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).

Prenatal phenotypic analysis and genetic counseling for 22q11.21 microdeletion and microduplication syndrome / 中华围产医学杂志

Objective:To analyze the prenatal clinical phenotypes and pregnancy outcomes of fetuses with 22q11.21 microdeletion and microduplication syndrome to provide a basis for clinical genetic counseling.Methods:This retrospective study involved the cases diagnosed with 22q11.21 microdeletion or microduplication by chromosomal microarray analysis (CMA) due to abnormal ultrasound findings, advanced maternal age, or high-risk pregnancies indicated by serum screening in the Prenatal Diagnosis Center of the First Affiliated Hospital of Air Force Medical University from January 2015 to January 2022. Clinical phenotypes and pregnancy outcomes of the fetuses were analyzed and described.Results:Among 9 141 cases referred for CMA during the study period, 77 cases (0.8%) were diagnosed as 22q11.21 microdeletion or microduplication, including 62 (80.5%) with 22q11.21 microdeletion and 15 (19.5%) with microduplication. In the 22q11.21 microdeletion cases, 58 had typical deletion, and four had atypical deletions, but all fetuses carried TBX1 gene that was clearly associated with congenital heart disease. The 15 fetuses with 22q11.21 microduplication including 14 in the typical region and one in the atypical region. Forty-eight (77.4%) out of the 62 fetuses with 22q11.21 microdeletion were complicated by congenital heart defects, including 28 with conotruncal defects. Five of the 15 fetuses with 22q11.21 microduplication were complicated by congenital heart defects. The cases were followed up on telephone at three to six months after the expected date of delivery. Among the 62 cases with 22q11.21 microdeletion, 52 terminated pregnancies, five were lost to follow-up, and five were delivered (one died after one month of premature delivery, one was born with anal advancement and growth retardation, and three were followed up without obvious abnormality). Among the 15 cases with 22q11.21 microduplication, four terminated pregnancies, two were lost to follow-up, and nine gave birth (eight were followed up without obvious abnormality, one grew slowly). Conclusions:The application of CMA in the prenatal diagnosis of 22q11.21 microdeletion and microduplication fetuses, and the comprehensive analysis of clinical manifestations and pregnancy outcome combined with ultrasonic diagnosis are of great significance in guiding the treatment and rehabilitation after birth of an affected child. Genetic counseling for cases with 22q11.21 microdeletion and microduplication syndrome should be cautious and consider ultrasound findings.

Prenatal diagnosis and genetic analysis of seven fetuses with 16p12.2 microdeletion or microduplication / 中华围产医学杂志

Objective:To investigate the prenatal ultrasonographic features and diagnosis of 16p12.2 copy number variation (CNV).Methods:This retrospective study recruited seven fetuses with 16p12.2 microdeletion/microduplication in the First Affiliated Hospital of Fujian Medical University from January 2017 to December 2021. Data, including the prenatal diagnostic indications, ultrasound findings, karyotypes, genetic testing and mutation tracing results, pregnancy outcomes, and postnatal follow-up data, were summarized with descriptive statistical analysis.Results:Prenatal ultrasound indicated three fetuses with structural abnormalities, including one case each of multiple malformations, interventricular septal defect, and cleft lip and palate. The other four cases were positive for ultrasonic soft markers involving the heart and kidney. The chromosome karyotypes of the seven fetuses were normal. Single nucleotide polymorphism array (SNP array) results showed that four cases had a 381.7-542.4 kb microdeletion containing three genes ( OTOA, METTL9, and IGSF6) in Online Mendelian Inheritance in Man (OMIM) at 16p12.2 (distal region) and three cases had a 484.0-701.7 kb microdeletion/microduplication containing four OMIM genes ( UQCRC2, CDR2, EEF2K, and POLR3E) at 16p12.2 (proximal region). Five (cases 1, 2, 4, 5, and 6) out of the seven fetuses inherited the variants from their phenotypically normal mother/father, and among them, three (cases 2, 4, and 5) were delivered at term and healthy. Two cases (cases 3 and 7) refused to undergo pedigree verification. Case 3, a full-term infant, underwent ventricular septal defect repair three months after birth, and no abnormality was found at 18 months of age. Conclusions:No specific phenotype presents in fetuses with 16p12.2 microdeletion/microduplication in prenatal diagnosis. OTOA gene is the key gene associated with abnormality in the distal region of 16p12.2. Pedigree analysis is conducive to preventing unnecessary termination of pregnancy.

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)

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.

