[20q11.2 microdeletion syndrome: a phenotypic spectrum expansion. Case report]. / Síndrome de microdeleción 20q11.2: ampliación del espectro fenotípico. Reporte de un caso.

Background: 20q11.2 microdeletion syndrome [ORPHA: 444051] is a rare disease, since 16 patients have been reported in literature worldwide. Prevalence ratio is < 1:1,000,000 individuals. Haploinsufficiency on GDF5, SAMHD1 and EPB41L1 genes is important due to phenotypic manifestations in patients. Clinical features can be grouped into craniofacial abnormalities, limb abnormalities, neurological and perinatal disorders. The aim of this report is to present a clinical case of 20q11.21-q11.23 microdeletion, to describe clinical manifestations found, to compare them with features reported in literature, and to contribute to the phenotypic spectrum expansion. Clinical case: 5-year-old female patient who presented hypotonia, psychomotor retardation, microcephaly, facial dysmorphia, pectus excavatum, thoracolumbar scoliosis, right hip subluxation, camptodactyly and clinodactyly. Karyotype test was normal and SNP microarray test reported deletion of chromosomal region 20q11.21-q11.23. Conclusions: It was presented a 20q11.2 microdeletion syndrome confirmed case that shares the features reported in literature, in addition to previously unreported features, such as blepharoptosis, pectus excavatum, scoliosis and hip dysplasia. Interdisciplinary management is important to improve the patient's condition (in her 3 spheres), in order to achieve her best possible health status.

Introducción: el síndrome de microdeleción 20q11.2 [ORPHA: 444051] es una enfermedad rara, pues se han reportado 16 casos a nivel mundial. Su prevalencia se estima en < 1:1,000,000 de nacidos vivos. Induce haploinsuficiencia en los genes GDF5, SAMHD1 y EPB41L1, los cuales son de importancia clínica por las manifestaciones fenotípicas. Se caracteriza por anomalías craneofaciales, anomalías de extremidades, alteraciones neurológicas y perinatales. El objetivo de este reporte es presentar un caso de microdeleción 20q11.21-q11.23, describir las manifestaciones clínicas encontradas, compararlo con lo reportado en la literatura y colaborar en la ampliación del espectro fenotípico. Caso clínico: paciente del sexo femenino de 5 años que presentó hipotonía, retraso psicomotor, microcefalia, dismorfias faciales, pectus excavatum, escoliosis toracolumbar, subluxación de cadera derecha, camptodactilia y clinodactilia. La prueba de cariotipo se reportó sin alteraciones y el ensayo de microarreglo de polimorfismos de un nucleótido (SNP) reportó deleción de la región cromosómica 20q11.21-q11.23. Conclusiones: se presentó un caso confirmado de síndrome de microdeleción 20q11.2 que comparte las características reportadas en la literatura, además de características no reportadas previamente, como ptosis palpebral, pectus excavatum, escoliosis y displasia del desarrollo de cadera. Es importante el manejo interdisciplinario para buscar mejoría en la condición de la paciente (en sus 3 esferas), a fin de alcanzar el mejor estado de salud posible.

A20 haploinsufficiency in a neonate caused by a large deletion on chromosome 6q.

Haploinsufficiency of A20 (HA20) is a rare monogenic disease caused by heterozygous loss-of-function mutations in the tumor necrosis factor alpha-induced protein 3 (TNFAIP3) gene located on chromosome 6q23.3. The majority of disease-causing mutations in most cases of HA20 comprise single nucleotide variations, small insertions, or deletions in TNFAIP3, which result in a premature termination codon and subsequent disruption of its anti-inflammatory role. Large deletions have been reported sporadically. HA20 patients may present with a variety of autoinflammatory and autoimmune features during early childhood; however, cases with neonatal onset are rare. Here, we describe a Chinese neonate presenting with concomitant inflammatory and other syndromic manifestations caused by a 5.15 Mb interstitial deletion in chromosome 6; these deletions affect TNFAIP3. Taken together, the data extend the clinical and genetic spectra of HA20.

Síndrome de microdeleção 2q32 em paciente da Amazônia ocidental / 2q32 microdeletion syndrome in a patient from the western Amazon

Introdução: As deleções intersticiais envolvendo a região 2q31q32 são reconhecidas como um transtorno clínico, envolvendo diversas manifestações como deficiência intelectual, retardo no crescimento, distúrbios comportamentais e dismorfologias faciais. Os números reduzidos de relatos de pacientes acometidos por essa síndrome contribui para que as correlações genótipos-fenótipos sejam difíceis de se fazer. Relato de caso: Paciente com inversão do braço longo do cromossomo 2 [46, XX,inv(2)(q21q33)]. Apresentou ao exame físico dismorfológico fronte proeminente, epicanto, ponte nasal baixa, filtro nasolabial longo e lábio superior fino. Ao exame neurológico, apresentava hipotonia. Discussão: Uma correta interpretação cromossômica pode não só identificar a síndrome de microdeleção como também, descartar ou confirmar possíveis diagnósticos diferenciais, deixando evidente a necessidade e a importância de se reconhecer e documentar os casos (AU).

