Dominantly inherited micro-satellite instable cancer - the four Lynch syndromes - an EHTG, PLSD position statement.

The recognition of dominantly inherited micro-satellite instable (MSI) cancers caused by pathogenic variants in one of the four mismatch repair (MMR) genes MSH2, MLH1, MSH6 and PMS2 has modified our understanding of carcinogenesis. Inherited loss of function variants in each of these MMR genes cause four dominantly inherited cancer syndromes with different penetrance and expressivities: the four Lynch syndromes. No person has an "average sex "or a pathogenic variant in an "average Lynch syndrome gene" and results that are not stratified by gene and sex will be valid for no one. Carcinogenesis may be a linear process from increased cellular division to localized cancer to metastasis. In addition, in the Lynch syndromes (LS) we now recognize a dynamic balance between two stochastic processes: MSI producing abnormal cells, and the host's adaptive immune system's ability to remove them. The latter may explain why colonoscopy surveillance does not reduce the incidence of colorectal cancer in LS, while it may improve the prognosis. Most early onset colon, endometrial and ovarian cancers in LS are now cured and most cancer related deaths are after subsequent cancers in other organs. Aspirin reduces the incidence of colorectal and other cancers in LS. Immunotherapy increases the host immune system's capability to destroy MSI cancers. Colonoscopy surveillance, aspirin prevention and immunotherapy represent major steps forward in personalized precision medicine to prevent and cure inherited MSI cancer.

Achondroplasia in Latin America: practical recommendations for the multidisciplinary care of pediatric patients.

BACKGROUND: Achondroplasia is the most common bone dysplasia associated with disproportionate short stature, and other comorbidities, such as foramen magnum stenosis, thoracolumbar kyphosis, lumbar hyperlordosis, genu varum and spinal compression. Additionally, patients affected with this condition have higher frequency of sleep disorders, ear infections, hearing loss and slowed development milestones. Considering these clinical features, we aimed to summarize the regional experts' recommendations for the multidisciplinary management of patients with achondroplasia in Latin America, a vast geographic territory with multicultural characteristics and with socio-economical differences of developing countries. METHODS: Latin American experts (from Argentina, Brazil, Chile and Colombia) particiáted of an Advisory Board meeting (October 2019), and had a structured discussion how patients with achondroplasia are followed in their healthcare centers and punctuated gaps and opportunities for regional improvement in the management of achondroplasia. RESULTS: Practical recommendations have been established for genetic counselling, prenatal diagnosis and planning of delivery in patients with achondroplasia. An outline of strategies was added as follow-up guidelines to specialists according to patient developmental phases, amongst them neurologic, orthopedic, otorhinolaryngologic, nutritional and anthropometric aspects, and related to development milestones. Additionally, the role of physical therapy, physical activity, phonoaudiology and other care related to the quality of life of patients and their families were discussed. Preoperative recommendations to patients with achondroplasia were also included. CONCLUSIONS: This study summarized the main expert recommendations for the health care professionals management of achondroplasia in Latin America, reinforcing that achondroplasia-associated comorbidities are not limited to orthopedic concerns.

Colorectal cancer incidences in Lynch syndrome: a comparison of results from the prospective lynch syndrome database and the international mismatch repair consortium.

OBJECTIVE: To compare colorectal cancer (CRC) incidences in carriers of pathogenic variants of the MMR genes in the PLSD and IMRC cohorts, of which only the former included mandatory colonoscopy surveillance for all participants. METHODS: CRC incidences were calculated in an intervention group comprising a cohort of confirmed carriers of pathogenic or likely pathogenic variants in mismatch repair genes (path_MMR) followed prospectively by the Prospective Lynch Syndrome Database (PLSD). All had colonoscopy surveillance, with polypectomy when polyps were identified. Comparison was made with a retrospective cohort reported by the International Mismatch Repair Consortium (IMRC). This comprised confirmed and inferred path_MMR carriers who were first- or second-degree relatives of Lynch syndrome probands. RESULTS: In the PLSD, 8,153 subjects had follow-up colonoscopy surveillance for a total of 67,604 years and 578 carriers had CRC diagnosed. Average cumulative incidences of CRC in path_MLH1 carriers at 70 years of age were 52% in males and 41% in females; for path_MSH2 50% and 39%; for path_MSH6 13% and 17% and for path_PMS2 11% and 8%. In contrast, in the IMRC cohort, corresponding cumulative incidences were 40% and 27%; 34% and 23%; 16% and 8% and 7% and 6%. Comparing just the European carriers in the two series gave similar findings. Numbers in the PLSD series did not allow comparisons of carriers from other continents separately. Cumulative incidences at 25 years were < 1% in all retrospective groups. CONCLUSIONS: Prospectively observed CRC incidences (PLSD) in path_MLH1 and path_MSH2 carriers undergoing colonoscopy surveillance and polypectomy were higher than in the retrospective (IMRC) series, and were not reduced in path_MSH6 carriers. These findings were the opposite to those expected. CRC point incidence before 50 years of age was reduced in path_PMS2 carriers subjected to colonoscopy, but not significantly so.