Early warning of low maternal unconjugated estriol level by prenatal screening for fetus with X-linked ichthyosis / 中华妇产科杂志

Objective:To analyze the characteristic of prenatal serological screening in fetus with X-linked ichthyosis (XLI), and to explore the relationship between unconjugated estriol (uE 3) levels and XLI. Methods:A total of 56 fetuses with Xp22.31 microdeletion indicated by prenatal diagnosis and 70 fetuses diagnosed with trisomy 21 and 26 fetuses with trisomy 18 in Henan Provincial People's Hospital and Affiliated Hospital of Weifang Medical College from September 2016 to June 2021 were collected. The multiples of median (MoM) values of uE 3, alpha-fetoprotein (AFP), and human chorionic gonadotropin (hCG) during the second trimester of pregnancy were retrospectively analyzed. Prenatal diagnosis was made by amniotic fluid karyotype analysis and genome copy number variant analysis, parent genetic verification and pathogenicity analysis were performed, and maternal and infant outcomes were followed up. Results:Of 56 pregnant women with fetal Xp22.31 microdeletion, 43 underwent serological screening during the second trimester of pregnancy, of which 42 were abnormal (39 male fetuses and 3 female fetuses). The median uE 3 MoM value of 39 male fetuses [0.06 (0.00-0.21)] was lower than the normal value and significantly lower than that of fetuses with trisomy 21 [0.71 (0.26-1.27)] and fetuses with trisomy 18 [0.36 (0.15-0.84)], the difference was statistically significant ( Z=99.96, P<0.001). While the MoM values of AFP and hCG were all within the normal range. Among the 56 fetuses carrying Xp22.31 microdeletion, 45 were male fetuses and 11 were female fetuses, and the deletion fragments all involved STS gene. Eighty-nine percent (50/56) were inherited from mother (49 cases) or father (1 case), and 11% (6/56) were de novo mutations. Follow-up showed 48 live births (38 males and 10 females) and 8 chose to terminate pregnancy (7 males and 1 female). Among the 38 male newborns, 37 presented with scaly skin changes from 1 to 3 months of age, and one had no clinical manifestations until 4 months after birth. Ten female newborns had no obvious clinical manifestations. Conclusions:The decrease levels of uE 3 MoM on maternal serological screening is closely related to the higher risk of XLI in male fetuses. For pregnant women with low uE 3 in serological screening or with family history of ichthyosis, in addition to chromosomal karyotype analysis, joint detection of genomic copy number variant analysis should be recommended.

Prenatal diagnosis and genetic analysis of 9p24 microdeletion in six fetuses / 中华围产医学杂志

Objective:To investigate the prenatal diagnosis and genetic analysis of 9p24 microdeletion in six fetuses.Methods:Genetic data of six pregnant women with positive results of serological Down's syndrome screening at Henan Provincial People's Hospital from January 2018 to January 2020 were retrospectively collected and analyzed. Amniotic fluid and the parents' peripheral blood samples were subjected to G banding and array comparative genomic hybridization (aCGH) analysis. Detected copy number variation (CNV) were classified based on the American College of Medical Genetics and Genomics (ACMG) scoring standard.Results:Six fetuses showed no abnormalities in ultrasound during the second trimester as well as in karyotyping. A chromosome deletion of 1 019~6 001 kb at 9p24 was found in all six fetuses by aCGH, referring to disease-related genes DMRT1, SMARCA2, DOCK8, etc. The deletion of case 3 was inherited from the asymptomatic father, and the other fetal five were all de novo mutations. Cases 1, 2, 5, and 6 were pathogenic/likely pathogenic CNV carriers and cases 3 and 4 were CNV of unknown clinical significance carriers. After genetic counseling, cases 1, 2, 5, and 6 chose to terminate the pregnancies; cases 3 and 4 continued and gave birth to normal offspring. Conclusions:Fetuses with 9p24 microdeletion lack specific phenotypes before born. DMRT1 and SMARCA2 may be the key genes in this region.

Prenatal diagnosis and pregnancy outcomes of 17 fetuses with 16p13.11 microdeletion syndrome / 中华围产医学杂志