Introduction: Interstitial deletions involving the 2q31q32 region are recognized as a clinical disorder involving several manifestations, such as intellectual disability, growth retardation, behavioral disorders, and facial dysmorphologies. The reduced number of reports of patients affected by this syndrome contributes to the difficulty of making genotype-phenotype correlations. Case report: Patient with inversion of the long arm of chromosome 2 [46, XX,inv(2)(q21q33)]. On physical examination, he had a prominent forehead, epicanthus, low nasal bridge, long nasolabial philtrum and thin upper lip. Neurological examination showed hypotonia. Discussion: A correct chromosomal interpretation can identify the microdeletion syndrome and rule out or confirm possible differential diagnoses, highlighting the need and importance of recognizing and documenting cases (AU).

Novel 12 Mb interstitial deletion of chromosome 8p11.22-p21.2: a case report.

BACKGROUND: The deletion of a short arm fragment on chromosome 8 is a rare cause of Kallmann syndrome and spherocytosis due to deletion of the FGFR1 and ANK1 genes. CASE PRESENTATION: This case study describes a 4-month-old child with growth and psychomotor retardation, auricle deformity, microcephaly, polydactyly, a heart abnormality, and feeding difficulties. An approximately 12.00 MB deletion was detected in the 8p11.22-p21.2 region of chromosome 8. After sequencing, we found that 65 protein genes had been deleted, including FGFR1, which resulted in Kallmann syndrome. There was no deletion of the ANK1 gene associated with spherocytosis, consistent with the phenotype. CONCLUSION: This patient is a new case of short arm deletion of chromosome 8, resulting in novel and previously unreported clinical features.

Terminal deletion of the short arm of chromosome 6 (6P25 3P 243): a literature review and case report of a Brazilian child / Deleção terminal do braço curto do cromossomo 6 (6p25 3p 243): uma revisão de literatura e relato de caso de uma criança brasileira

Introduction: Deletion syndromes are rare events in clinical practice. A chromosomal deletion occurs when seg-ments of genetic information are missing on a particular chromosome or more. The absence of some genes implies varied phenotypes, which detailed explanation is not fully elucidated yet. Objective: Report the case of a child with a terminal segment deletion of 8,9 Mb on the short arm of chromosome 6 (in 6p25.3p24.3) Methods: This case report was approved by the Ethics and Research Committee of the institution. For its preparation, the exam data provided by the patient's family were added from prenatal to early childhood and the discussion with professionals related to the case. Results: B.A.G., a two-year-old female child, the only daughter of non-consanguineous par-ents, no family history of similar diseases. She was born by premature cesarean section (GA: 35 weeks), presenting Dandy-Walker malformation, Fallot tetralogy, head circumference in the 97th percentile, and syndromic facies, with hypertelorism, low implantation of the ears, and opacity of both lenses. Conclusion: Deletions on chromosome 6 are a very rare genetic alteration. Until 2004, there were only 43 cases in the medical literature, excluding ring chromosome 6 anomalie31. Regarding the terminal deletions of the short arm, this case specifically - 6p24pter - was associated with developmental delay, brain malformations, abnormalities in the anterior chamber of the eye, hearing loss, and abnormalities in the ear, micrognathia, and heart diseases (AU)

Introdução: As síndromes de deleção são eventos raros na prática clínica. A deleção cromossômica ocorre quando segmentos de informação genética são perdidos em um ou mais cromossomos. A ausência de alguns genes implica em fenótipos variados, cuja explicação detalhada ainda não está totalmente elucidada. Objetivo: Relatar o caso de uma criança com deleção de segmento terminal de 8,9 Mb do braço curto do cromossomo 6 (em 6p25.3p24.3) Métodos: Esse relato de caso foi aprovado pelo Comitê de Ética e Pesquisa da Instituição. Para sua elaboração, foram adicionados os dados de exames fornecidos pela família do paciente desde o pré-natal até a primeira infância e a discussão com profissionais relacionados ao caso. Descrição do Caso: B.A.G., criança de dois anos, sexo femi-nino, filha única de pais não consanguíneos, sem antecedentes na família de doenças similares. Nasceu por cesárea prematura (IG 35 semanas), apresentando Síndrome de Dandy-Walker, tetralogia de Fallot, perímetro cefálico no percentil 97 e fácie sindrômica, com hipertelorismo, baixa implantação das orelhas e opacidades do cristalino bi-lateralmente. Conclusão: As deleções no cromossomo 6 são alterações genéticas de grande raridade. Até 2004, existiam apenas 43 casos na literatura médica, excluindo a anomalia do cromossomo 6 em anal 31. No que se refere às deleções terminais do braço curto, a do caso em questão - 6p24-pter - foram associadas o atraso no desenvol-vimento, malformações cerebrais, anormalidades na câmara anterior do olho, perda auditiva, anormalidades no ouvido, micrognatia e cardiopatias (AU)

Bioinformatics analysis of recurrent deletion regions in neuroblastoma.

