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BACKGROUND: The 22q11.2 Deletion Syndrome (22q11.2 DS) presents unique healthcare challenges for affected individuals, families, and healthcare systems. Despite its rarity, 22q11.2 DS is the most common microdeletion syndrome in humans, emphasizing the need to understand and address the distinctive healthcare requirements of those affected. This paper examines the multifaceted issue of health service access and caregivers' quality of life in the context of 22q11.2 DS in Brazil, a condition with diverse signs and symptoms requiring multidisciplinary care. This study employs a comprehensive approach to evaluate health service accessibility and the quality of life of caregivers of individuals with 22q11.2 DS. It utilizes a structured Survey and the WHOQOL-bref questionnaire for data collection. RESULTS: Individuals with 22q11.2 DS continue to receive incomplete clinical management after obtaining the diagnosis, even in the face of socioeconomic status that enabled an average age of diagnosis that precedes that found in sample groups that are more representative of the Brazilian population (mean of 3.2 years versus 10 years, respectively). In turn, caring for individuals with 22q11.2 DS who face difficulty accessing health services impacts the quality of life associated with the caregivers' environment of residence. CONCLUSIONS: Results obtained help bridge the research gap in understanding how caring for individuals with multisystem clinical conditions such as 22q11.2 DS and difficulties in accessing health are intertwined with aspects of quality of life in Brazil. This research paves the way for more inclusive healthcare policies and interventions to enhance the quality of life for families affected by this syndrome.
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Síndrome de DiGeorge , Accesibilidad a los Servicios de Salud , Calidad de Vida , Humanos , Brasil , Masculino , Femenino , Niño , Adulto , Adolescente , Cuidadores/psicología , Preescolar , Encuestas y Cuestionarios , Adulto JovenRESUMEN
OBJECTIVE: The current study delves into the accessibility of genetic evaluations for individuals with orofacial clefts (OC), comparing data between genetics and treatment centers across Brazil. METHODS: This cross-sectional retrospective study analyzed primary data from 1463 OC individuals registered in the Brazilian Database of Craniofacial Anomalies (BDCA) between 2008 and 2018 without age or sex selection. Diagnostic exam results stemming from research projects until 2023 were considered. RESULTS: Of the 1463 individuals with typical OC, 987 were non-syndromic, 462 were syndromic (SOC), 10 presented atypical forms, and three were not specified OC cases. The average age for accessing laboratory diagnosis was 8.5 years among SOC individuals. Notably, more SOC cases were registered in genetics centers than treatment and rehabilitation centers (37.1 % vs. 29 %, p = 0.0015). Those originating from genetics centers accessed diagnosis at an average age of 7.3 years, while those from treatment and rehabilitation centers experienced delays with an average age of 10.7 years (p = 0.0581). CONCLUSIONS: Irrespective of the center of origin, the data highlight delayed diagnosis and challenges in accessing genetic tests for the syndromic group. Given the widespread reliance on the public health system by most of the Brazilian population, disseminating this data can significantly contribute to shaping an informed perspective on healthcare access. These insights can improve public policies tailored to the unique needs of individuals with OC.
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Low-pass whole genome sequencing (LP-WGS) has been applied as alternative method to detect copy number variants (CNVs) in the clinical setting. Compared with chromosomal microarray analysis (CMA), the sequencing-based approach provides a similar resolution of CNV detection at a lower cost. In this study, we assessed the efficiency and reliability of LP-WGS as a more affordable alternative to CMA. A total of 1363 patients with unexplained neurodevelopmental delay/intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies were enrolled. Those patients were referred from 15 nonprofit organizations and university centers located in different states in Brazil. The analysis of LP-WGS at 1x coverage (>50kb) revealed a positive testing result in 22% of the cases (304/1363), in which 219 and 85 correspond to pathogenic/likely pathogenic (P/LP) CNVs and variants of uncertain significance (VUS), respectively. The 16% (219/1363) diagnostic yield observed in our cohort is comparable to the 15%-20% reported for CMA in the literature. The use of commercial software, as demonstrated in this study, simplifies the implementation of the test in clinical settings. Particularly for countries like Brazil, where the cost of CMA presents a substantial barrier to most of the population, LP-WGS emerges as a cost-effective alternative for investigating copy number changes in cytogenetics.