A survey of the clinicopathological and molecular characteristics of patients with suspected Lynch syndrome in Latin America.

BACKGROUND: Genetic counselling and testing for Lynch syndrome (LS) have recently been introduced in several Latin America countries. We aimed to characterize the clinical, molecular and mismatch repair (MMR) variants spectrum of patients with suspected LS in Latin America. METHODS: Eleven LS hereditary cancer registries and 34 published LS databases were used to identify unrelated families that fulfilled the Amsterdam II (AMSII) criteria and/or the Bethesda guidelines or suggestive of a dominant colorectal (CRC) inheritance syndrome. RESULTS: We performed a thorough investigation of 15 countries and identified 6 countries where germline genetic testing for LS is available and 3 countries where tumor testing is used in the LS diagnosis. The spectrum of pathogenic MMR variants included MLH1 up to 54%, MSH2 up to 43%, MSH6 up to 10%, PMS2 up to 3% and EPCAM up to 0.8%. The Latin America MMR spectrum is broad with a total of 220 different variants which 80% were private and 20% were recurrent. Frequent regions included exons 11 of MLH1 (15%), exon 3 and 7 of MSH2 (17 and 15%, respectively), exon 4 of MSH6 (65%), exons 11 and 13 of PMS2 (31% and 23%, respectively). Sixteen international founder variants in MLH1, MSH2 and MSH6 were identified and 41 (19%) variants have not previously been reported, thus representing novel genetic variants in the MMR genes. The AMSII criteria was the most used clinical criteria to identify pathogenic MMR carriers although microsatellite instability, immunohistochemistry and family history are still the primary methods in several countries where no genetic testing for LS is available yet. CONCLUSION: The Latin America LS pathogenic MMR variants spectrum included new variants, frequently altered genetic regions and potential founder effects, emphasizing the relevance implementing Lynch syndrome genetic testing and counseling in all of Latin America countries.

Clinical characteristics of patients with Breast and / or Ovarian Cancer with mutations in the BRCA1 and BRCA2 genes in Córdoba, Argentina / [Características clínicas de pacientes con Cáncer de Mama y / o Cáncer de Ovario con mutaciones en los genes BRCA1 y BRCA2 en Córdoba, Argentina.]

Introduction: Hereditary predisposition syndromes to cancer represent 5-10% of cancer cases, the most studied being HBOC produced by mutations in the BRCA1/2 genes. Objectives: To describe clinical, histopathological and PV characteristics in patients with HBOC in Córdoba, Argentina and compare it with those without BRCA1/2 mutations. Methods: Cross-sectional, correlational and observational analysis of patients from Córdoba. The ANOVA, Student's t test contingency tables and Fisher exact test were used the significance level was α = 0.05. Results: 155 women with BC, OC and BC/OC were studied. 40 BRCA1 / 2 mutations were identified. No differences were found in the age of diagnosis between patients with and without BRCA1/2 mutations. A significant association was found between VP in BRCA1/2 and the type of cancer (p = 0.003); all cases with BC/OC presented mutations in BRCA1/2. No significant association was found between mutated/non-mutated and personal history, family background, and ER-PR-HER2. 23.1% and 38.1% of BC cases were TN in individuals with VP in BRCA 1 and 2, respectively. The prevalence of mutations was 25.8% and the prevalence of novel PV was 10.0%. Conclusions: Patients with BC-VP BRCA1/2 are associated with ductal histology, and younger age of presentation with VP BRCA1. We did not find significant differences in the age at diagnosis of BC between patients with BRCA1 and BRCA2 mutations, a higher proportion of BC TN is observed than in the general population. In our sample, the prevalence of BRCA1/2 mutations among patients who meet criteria for HBOC is 25.8%, with 10% new pathogenic variant.