Neuroblastoma (NB) is the most common extra-cranial solid tumor in childhood. Very few genes in recurrent deletion regions have been identified as tumor suppressors for NB, and interactions among proteins encoded by genes in these regions have been overlooked. This study aims to identify possible tumor suppressor genes located within regions commonly deleted in NB tumors and to show possible interaction network of proteins encoded by genes in these regions by bioinformatics analysis. The genes localized in the recurrent deletion regions were identified using the Ensembl BioMart web-tool. GSE1824 microarray dataset was analyzed to determine downregulated differently expressed genes (dDEGs) selected from deletion regions using Orange Canvas software. The DAVID v6.8 tool and Reactome database were used to perform gene ontology and pathway enrichment analysis, respectively. The protein-protein interaction (PPI) network and sub-module analysis were conducted by STRING database and Cytoscape plugin MCODE software, respectively. Copy number variation status and mutations of hub genes were examined in TARGET neuroblastoma dataset using UCSC Xena platform. Biological processes of genes were specific to chromosomes. The 219 genes selected from these regions were found to be downregulated. A PPI network was constructed for dDEGs. Copy number losses and mutations were observed for hub genes. Hub genes identified in the current study may act as tumor suppressors in NB tumorigenesis. Disruption of protein-protein interaction network consisting of proteins encoded by genes on various recurrent deletion regions may give rise to NB by interrupting gene regulatory network orchestrating neural crest formation.

Investigação Citogenômica de Crianças com Doença Cardíaca Congênita: Experiência de um Centro no Brasil / Cytogenomics Investigation of Infants with Congenital Heart Disease: Experience of a Brazilian Center

Resumo Fundamento Algumas síndromes têm características específicas e facilmente reconhecíveis, enquanto outras podem ser mais complexas de se identificar e podem apresentar diferentes manifestações fenotípicas, por exemplo. Um diagnóstico etiológico é importante para entender a natureza da doença, para estabelecer o prognóstico e para começar o tratamento, permitindo a inclusão de pacientes na sociedade e reduzindo o custo financeiro dessas doenças. Objetivo A proposta inicial deste estudo foi a triagem citogenética para detectar a síndrome de deleção 22q11.2 (SD22q11.2) em recém-nascidos e crianças com doença cardíaca congênita utilizando a técnica da amplificação multiplex de sondas dependente de ligação (MLPA). Assim, por meio da pesquisa, outras mudanças genômicas foram identificadas nesses pacientes cardíacos. Nosso objetivo se estendeu a investigar essas outras mudanças citogenéticas. Métodos Investigamos 118 recém-nascidos com doenças cardíacas congênitas nascidos consecutivamente durante um ano, utilizando a técnica da MLPA. Resultados A técnica da MLPA permitiu a detecção da SD22q11.2 em 10/118 pacientes (8,5%). Outras alterações genômicas foram identificadas em 6/118 pacientes (5%): 1p36 del, 8p23 del (2 casos), 7q dup, 12 dup e 8q24 dup. Conclusão Este estudo ressalta a relevância da detecção de alterações genômicas que estão presentes em recém-nascidos e crianças com doenças cardíacas congênitas por meio de ferramentas citogenômicas.

Abstract Background Some syndromes have specific and easily recognizable features, while others may be more complex to identify and may present different phenotypic manifestations, for example. An etiological diagnosis is important to understand the nature of the disease, to establish the prognosis and to start the treatment, allowing the inclusion of patients in society and reducing the financial cost of such diseases. Objective The initial proposal of this study was cytogenetic screening for the detection of the 22q11.2 deletion syndrome in consecutive newborns and infants with congenital heart disease using the multiplex ligation-dependent probe amplification (MLPA) technique. Therefore, throughout our research, other genomic alterations were identified in these cardiac patients. Thus, our objective was extended to investigate these other cytogenetic alterations. Methods We investigated 118 neonates with congenital heart diseases born consecutively during one year using the MLPA technique. Results The MLPA technique allowed the detection of 22q11.2DS in 10/118 patients (8.5%). Other genomic alterations were also identified in 6/118 patients (5%): 1p36 del, 8p23 del (2 cases), 7q dup, 12 dup and 8q24 dup. Conclusion This study highlights the relevance of detecting genomic alterations that are present in newborns and infants with congenital cardiac diseases using cytogenomic tools.

