures are being performed, and identification of lung adenocarcinoma driver mutations has led to the implementation of targeted therapies. Advances in molecular techniques enable use of scant tissue, including cytology specimens. In addition, per recently published consensus guidelines, cytology-derived cell blocks (CBs) are preferred over direct smears. Yet, limited comparison of molecular testing of fine-needle aspiration (FNA) CBs and corresponding histology specimens has been performed. This study aimed to establish concordance of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma (KRAS) virus homolog testing between FNA CBs and histology samples from the same patients.Materials and Methods:Patients for whom molecular testing for EGFR or KRAS was performed on both FNA CBs and histology samples containing lung adenocarcinoma were identified retrospectively. Following microdissection, when necessary, concordance of EGFR and KRAS molecular testing results between FNA CBs and histology samples was evaluated.Results:EGFR and/or KRAS testing was performed on samples obtained from 26 patients. Concordant results were obtained for all EGFR (22/22) and KRAS (17/17) mutation analyses performed.Conclusions:Identification of mutations in lung adenocarcinomas affects clinical decision-making, and it is important that results from small samples be accurate. This study demonstrates that molecular testing on cytology CBs is as sensitive and specific as that on histology.

Molecular testing in lung cancer: fine-needle aspiration specimen adequacy and test prioritization prior to the CAP/IASLC/AMP Molecular Testing Guideline publication.

Subtyping of lung carcinoma with immunohistochemistry is essential for diagnosis, whereas molecular testing (MT) is required for therapy guidance. In the current study, the authors report on MT performed on fine-needle aspiration specimens at the study institution over a 2-year period preceding the April 2013 College of American Pathologists (CAP)/International Association for the Study of Lung Cancer (IASLC)/Association for Molecular Pathology (AMP) Molecular Testing Guideline (MTG) publication. The database of the study institution was retrospectively queried for cases of lung and thoracic/lower cervical lymph node fine-needle aspiration specimens for 2011 through 2012. Of 246 selected cases, 26 featured a limited amount of material in cell blocks. MT increased significantly between 2011 and 2012 and was requested in 39.4% of cases (97 of 246 cases): 86 of those cases had at least 1 MT result and 11 had insufficient material for any MT. Anaplastic lymphoma kinase (ALK) testing was performed in 9 cases in which DNA was insufficient for epidermal growth factor receptor (EGFR) testing. In addition, 13 cases of adenocarcinoma/non-small cell lung carcinoma had at least 1 MT canceled because of insufficient DNA, but at the same time had an average of 3.46 immunohistochemical stains performed. Of all the cytology specimens, 10.6% featured limited material; however, no universally accepted testing sequence priority was available at the time the study was performed. As per the MTG, MT should take precedence over immunohistochemistry in cases of adenocarcinoma/non-small cell lung carcinoma. Approximately 5.3% of the specimens in the current study had insufficient material for MT while having multiple stains performed instead. The MTG also recommend performing EGFR before ALK testing; the authors found 9 cases with insufficient material for EGFR testing that had ALK testing performed. The results of the current study underscore the need for a testing prioritization algorithm in view of the MTG publication to serve as reference for both clinicians and pathologists.

Present and Future Molecular Testing of Lung Carcinoma

The rapid development of targeted therapies has tremendously changed clinical management of lung carcinoma patients and set the stage for similar developments in other tumor types. Many studies have been published in the past decade in search for the most acceptable method of assessment for predictors of response to targeted therapies in lung cancer. As a result, several guidelines for molecular testing have been published in a past couple of years. Because of accumulated evidence that targetable drugs show the best efficacy and improved progression survival rates in lung cancer patients whose tumors have a specific genotype, molecular testing for predictors of therapy response has became standard of care. Presently, testing for EGFR mutations and ALK rearrangements in lung adenocarcinoma has been standardized. The landscape of targetable genomic alterations in lung carcinoma is expanding, but none of other potentially targetable biomarkers have been standardized outside of clinical trials. This review will summarize current practice of molecular testing. Future methods in molecular testing of lung carcinoma will be briefly reviewed.

Molecular testing guidelines for selection of colorectal cancer patients for targeted and conventional therapies.