Introducción: Los síndromes de predisposición hereditaria al cáncer representan un 5-10% de los casos de cáncer, el más estudiado es HBOC producido por mutaciones en los genes BRCA1/2. Objetivos: Describir características clínicas, histopatológicas y VP en pacientes con HBOC en Córdoba, Argentina y compararla con aquellas sin mutaciones en BRCA1/2. Métodos: Análisis transversal, correlacional y observacional de pacientes de Córdoba. Se utilizó la prueba ANOVA, t de Student, tablas de contingencia y prueba exacta de Fisher, el nivel de significancia fue α=0,05. Resultados: Se estudiaron 155 mujeres con CM, CO y CM/CO. Se identificaron 40 mutaciones en BRCA1/2. No se encontraron diferencias en edad de diagnóstico entre pacientes con y sin mutaciones en BRCA1/2. Se encontró asociación significativa entre VP en BRCA1/2 y el tipo de cáncer (p=0,003); todos los casos con CM/CO presentaron mutaciones en BRCA1/2. No se encontró asociación significativa entre mutados/no mutados y AP, AF, RE-RP-HER2. El 23.1% y 38.1% de los casos de CM fueron TN en individuos con VP en BRCA 1 y 2 respectivamente. La prevalencia de mutaciones fue 25,8% y la prevalencia de VP noveles del 10,0%. Conclusiones: Las pacientes con CM-VP BRCA1/2 están asociadas con histología ductal, y menor edad de presentación con VP BRCA1. No encontramos diferencias significativas en edad de diagnóstico del CM entre pacientes con mutaciones BRCA1 y BRCA2, se observa una mayor proporción CM TN que en la población en general. En nuestra muestra, la prevalencia de mutaciones en BRCA1/2 entre los pacientes que reúnen criterios para HBOC es del 25,8%, con 10% de VP noveles.

A snapshot of current genetic testing practice in Lynch syndrome: The results of a representative survey of 33 Latin American existing centres/registries.

We aimed to assess the current genetics practice to manage patients with Lynch syndrome (LS) across Latin America. A Latin American LS survey was sent out to 52 centres/registries, comprising a total of 12 countries from the region. Overall, 33 centres completed the survey, of which the oldest LS registry was established in 1992 in Sao Paulo (Brazil), and the youngest this year in San Jose (Costa Rica). In total, 87% (26/30) of the participating centres/registries belonging to the nine countries are performing genetic testing. Overall, 1352 suspected families were sequenced. Pathogenic variants were identified in 34% of the families, with slightly differing distribution of variants between females and males. Path_MLH1 variants were identified in 39% of females and 50% of males (p = 0.023), while path_MSH2 were identified in 37% of females and males, followed by path_PMS2 in 11% of females and 8% of males, path_MSH6 in 13% of females and 3% of males (p < 0.001) and path_EPCAM in 0.3% of females and 2% of males. In Latin America, 9 of 12 (75%) participating countries had implemented healthcare for LS. LS screening is inconsistently applied within Latin America healthcare systems because of structural differences in the healthcare systems between the countries.

Clinical findings in 32 patients with 22qll.2 microdeletion attended in the city of Córdoba, Argentina.

The 22q11.2 microdeletion is the most common deletion syndrome, with a prevalence of 1/4000-1/6000 among newborn infants and a wide phenotypic variability. The diagnosis of the 22q11.2 microdeletion is made through cytogenetics or fuorescence in situ hybridization (FISH). The objectives of this article were to describe the clinical features of 32 patients with 22q11.2 microdeletion and the fndings of other chromosomal abnormalities and genetic syndromes in phenotypically similar patients. This series was made up of 268 patients with clinical criteria supporting the diagnostic suspicion attended at the Hospital de Niños and Hospital Privado, of Córdoba, between March 1st, 2004 and August 31st, 2011. The following parameters were analyzed: age at the time of the diagnosis, sex, clinical manifestations, and mortality. Thirty-two patients (19 males and 13 females) had a positive result for this deletion. The diagnosis was made mostly in their frst months and years of life (age range: 7 days old-31 years old). The clinical manifestations were: congenital heart diseases (22/32), thymic hypoplasia-agenesis/ recurrent infections (10/32), velopalatal insuffciency (8/32). Five patients died; four due to a complication associated with their cardiovascular disease and one due to multiple organ failure. The clinical manifestations of the syndrome were varied.