An Intradermal Spindle Cell Lipoma on the Plantar Hallux in a Patient With Scleroderma and Ehlers-Danlos Syndrome: A Case Report.

Spindle cell lipoma (SCL) is a rare variant of lipomas, which predominantly occurs in the regions of shoulder and posterior neck but rarely on the toes. Epidemiological studies have demonstrated increased incidence of cancers in patients with scleroderma. A 28-year-old female with scleroderma and Ehlers-Danlos syndrome developed a painful, skin colored, raised, polypoid lesion on the plantar side of the left hallux for several years. The lesion was surgically excised. Pathological evaluation showed intradermal bland spindle cells associated with delicate ropey/refractile collagen bundles with strong and diffuse cytoplasmic expression of CD34 but negative expression of Rb and S-100, which are consistent with SCL. We report a first case of SCL on the plantar hallux in a young female patient with scleroderma and Ehlers-Danlos disease with clinical presentations, histopathology, and treatment to raise awareness of clinicians to this rare variant of lipomas.

Mono-allelic loss of YTHDF3 and neurodevelopmental disorder: clinical features of four individuals with 8q12.3 deletions.

The YTH domain family member 3 gene (YTHDF3) encodes a reader of the abundant N6-methyladenosine (m6 A) modification of eukaryotic mRNA, which plays an essential role in regulating mRNA stability and is necessary to achieve normal development of the central nervous system in animal models. YTHDF3 has not previously been implicated in Mendelian disease despite a high probability of loss of function intolerance and statistical evidence of enrichment for gene-disruptive de novo variants in large-scale studies of individuals with intellectual disability and/or developmental delay. We report four individuals with deletion of 8q12.3, deletion size 1.38-2.60 Mb, encompassing YTHDF3, three of them were de novo, and in one case, the inheritance was unknown. Common features of the individuals (age range, 4-22 years) were developmental delay and/or intellectual disability. Two individuals underwent squint surgery. We suggest that haploinsufficiency of YTHDF3 causes a neurodevelopmental disorder with developmental delay and intellectual disability of variable degree.

Detection of deletions in 1q25, 1p36 and 1pTEL and chromosome 17 aneuploidy in oral epithelial dysplasia and oral squamous cell carcinoma by fluorescence in situ hybridization (FISH).

OBJECTIVE: To identify chromosome deletions in 1q25, 1p36 and 1pTEL, and chromosome 17 ploidy status in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: Samples from 57 OED and 63 OSCC were selected. FISH was performed using centromeric probes 17 and n LSIR 1p36/LSI 1q25 Dual Color Probe. RESULTS: In OED, deletions were found only in 1pTEL region (29.8%). In OSCC, there was a higher frequency of deletion in 1pTEL (79.4%), followed by 1p36 (73.0%), and 1q25 (20.6%). Advanced TNM clinical stages (III/IV) showed all the deletions studied; at early clinical stages (I/II) of OSCC, deletions were observed only in 1pTEL. The frequency of deletion in 1p36 was 17.0 times higher in OSCC at advanced clinical stages (PR: 17.00). The median number of cell nuclei with chromosome 17 aneuploidy was higher in OSCC than in OED (P < 0.001). Early clinical stages of OSCC showed lower median number nuclei with aneuploidy when compared to advanced tumors (P < 0.05). Tumors harboring deletions in 1p36, 1q25 and 1pTEL revealed higher median numbers of trisomic/polysomic nuclei when compared to lesions exhibiting no abnormalities in chromosome 1 (P < 0.05). CONCLUSION: A higher prevalence of chromosomal abnormalities was found in OSCC than in OED, while in OSCC, higher abnormalities were present in lesions with higher TNM staging. 1pTEL deletion and monosomy of chromosome 17 are possible markers for progression of OED to OSCC. 1p36 deletion and trisomy/polysomy of chromosome 17 could be markers of worse prognosis of OSCC.

Genetic analysis of products of conception. Should we abandon classic karyotyping methodology? / Análise genética dos produtos de concepção. Devemos abandonar a metodologia de cariotipagem clássica?

ABSTRACT Objective: To compare the results obtained by the classic and molecular methodology in the analysis of products of conception, the advantages and disadvantages of each method. Methods: Retrospective non-randomized analysis of results obtained from product of conception samples submitted to genetic evaluation, from 2012 to 2017. The evaluations were performed using cytogenetics and/or chromosomal microarray analysis or arrays. Results: Forty samples were analyzed using classic cytogenetics, of which 10% showed no cell growth, 50% had normal results and 40% had abnormalities. Of the 41 cases sent for array analysis it was not possible to obtain results in 7.3%, 39.5% were normal and 60.5% had abnormalities. There was no statistical difference among the results (p=0.89). Most abnormal results were seen till 9 weeks' gestation. The later abnormal miscarriage was seen at 28 weeks' gestation, with karyotype 46,XX,del(15)(q26.2-qter). The results are corroborated by the international literature. Conclusion: Classic cytogenetics and array techniques showed comparable results on the type of alteration observed. Array analysis is preferable to cell culture in delayed abortions, while cytogenetics is more able to show polyploidies. Both have the same growth failure rates when product of conception tissue is not properly collected.