Objective:To investigate the association between prenatal genotype and phenotype of 16p13.11 microdeletion syndrome, aiming to provide a reference for prenatal diagnosis and genetic counseling.Methods:This retrospective study analyzed the results of comparative genomic hybridization microarray and low-coverage whole genome sequencing performed on 4 230 pregnant women in the Henan Provincial People's Hospital from July 2018 to July 2021. Indications for prenatal diagnosis, pedigree information and pregnancy outcomes of 17 fetuses with 16p13.11 microdeletion were described.Results:Prenatal diagnostic indications in the 17 fetuses were ultrasound abnormalities in five cases (increased nuchal translucency in four and cerebral ventriculomegaly with 10.7 mm in one), inter-twin weight discordance over 20% in one case, high risk in five cases and marginal risk in one in trisomy-21 serum screening, advanced maternal age in three cases (one with echogenic intracardiac focus in the left ventricle and two with normal ultrasound images) and adverse pregnancy history in two cases with normal ultrasound images. Pedigree verification that performed on 12 cases revealed that five were caused by de novo mutations and seven were inherited from their parents. The follow-up results showed that five cases were terminated, two lost to follow-up and 10 born alive (inheritance patterns were de novo mutations in three cases, parental inheritance in six and unknown pattern in one). These 10 infants were followed up from age 7 months to 3 years and 2 months and the results showed that one case was born with choroid plexus cyst of the left ventricle and presented instability of gait at 1 year and 3 months; one was a premature infant with 33 gestational weeks whose parents reported his language ability was not well at 2 years and 1 month old but without other abnormalities; one case had low muscle tone and was unable to keep head upright at 3 months who recovered at 5 months old after rehabilitation treatment according to the parents' report; all seven parents in the remaining seven cases reported no abnormalities. Conclusions:There was no specific prenatal diagnostic indication for 16p13.11 microdeletion syndrome. Genetic tracing, pregnancy outcome analysis and follow-up surveillance would provide reference for genetic counseling of 16p13.11 microdeletion syndrome.

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.

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.

Prenatal diagnosis of fetal 1p32p31 microdeletion syndrome: a case report / 中华围产医学杂志

We hereby reported a fetus with abnormal head shape, ventricular septal defect, gallbladder enlargement, low-set ears and local umbilical cord glial edema at 22 and 25 weeks of gestation ultrasound scan. A 15.318 Mb heterozygous microdeletion on chromosome 1p32.1p31.1, arr[GRCh37]1p32.1p31.1(61,279,239-76,597,189)×1, was indentified by chromosomal microarray analysis. The chromosome karyotype of the fetus was 46,XY,del(1)(p32.1p31.1). Therefore, this case was diagnosed as 1p32p31 microdeletion syndrome and proved to be a de novo variation based on routine G-banding analysis and chromosomal microarray analysis of the normal parents. This syndrome might present with abnormalities in the head shape, kidney, bladder and central nervous system. The couple decided to terminate the pregnancy after genetic counseling concerning the possible poor outcomes of the fetus.

Prenatal diagnosis of two fetuses with renal structural anomalies caused by 17q12 deletion syndrome / 中华围产医学杂志

Objective@#To analyze the prenatal clinical characteristics and genetic diagnosis of two fetuses with chromosome 17q12 deletion syndrome mainly manifested by renal structural abnormalities.@*Methods@#Clinical data of two pregnant women admitted to Peking University First Hospital in 2017 due to ultrasound indication of fetal kidney structure abnormality in the second trimester were collected. Results of fetal chromosome karyotype analysis and array-based comparative genomic hybridization (aCGH), and aCGH detection of peripheral blood in the two couples were reviewed.@*Results@#(1) In both pregnancies of case 1 and case 2, no abnormal chromosome karyotype was found. In case 2, the fetal fluorescence in situ hybridization (FISH) results showed no abnormality. (2) During the first pregnancy of case 1, there was a 1.351 Mb of single-copy deletion in chromosome 17q12 (34 817 422-36 168 104) and a 1.187 Mb of single-copy duplication in chromosome 3p26.3 (838 934-2 026 269) extracted from umbilical cord blood. Moreover, a 1.299 Mb of single copy duplication in chromosome 3p26.3 (726 645-2 026 269) extracted from maternal peripheral blood was detected. (3) DNA analysis of the umbilical cord blood of case 2 showed a 1.351 Mb of single copy deletion in 17q12. No abnormal copy number variants (CNVs) were detected in the peripheral DNA of the couple.@*Conclusions@#Invasive prenatal detection of CNVs in cases with abnormal fetal kidney ultrasound findings might help to confirm the diagnosis and guide genetic counseling.

Clinical pathway selection based on chromosomal microarray analysis in prenatal diagnosis / 中华围产医学杂志

Chromosomal microarray analysis (CMA) is an emerging approach in prenatal diagnosis.Apart from accurate identification of the number of chromosomes and major chromosomal aneuploidy,CMA can also be used to detect submicroscopic changes such as chromosomal microdeletions and microduplications with high-resolution,short turnaround time and objectivity.However,CMA is limited in detecting balanced translocation,inversion of chromosomes and low-level mosaicism.This review summarized three clinical situations where CMA is mainly applied:fetus with certain structural abnormalities in ultrasound scan,high-risk gravidas identified by non-invasive prenatal testing and general screening for all for prenatal diagnosis.