Clinical fndings in 32 patients with 22qll.2 microdeletion attended in the city of Córdoba, Argentina / Hallazgos clínicos en 32 pacientes con microdeleción 22q11.2 asistidos en la ciudad de Córdoba, Argentina

The 22q11.2 microdeletion is the most common deletion syndrome, with a prevalence of 1/4000-1/6000 among newborn infants and a wide phenotypic variability. The diagnosis of the 22q11.2 microdeletion is made through cytogenetics or fuorescence in situ hybridization (FISH). The objectives of this article were to describe the clinical features of 32 patients with 22q11.2 microdeletion and the fndings of other chromosomal abnormalities and genetic syndromes in phenotypically similar patients. This series was made up of 268 patients with clinical criteria supporting the diagnostic suspicion attended at the Hospital de Niños and Hospital Privado, of Córdoba, between March 1st, 2004 and August 31st, 2011. The following parameters were analyzed: age at the time of the diagnosis, sex, clinical manifestations, and mortality. Thirty-two patients (19 males and 13 females) had a positive result for this deletion. The diagnosis was made mostly in their frst months and years of life (age range: 7 days old-31 years old). The clinical manifestations were: congenital heart diseases (22/32), thymic hypoplasia-agenesis/ recurrent infections (10/32), velopalatal insuffciency (8/32). Five patients died; four due to a complication associated with their cardiovascular disease and one due to multiple organ failure. The clinical manifestations of the syndrome were varied.

La microdeleción 22q11.2 es la más frecuente, afecta a 1/4000 a 1/6000 recién nacidos y tiene amplia variabilidad fenotípica. El diagnóstico se realiza por citogenética o hibridación in situ fuorescente (FISH). Los objetivos del presente trabajo fueron describir las características clínicas de 32 pacientes con microdeleción 22q11.2, y los hallazgos de otras anomalías cromosómicas y síndromes genéticos en pacientes fenotípicamente similares. La serie estuvo compuesta por 268 pacientes que tenían criterios clínicos de sospecha diagnóstica asistidos en los hospitales de Niños y Privado de Córdoba, desde el 1 de marzo de 2004 hasta el 31 de agosto de 2011. Se analizaron: edad en el momento del diagnóstico, sexo, manifestaciones clínicas y mortalidad. Resultaron positivos para esta deleción, 32 pacientes (19 varones y 13 mujeres). El diagnóstico se realizó mayoritariamente en los primeros meses y años de vida (rango etario: 7 días a 31 años). Clínica: cardiopatías congénitas (22/32), hipoplasia-agenesia-tímica/ infecciones recurrentes (10/32); hipotonía velopalatina (8/32). Cinco murieron, cuatro por complicación de su patología cardiovascular y uno por falla multisistémica. La expresividad clínica de la enfermedad fue variable.

Estudio de anomalías genéticas cromosónicas como estrategia para la investigación de genes candidatgos en niños con trastornos del espectro Autista / Study of genetic anomalies cromosónicas like strategy for the investigation of genes candidatgos in children with disorders of the Autistic spectrum

El autismo fue descripto en 1943 por Leo Kanner. Los Trastornos del Espectro Autista constituyen un amplio grupo de perturbaciones graves y generalizadas de diferentes áreas del desarrollo, caracterizadas por alteraciones en la interacción social, en la comunicación y conductas e intereses repetitivos y estereotipados. Actualmente diferentes métodos están siendo empleados para elucidar la asociación entre genes específicos y autismo. La detección de anomalías cromosómicas en individuos con Trastornos del Espectro Autista, contribuyen a establecer regiones donde se localizan genes específicos, potencialmente asociados con la producción de esta sintomatología.El objetivo de este trabajo fue estudiar las anomalías cromosómicas presentes en una serie de niños con diagnóstico de Trastornos del Espectro Autista, con la finalidad de establecer la prevalencia relativa y proponer regiones donde potencialmente se localicen genes candidatos, relacionados con autismo.Se estudiaron 46 niños, hasta 18 años de edad, con diagnóstico confirmado de Trastornos del Espectro Autista según criterios del Manual diagnóstico y estadístico de trastornos mentales, 4º edición (DSM IV). Se encontró una prevalencia relativa de anomalías cromosómicas del 22 por ciento, observándose además que 9 por ciento de los niños presentaban alguna patología genética no cromosómica. Se proponen como regiones candidato para el mapeo de genes de susceptibilidad para Trastornos del Espectro Autista Xq27.3; 15(q11;q13); 22q11; 2p11;2q37, datos coincidentes con publicaciones previas; y 11q23 no referida hasta el momento en relación a la sintomatología estudiada.Se observó además una mayor incidencia de polimorfismos cromosómicos en niños con Trastornos del Espectro Autista y de abortos recurrentes en la descendencia de sus progenitores.