RESUMO Objetivo: Comparar os resultados obtidos pela metodologia clássica e molecular na análise de produtos de concepção, além das vantagens e desvantagens de cada método. Métodos: Análise retrospectiva não randomizada dos resultados obtidos a partir de amostras de produto de concepção submetidas à avaliação genética, de 2012 a 2017. As análises foram realizadas por citogenética clássica e/ou análise cromossômica de microarray ou arrays. Resultados: Quarenta amostras foram analisadas por citogenética, das quais 10% não apresentaram crescimento celular, 50% apresentaram resultados normais, e 40% apresentaram anormalidades. Dos 41 casos encaminhados para análise por array, não foi possível obter resultados em 7,3%, 39,5% eram normais, e 60,5% apresentavam alterações. Não houve diferença estatística entre os resultados (p=0,89). A maioria dos resultados anormais foi observada até a nona semana de gestação. Uma perda fetal mais tardia foi observada na 28ª semana de gestação, com cariótipo 46,XX,del(15)(q26.2-qter). Os números observados corroboraram a literatura mundial. Conclusão: As técnicas de citogenética clássica e análise por array mostraram resultados comparáveis no tipo de alteração observada. O array é preferível à cultura de células em abortos tardios, enquanto a citogenética é mais capaz de mostrar poliploidias. Ambos têm as mesmas taxas de falha de crescimento quando o tecido do produto de concepção não é coletado adequadamente.

Congenital Heart Disease Revealing Familial 22q11 Deletion Syndrome

Abstract Congenital heart defects are the most common birth defects and the leading cause of mortality in the first year of life. It is well known that the 22q11 deletion syndrome (22q11DS) is the most common microdeletion syndrome in humans and that congenial heart diseases (CHDs) are one of the most common phenotypic manifestations. However, it should be noted that the 22q11 deletion was also found in a significant number of patients with isolated CHD. The 22q11DS phenotype may include cardiovascular anomalies, palatal abnormalities, nasal voice, immune deficiency, endocrine dysfunctions, a varying degree of cognitive deficits and intellectual disabilities, velopharyngeal insufficiency, and characteristic craniofacial dysmorphism. This condition affects about 1 in 4,000 live births, making 22q11DS the most common microdeletion syndrome in humans. Here we describe the cases of three children who were referred to the clinical hospital center with the diagnosis of CHD, but with no direct signs of 22q11DS. Investigation of familial data led us to suspect that the mothers could be carriers of 22q11DS. The multiplex ligation-dependent probe amplification (MLPA) testing confirmed that the patients and mothers exhibited 3 Mb 22q11 deletions, which justified the clinical signs in the mothers and the CHD in children. In the presence of a few characteristics that are common of a spectrum of some known syndromes, a familial examination can provide clues to a definitive diagnosis, as well as to the prevention of diseases and genetic counseling of these patients.

Breast cancer in six families from Tolima and Huila: BRCA1 3450del4 mutation / [Cáncer de mama en seis familias del Tolima y el Huila: mutación BRCA1 3450del4].

Introduction: Breast cancer is a worldwide public health problem; between 5% and 10% of the cases present familial aggregation explained by genes of high risk such as BRCA1 and BRCA2. The founding origin of the deletion BRCA1 3450del4 in Colombia has been previously reported. Objective: To carry out in six families from Tolima and Huila departments a descriptive analysis of the presence of the BRCA1 3450del4 mutation associated with breast cancer and familial aggregation. Materials and methods: We conducted a descriptive and cross-sectional study of six index cases with breast cancer positive for BRCA1 3450del4 that fulfilled three of the criteria established by Jalkh, et al. The genealogical trees were made using the information of the interview data (GenoPro™, version 2016). The mutation was typified in healthy and affected relatives who agreed to participate. Results: Thirty of the 78 individuals selected by convenience in the six families presented the mutation BRCA1 3450del4 six of whom developed breast cancer, one, ovarian cancer, one ovarian and breast cancer, and one prostate cancer; 21 did not present any type of neoplasm at the time of the study. Of the 30 individuals carrying the pathogenic variant, six were men, 24 were women, and 13 of these were under 30. Conclusions: In this study of families with the deletion BRCA1 3450del4 in Tolima and Huila we confirmed its association with familial aggregation of breast cancer.