Prenatal diagnosis and genetic analysis of increased fetal nuchal translucency due to 2p15-16.1 microdeletion: a case report / 中华围产医学杂志

We reported the prenatal molecular diagnosis and pregnant outcome of a fetus with increased nuchal translucency.The ultrasound findings of the gravida at 12+5 gestational weeks indicated that the fetal nuchal translucency thickness was 4.5 mm,and non-invasive prenatal testing suggested as low risk.Amniocentesis was performed at 18 gestational weeks.Fetal chromosomal karyotype was normal but chromosome microarray comparative genomic hybridization analysis identified a 1.878 Mb deletion on chromosome 2p15-16.1.No copy number variation was found in the parents.The microdeletion was also verified by multiplex ligation-dependent probe amplification.Literature reported that chromosome 2p 15-16.1 microdeletion syndrome was characterized by mental retardation,language developmental disorder,microcephaly and so on.This case we reported here was a de novo 2p 15-16.1 microdeletion which contained the critical region and genes of 2p 15-16.1 microdeletion syndrome and was inferred to be a pathogenetic mutation.The gravida chose to terminate the pregnancy after genetic consultation.

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.

Prenatal diagnosis of two fetuses with renal structural anomalies caused by 17q12 deletion syndrome / 中华围产医学杂志

Objective To analyze the prenatal clinical characteristics and genetic diagnosis of two fetuses with chromosome 17q12 deletion syndrome mainly manifested by renal structural abnormalities. Methods Clinical data of two pregnant women admitted to Peking University First Hospital in 2017 due to ultrasound indication of fetal kidney structure abnormality in the second trimester were collected. Results of fetal chromosome karyotype analysis and array-based comparative genomic hybridization (aCGH), and aCGH detection of peripheral blood in the two couples were reviewed. Results (1) In both pregnancies of case 1 and case 2, no abnormal chromosome karyotype was found. In case 2, the fetal fluorescence in situ hybridization (FISH) results showed no abnormality. (2) During the first pregnancy of case 1, there was a 1.351 Mb of single-copy deletion in chromosome 17q12 (34 817 422-36 168 104) and a 1.187 Mb of single-copy duplication in chromosome 3p26.3 (838 934-2 026 269) extracted from umbilical cord blood. Moreover, a 1.299 Mb of single copy duplication in chromosome 3p26.3 (726 645-2 026 269) extracted from maternal peripheral blood was detected. (3) DNA analysis of the umbilical cord blood of case 2 showed a 1.351 Mb of single copy deletion in 17q12. No abnormal copy number variants (CNVs) were detected in the peripheral DNA of the couple. Conclusions Invasive prenatal detection of CNVs in cases with abnormal fetal kidney ultrasound findings might help to confirm the diagnosis and guide genetic counseling.

Chromosomal microarray analysis of 339 fetuses with increased nuchal translucency and normal karyotype / 中华围产医学杂志

Objective To explore the value of chromosome microarray analysis (CMA) in determining the genetic etiology of fetuses with increased nuchal translucency (NT) but normal karyotype. Methods Amniocentesis, karyotype analysis and CMA were performed to singleton pregnant women with increased fetal NT ( ≥ 3.0 mm) in early pregnancy (11+1-13+6 gestational weeks) at Shenzhen Maternity and Child Healthcare Hospital from March 2015 to December 2017. A total of 339 fetuses with normal G banding karyotype analysis were recruited retrospectively. Peripheral blood samples were collected for CMA in parents whose fetuses were detected with pathogenic copy number variations (CNVs) or variants of uncertain significance (VUS). Descriptive analysis was used for CMA results. Moreover, Pregnancy outcomes and postnatal conditions of fetuses with abnormal CNVs were followed up. Results Pathogenic CNVs, ranging from 68 kb to 12.636 Mb, were detected in 15 out of the 339 fetuses (4.4%) including four microduplications and 11 microdeletions. Among them, there were eight known microdeletion or microduplication syndromes (nine cases) including Williams-Beuren syndrome, 18p deletion syndrome,Wolf-Hirschhorn syndrome, 22q11 duplication syndrome, 16p11.2 deletion syndrome, 17p13.3 duplication syndrome, 16p11.2 duplication syndrome (one case respectively) and DiGeorge syndrome/velocardiofacial syndrome (two cases). Of the 11 fetuses with VUS, five cases originated from parents with normal phenotype and the identified VUS were benign and the rest six were de novo mutations[1.8%(6/339)]. Of the 15 fetuses with pathogenic CNVs, one was lost to follow-up, four were live born and two of which was found to be growth retardation at the age of two. Among the 11 fetuses with VUS, nine were live born and no abnormality was reported in any cases at one year old. Conclusions For fetus with increased NT and normal karyotype, CMA is able to identify chromosomal microdeletion/microduplication that are not recognized by conventional karyotyping analysis, and may play an important role in prenatal diagnosis and genetic counseling.

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.