600 Background: Molecular testing to enhance the response of colorectal cancers (CRC) to targeted and conventional therapies has been the center of many recent studies. While testing for KRAS mutations is generally accepted as a requirement to select patients for anti-EGFR antibody therapies, evidence-based guidelines for other markers are needed. The objective of this project is to establish evidence-based recommendations for the molecular testing of CRC tissues to guide EGFR-targeted therapies and conventional chemotherapy regimens. Methods: Three professional societies: American Society of Clinical Pathologists (ASCP), College of American Pathologists (CAP) and the Association for Molecular Pathology (AMP) have selected co-chairs, and multidisciplinary expert and advisory panels, which include specialists in pathology, GI oncology, surgery, gastroenterology and genetics. A systematic review was designed based on five overall key questions: (1) What biomarkers are useful for CRC management (selection of patients for targeted and conventional therapies)? (2) How should tissue specimens be processed for biomarker testing for CRC management?; (3) How should biomarker testing for CRC management be performed? (4) How should molecular testing of CRC be implemented and operationalized?; V: Should other genes/biomarkers be routinely tested? The expert panel will review title-abstract (TA) and full-text (FT) in DistillerSR software. Data extraction will then be performed and the panel will draft recommendations based upon evidence tables and the considered judgment process. Results: A systematic review was performed to capture published articles from January 2009 through August 2013, yielding 2,883titles to date. Currently the TA review phase is in course. Release of draft recommendations during an open comment period is anticipated in early 2014. Conclusions: The ASCP-CAP-AMP Molecular Testing Guidelines for Selection of Colorectal Cancer Patients for Targeted and Conventional Therapies will provide evidence-based guidelines for molecular testing of CRC. The final publication release is anticipated for the fall 2014.

Genes and Pathology of Non-Small Cell Lung Carcinoma

While histopathology has traditionally been the cornerstone of treatment decisions in the management of lung cancer patients, the complexity and heterogeneity of histological classification has had a limited impact in the routine practice of oncology. This has changed dramatically in the last few years, owing to discoveries of genomic aberrations and results of clinical trials of novel and targeted therapies. These discoveries have resulted in a new way of classifying non-small cell lung cancer (NSCLC), based on the occurrence of putative or proven driver and targetable genomic changes. The rapidity by which the landscape of mutation and genomic changes is being identified also has led to a new paradigm and approaches to pathological diagnosis of NSCLC. In this context, international consortia have proposed new classifications of lung adenocarcinoma and guidelines for molecular testing in lung cancer and have provided concrete recommendations on new ways to practice lung cancer pathology.

Molecular Testing in Lung Cancer - Specimen Adequacy and Test Prioritization in View of CAP/IASLC/AMP Molecular Testing Guideline Publication

Molecular Testing in Lung Cancer - Specimen Adequacy and Test Prioritization in View of CAP/IASLC/AMP Molecular Testing Guideline Publication

Lung Cancer Biomarkers: Present Status and Future Developments

The publication of the "Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology" has now provided a guideline for biomarker testing for first-generation lung cancer tyrosine kinase inhibitors. Biomarker testing has forever altered the role of pathologists in the management of patients with lung cancer. Current, unresolved issues in the precision medicine of lung cancer will be addressed by the development of new biomarker tests, new drugs, and new test technologies and by improvement in the cost to benefit ratio of biomarker testing.

Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors: Guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

To establish evidence-based recommendations for the molecular analysis of lung cancers that are that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed. Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies. Three unbiased literature searches of electronic databases were performed to capture articles published published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation. Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4). The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Impact of the new EGF receptor and ALK testing guideline on personalized lung cancer medicine.

All advanced-stage lung adenocarcinoma patients should be tested for EGF receptor (EGFR) mutations and for EML4–ALK translocations as a guide for selecting them for tyrosine kinase inhibitor (TKI) therapy. The new EGFR and ALK guideline provides useful recommendations for appropriate testing [1]. Lung tumors are the leading cause of cancerrelated mortality worldwide [2]. Almost 80% of cases are non-small-cell lung cancer (NSCLC) and extensive disease is present at the time of diagnosis in the majority of patients. Systemic treatment with chemotherapy has reached a plateau of 10–20% response rates and 4–5 months of progression-free survival (PFS), and has not improved in more than a decade [3–5]. A first milestone in a new era of targeted therapy for this disease was reached with the discovery of a subset of tumors carrying activating mutations of EGFR, which can be selectively blocked with TKIs such as erlotinib and gefitinib. Numerous clinical studies have demonstrated the efficacy of these TKIs in the treatment of EGFR-mutated lung tumors, with 55–83% response rates and 9–13 month PFS [6,7]. A second milestone was the discovery, in 2007, of the EML4–ALK translocation in 6.7% of Japanese NSCLC patients [8]. The translocation was later found in 4–7% of Chinese [9], European [10] and US patients [11]. When treated with a novel ALK inhibitor, crizotinib, these patients showed response rates of 57% with a PFS greater than 6 months [12]. As a result of these new developments, many laboratories worldwide are currently testing lung tumor samples for EGFR mutations and EML4–ALK fusions. In an effort to standardize testing practices, the College of American Pathologists, the International Association for the Study of Lung Cancer and the Association for Molecular Pathology constituted writing and advisory panels, presided by three cochairs, to

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology.