Introducción. El cáncer de mama es un problema mundial de salud pública; entre el 5 y el 10 % de los casos presentan agregación familiar, lo que se explicaría por la presencia de mutaciones en genes de alto riesgo como el BRCA1 y el BRCA2. El origen fundador de la deleción BRCA1 3450del4 en Colombia ya fue reportado. Objetivo. Hacer un análisis descriptivo de seis familias del del Tolima y del Huila con la deleción BRCA1 3450del4 de la asociación de la mutación germinal, con el cáncer de mama y la agregación familiar. Materiales y métodos. Se hizo un estudio descriptivo y transversal de seis casos índice con cáncer de mama positivos para BRCA1 3450del4, que cumplían tres de los criterios establecidos por Jalkh, et al. A partir de la información de las entrevistas, se realizaron los árboles genealógicos (GenoPro™, versión 2016). Se tipificó la mutación en familiares sanos y afectados que aceptaron participar. Resultados. De los 78 individuos seleccionados por conveniencia en las seis familias, 30 presentaron la mutación BRCA1 3450del4; de ellos, seis tenían cáncer de mama, uno, cáncer de ovario, uno, cáncer de mama y ovario, y otro, cáncer de próstata; 21 no presentaban neoplasias. De los 30 individuos portadores de la variante patogénica, seis eran hombres y 24 mujeres, 13 de ellas menores de 30 años. Conclusiones. En este estudio se confirmó la asociación de la deleción BRCA1 3450del4 con el cáncer de mama de agregación familiar.

Cáncer de mama en seis familias del Tolima y el Huila: mutación BRCA1 3450del4 / Breast cancer in six families from Tolima and Huila: BRCA1 3450del4 mutation

Introducción. El cáncer de mama es un problema mundial de salud pública; entre el 5 y el 10 % de los casos presentan agregación familiar, lo que se explicaría por la presencia de mutaciones en genes de alto riesgo como el BRCA1 y el BRCA2. El origen fundador de la deleción BRCA1 3450del4 en Colombia ya fue reportado. Objetivo. Hacer un análisis descriptivo de seis familias del del Tolima y del Huila con la deleción BRCA1 3450del4 de la asociación de la mutación germinal, con el cáncer de mama y la agregación familiar. Materiales y métodos. Se hizo un estudio descriptivo y transversal de seis casos índice con cáncer de mama positivos para BRCA1 3450del4, que cumplían tres de los criterios establecidos por Jalkh, et al. A partir de la información de las entrevistas, se realizaron los árboles genealógicos (GenoPro™, versión 2016). Se tipificó la mutación en familiares sanos y afectados que aceptaron participar. Resultados. De los 78 individuos seleccionados por conveniencia en las seis familias, 30 presentaron la mutación BRCA1 3450del4; de ellos, seis tenían cáncer de mama, uno, cáncer de ovario, uno, cáncer de mama y ovario, y otro, cáncer de próstata; 21 no presentaban neoplasias. De los 30 individuos portadores de la variante patogénica, seis eran hombres y 24 mujeres, 13 de ellas menores de 30 años. Conclusiones. En este estudio se confirmó la asociación de la deleción BRCA1 3450del4 con el cáncer de mama de agregación familiar.

Introduction: Breast cancer is a worldwide public health problem; between 5% and 10% of the cases present familial aggregation explained by genes of high risk such as BRCA1and BRCA2. The founding origin of the deletion BRCA1 3450del4 in Colombia has been previously reported. Objective: To carry out in six families from Tolima and Huila departments a descriptive analysis of the presence of the BRCA1 3450del4 mutation associated with breast cancer and familial aggregation. Materials and methods: We conducted a descriptive and cross-sectional study of six index cases with breast cancer positive for BRCA1 3450del4 that fulfilled three of the criteria established by Jalkh, et al. The genealogical trees were made using the information of the interview data (GenoPro™, version 2016). The mutation was typified in healthy and affected relatives who agreed to participate. Results: Thirty of the 78 individuals selected by convenience in the six families presented the mutation BRCA1 3450del4 six of whom developed breast cancer, one, ovarian cancer, one ovarian and breast cancer, and one prostate cancer; 21 did not present any type of neoplasm at the time of the study. Of the 30 individuals carrying the pathogenic variant, six were men, 24 were women, and 13 of these were under 30. Conclusions: In this study of families with the deletion BRCA1 3450del4 in Tolima and Huila we confirmed its association with familial aggregation of breast cancer.

Síndrome de Cri du chat: primer reporte en mosaico en el suroccidente colombiano / Cri du chat syndrome: first report of mosaicism in the colombian southwest

El síndrome de Cri du chat es una alteración cromosómica causada por deleciones en el brazo corto de cromosoma 5, las cuales varían en tamaño, desde muy pequeñas que comprometen solo el locus 5p15.2, hasta la pérdida de todo el brazo corto. Las mutaciones se originan de novo en el 80% a 90% de los casos. Existen dos regiones críticas para el síndrome de Cri du chat; una ubicada en 5p15.3, cuya deleción se manifiesta con el llanto de maullido de gato y retraso en el habla, y otra ubicada en 5p15.2, cuya deleción se manifiesta como microcefalia, hipertelorismo, retraso psicomotor y mental severo. Se han descrito varios genes implicados localizados en estas regiones críticas; entre ellos, TERT, SEMA5A, CTNND2 y MARCHF6, cuya haploinsuficiencia se asocia con los diferentes fenotipos del Cri du chat. En este artículo se describe el caso clínico de una paciente femenina de 8 meses de vida, con características clínicas y un análisis citogenético en mosaico que confirmaron el síndrome de Cri du chat. Este caso es el primero reportado de esta variante en el suroccidente colombiano.

Cri du chat syndrome is a chromosomal disorder caused by deletions in the short arm of chromosome 5, which vary in size, from very small and involving only the 5p15.2 locus, to the loss of the entire short arm. Mutations originate de novo in 80% to 90% of cases. There are two critical regions for Cri du chat syndrome; one located at 5p15.3 with a deletion that is manifested as a cat's cry and speech delay, and another located at 5p15.2 with a deletion that manifests as microcephaly, hypertelorism, severe psychomotor and mental retardation. Several involved genes located in these critical regions have been described; among them, TERT, SEMA5A, CTNND2 and MARCHF6, and whose haploinsufficiency is associated with the different phenotypes of Cri du chat. This article describes the clinical case of an 8-monthold female patient, with clinical characteristics and a mosaic cytogenetic analysis that confirmed Cri du chat syndrome. This case is the first reported of this variant in southwestern Colombia.

Reclassification of Mongolian Diffuse Gliomas According to the Revised 2016 World Health Organization Central Nervous System Tumor Classification.

BACKGROUND: The 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors has been modified to incorporate the IDH mutation and 1p/19q co-deletion in the diagnosis of diffuse gliomas. In this study, we aimed to evaluate the feasibility and prognostic significance of the revised 2016 WHO classification of CNS tumors in Mongolian patients with diffuse gliomas. METHODS: A total of 124 cases of diffuse gliomas were collected, and tissue microarray blocks were made. IDH1 mutation was tested using immunohistochemistry, and 1p/19q co-deletion status was examined using fluorescence in situ hybridization analysis. RESULTS: According to the 2016 WHO classification, 124 cases of diffuse brain glioma were reclassified as follows: 10 oligodendroglioma, IDHmut and 1p/19q co-deleted; three anaplastic oligodendroglioma, IDHmut and 1p/19q co-deleted; 35 diffuse astrocytoma, IDHmut, 11 diffuse astrocytoma, IDHwt, not otherwise specified (NOS); 22 anaplastic astrocytoma, IDHmut, eight anaplastic astrocytoma, IDHwt, NOS; and 35 glioblastoma, IDHwt, NOS, respectively. The 2016 WHO classification presented better prognostic value for overall survival in patients with grade II tumors than traditional histological classification. Among patients with grade II tumors, those with oligodendroglioma IDHmut and 1p/19q co-deleted and diffuse astrocytoma IDHmut showed significantly higher survival than those with diffuse astrocytoma IDHwt, NOS (p<.01). CONCLUSIONS: Mongolian diffuse gliomas could be reclassified according to the new 2016 WHO classification. Reclassification revealed substantial changes in diagnosis of both oligodendroglial and astrocytic entities. We have confirmed that the revised 2016 WHO CNS tumor classification has prognostic significance in Mongolian patients with diffuse gliomas, especially those with grade II tumors.

Deletions of Chromosome 7q Affect Nuclear Organization and HLXB9Gene Expression in Hematological Disorders.

The radial spatial positioning of individual gene loci within interphase nuclei has been associated with up- and downregulation of their expression. In cancer, the genome organization may become disturbed due to chromosomal abnormalities, such as translocations or deletions, resulting in the repositioning of genes and alteration of gene expression with oncogenic consequences. In this study, we analyzed the nuclear repositioning of HLXB9 (also called MNX1), mapping at 7q36.3, in patients with hematological disorders carrying interstitial deletions of 7q of various extents, with a distal breakpoint in 7q36. We observed that HLXB9 remains at the nuclear periphery, or is repositioned towards the nuclear interior, depending upon the compositional properties of the chromosomal regions involved in the rearrangement. For instance, a proximal breakpoint leading the guanine-cytosine (GC)-poor band 7q21 near 7q36 would bring HLXB9 to the nuclear periphery, whereas breakpoints that join the GC-rich band 7q22 to 7q36 would bring HLXB9 to the nuclear interior. This nuclear repositioning is associated with transcriptional changes, with HLXB9 in the nuclear interior becoming upregulated. Here we report an in cis rearrangement, involving one single chromosome altering gene behavior. Furthermore, we propose a mechanistic model for chromatin reorganization that affects gene expression via the influences of new chromatin neighborhoods.