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed. Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies. Three unbiased literature searches of electronic databases were performed to capture articles published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation. Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4). The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

The CAP-IASLC-AMP molecular testing guideline for the selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors.

11085 Background: The College of American Pathologists (CAP), the International Association for the Study of Lung Cancer (IASLC), and the Association for Molecular Pathology (AMP) jointly initiated an effort to establish evidence-based recommendations for the molecular analysis of lung cancers required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed. Methods: Three co-chairs without relevant conflicts of interest were selected, one from each of the sponsoring societies: CAP (P.T.C.), IASLC (M.L.), and AMP (N.I.L.). Writing and advisory panels were formed from additional experts from these societies. Unbiased literature searches were performed to capture articles up to February 2012, yielding 1,533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for relevance. Evidence was formally graded for each of the recommendations first formulated by the co-chairs and panel members at a public meeting. Each guideline section was assigned to at least two panelists. Successive drafts were circulated for comments to the writing panel, the advisory panel, the public (online posting), and the three professional societies. Results: We generated 37 guideline items addressing 14 areas of EGFR and ALK testing. The major, evidence-based recommendations are to test for EGFR mutations and ALK fusions in all patients with advanced stage adenocarcinoma, regardless of sex, race, or smoking history, and to prioritize EGFR and ALK testing over other molecular predictive tests. Recommendations and expert consensus opinions were generated for all other key aspects of EGFR and ALK testing in lung cancer related to oncology and pathology practice and technical issues in molecular testing. Conclusions: As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards and thereby improving patient outcomes.

Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors: Guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed. Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies. Three unbiased literature searches of electronic databases were performed to capture published articles from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. EVIDENCE was formally graded for each recommendation. Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4). The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

A Streamlined Protocol for Molecular Testing of the DMD Gene within a Diagnostic Laboratory: A Combination of Array Comparative Genomic Hybridization and Bidirectional Sequence Analysis

Purpose. The aim of this study was to develop a streamlined mutation screening protocol for the DMD gene in order to confirm a clinical diagnosis of Duchenne or Becker muscular dystrophy in affected males and to clarify the carrier status of female family members. Methods. Sequence analysis and array comparative genomic hybridization (aCGH) were used to identify mutations in the dystrophin DMD gene. We analysed genomic DNA from six individuals with a range of previously characterised mutations and from eight individuals who had not previously undergone any form of molecular analysis. Results. We successfully identified the known mutations in all six patients. A molecular diagnosis was also made in three of the four patients with a clinical diagnosis who had not undergone prior genetic screening, and testing for familial mutations was successfully completed for the remaining four patients. Conclusion. The mutation screening protocol described here meets best practice guidelines for molecular testing of the DMD gene in a diagnostic laboratory. The aCGH method is a superior alternative to more conventional assays such as multiplex ligation-dependent probe amplification (MLPA). The combination of aCGH and sequence analysis will detect mutations in 98% of patients with the Duchenne or Becker muscular dystrophy.

EMQN best practice guidelines for the laboratory diagnosis of osteogenesis imperfecta

Osteogenesis imperfecta (OI) comprises a group of inherited disorders characterized by bone fragility and increased susceptibility to fractures. Historically, the laboratory confirmation of the diagnosis OI rested on cultured dermal fibroblasts to identify decreased or abnormal production of abnormal type I (pro)collagen molecules, measured by gel electrophoresis. With the discovery of COL1A1 and COL1A2 gene variants as a cause of OI, sequence analysis of these genes was added to the diagnostic process. Nowadays, OI is known to be genetically heterogeneous. About 90% of individuals with OI are heterozygous for causative variants in the COL1A1 and COL1A2 genes. The majority of remaining affected individuals have recessively inherited forms of OI with the causative variants in the more recently discovered genes CRTAP, FKBP10, LEPRE1,PLOD2, PPIB, SERPINF1, SERPINH1 and SP7, or in other yet undiscovered genes. These advances in the molecular genetic diagnosis of OI prompted us to develop new guidelines for molecular testing and reporting of results in which we take into account that testing is also used to ‘exclude' OI when there is suspicion of non-accidental injury. Diagnostic flow, methods and reporting scenarios were discussed during an international workshop with 17 clinicians and scientists from 11 countries and converged in these best practice guidelines for the laboratory diagnosis of OI.

Erratum: Corrigendum to: EMQN Best Practice Guidelines for molecular genetic testing of SCAs

Correction to: European Journal of Human Genetics advance online publication, 24 February 2010; doi:10.1038/ejhg.2010.8 Since the publication of the above paper the authors realized that the other co-authors who took part to the EMQN Best Practice Meeting and electronic discussion were not indexed as such.