Diagnóstico molecular de distrofia muscular de Duchenne/Becker en una familia sin antecedentes patológicos de la enfermedad / Molecular Diagnosis of Duchenne/Becker muscular dystrophy in a family with no pathological antecedents of the disease

Fundamento: Las distrofias musculares de Duchenne y de Becker son enfermedades neuromusculares progresivas, con un patrón de herencia recesivo ligado al cromosoma X y causadas por mutaciones en el gen que codifica para la distrofina. El estudio de posibles portadoras en las familias afectadas resulta crucial, ya que genera expectativas y opciones frente al asesoramiento genético.Objetivos: describir el diagnóstico molecular de distrofia muscular de Duchenne/Becker en una familia sin antecedentes patológicos de la enfermedad.Métodos: se realizó un estudio experimental, de las deleciones en el gen distrofia muscular de Duchenne/Becker, en un paciente con diagnóstico clínico de la enfermedad, para lo cual se empleó la técnica de PCR-multiplex siguiendo los métodos descritos por Beggs y Chamberlain. También fueron estudiadas las mujeres de la familia, a través del análisis de marcadores polimórficos mediante repeticiones cortas en tándem de (CA)n.Resultados: fueron identificadas en el paciente deleciones de los exones 47 al 52; así como la procedencia del cromosoma X ligado a la enfermedad (abuelo materno). Se determinó el estado de no portadora en tres mujeres de la familia. No se pudo excluir mosaicismo germinal en la madre del niño.Conclusión: se infirió la ocurrencia de una mutación de novo. El diagnóstico molecular permitió la confirmación diagnóstica de la enfermedad en el niño afectado, además de la posibilidad de brindar un adecuado asesoramiento genético a la familia.

Foundation: Duchenne and  Becker muscular dystrophies are progressive neuromuscular diseases with a pattern of recessive inherited link to chromosome X and caused by mutations in the gene which codifies for dystrophin. The study of possible carriers in affected families is crucial since it generates expectations and options on genetic advisory.Objective: to describe the molecular diagnosis of Duchenne/Becker muscular dystrophy  in a family without pathological antecedents of the disease.Methods: an experimental study was developed about the deletions of Duchenne/Becker gene of muscular dystrophy, in a patient with clinical diagnosis of the disease. It was used multiple PCR technique following the methods described by Beggs and Chamberlain. In addition, the women of the family were studied by the analysis of polymorphic markers through short repetitions in (CA) n tandem.Results: deletions of exons from 47 to 52 were identified in the patient; so as the precedence of the X chromosome related to the disease (maternal grandfather). It was determined the state of non-carrier in three women of the family. It was not possible to exclude germline mosaicism in the child´s mother.Conclusion: the occurrence of a novo mutation was inferred. The molecular diagnosis allowed confirming the diagnosis of the affected child; in addition it was possible to offer adequate genetic advisory to the family.

The Role of Chromosome Deletions in Human Cancers.

Chromosome deletions are a hallmark of human cancers. These chromosome abnormalities have been observed for over than a century and frequently associated with poor prognosis. However, their functions and potential underlying mechanisms remain elusive until recently. Recent technique breakthroughs, including cancer genomics, high throughput library screening and genome editing, opened a new era in the mechanistic studying of chromosome deletions in human cancer. In this chapter, we will focus on the latest studies on the functions of chromosome deletions in human cancers, especially hematopoietic malignancies and try to persuade the readers that these chromosome alterations could play significant roles in the genesis and drug responses of human cancers.

TNFAIP3 haploinsufficiency is the cause of autoinflammatory manifestations in a patient with a deletion of 13Mb on chromosome 6.

There is scarce literature about autoinflammation in syndromic patients. We describe a patient who, in addition to psychomotor and growth delay, presented with fevers, neutrophilic dermatosis, and recurrent orogenital ulcers. Comparative Genomic Hybridization (CGH) array permitted to identify a 13.13Mb deletion on chromosome 6, encompassing 53 genes, and including TNFAIP3 gene (A20). A20 is a potent inhibitor of the NF-kB signalling pathway and restricts inflammation via its deubiquitinase activity. Western blotting and immunoprecipitation assays showed decreased A20 expression and increased phosphorylation of p65 and IkBa. Patient's cells displayed increased levels of total K63-linked ubiquitin and increased levels of ubiquitinated RIP and NEMO after stimulation with TNF. We describe the molecular characterization of an autoinflammatory disease due to a large chromosomal deletion and review the phenotypes of patients with A20 haploinsufficiency. CGH arrays should be the first diagnostic method for comprehensive analysis of patients with syndromic features and immune dysregulation.