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22q11.2 deletion syndrome (22q11.2DS) is a microdeletion syndrome with a broad and heterogeneous phenotype, even though most of the deletions present similar sizes, involving â¼3 Mb of DNA. In a relatively large population of a Brazilian 22q11.2DS cohort (60 patients), we investigated genetic variants that could act as genetic modifiers and contribute to the phenotypic heterogeneity, using a targeted NGS (Next Generation Sequencing) with a specific Ion AmpliSeq panel to sequence nine candidate genes (CRKL, MAPK1, HIRA, TANGO2, PI4KA, HDAC1, ZDHHC8, ZFPM2, and JAM3), mapped in and outside the 22q11.2 hemizygous deleted region. In silico prediction was performed, and the whole-genome sequencing annotation analysis package (WGSA) was used to predict the possible pathogenic effect of single nucleotide variants (SNVs). For the in silico prediction of the indels, we used the genomic variants filtered by a deep learning model in NGS (GARFIELD-NGS). We identified six variants, 4 SNVs and 2 indels, in MAPK1, JAM3, and ZFPM2 genes with possibly synergistic deleterious effects in the context of the 22q11.2 deletion. Our results provide the opportunity for the discovery of the co-occurrence of genetic variants with 22q11.2 deletions, which may influence the patients´ phenotype.
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Síndrome de DiGeorge , Humanos , Síndrome de DiGeorge/genética , Fenotipo , Brasil , Deleción CromosómicaRESUMEN
22q11.2 deletion syndrome (22q11.2DS) shows significant clinical heterogeneity. This study aimed to explore the association between clinical heterogeneity in 22q11.2DS and the parental origin of the deletion. The parental origin of the deletion was determined for 61 individuals with 22q11.2DS by genotyping DNA microsatellite markers and single-nucleotide polymorphisms (SNPs). Among the 61 individuals, 29 (47.5%) had a maternal origin of the deletion, and 32 (52.5%) a paternal origin. Comparison of the frequency of the main clinical features between individuals with deletions of maternal or paternal origin showed no statistically significant difference. However, Truncus arteriosus, pulmonary atresia, seizures, and scoliosis were only found in patients with deletions of maternal origin. Also, a slight difference in the frequency of other clinical features between groups of maternal or paternal origin was noted, including congenital heart disease, endocrinological alterations, and genitourinary abnormalities, all of them more common in patients with deletions of maternal origin. Although parental origin of the deletion does not seem to contribute to the phenotypic variability of most clinical signs observed in 22q11.2DS, these findings suggest that patients with deletions of maternal origin could have a more severe phenotype. Further studies with larger samples focusing on these specific features could corroborate these findings.
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Síndrome de DiGeorge , Humanos , Femenino , Síndrome de DiGeorge/genética , Masculino , Niño , Adolescente , Polimorfismo de Nucleótido Simple , Fenotipo , Preescolar , Adulto , Cromosomas Humanos Par 22/genética , Lactante , Adulto JovenRESUMEN
Retinitis pigmentosa is a group of genetically determined retinal dystrophies characterized by primary photoreceptor apoptosis and can occur in isolated or syndromic conditions. This study reviewed the clinical data of 15 patients with syndromic retinitis pigmentosa from a Rare Disease Reference Center in Brazil and the results of their next-generation sequencing tests. Five males and ten females participated, with the mean ages for ocular disease onset, fundoscopic diagnosis, and molecular evaluation being 9, 19, and 29 years, respectively. Bardet-Biedl syndrome (n = 5) and Usher syndrome (n = 3) were the most frequent diagnoses, followed by other rare conditions. Among the patients, fourteen completed molecular studies, with three negative results and eleven revealing findings in known genes, including novel variants in MKKS (c.432_435del, p.Phe144Leufs*14), USH2A (c.(7301+1_7302-1)_(9369+1_9370-1)del), and CEP250 (c.5383dup, p.Glu1795Glyfs*13, and c.5050del, p.Asp1684Thrfs*9). Except for Kearn-Sayre, all presented an autosomal recessive inheritance pattern with 64% homozygosity results. The long gap between symptom onset and diagnosis highlights the diagnostic challenges faced by the patients. This study reaffirms the clinical heterogeneity of syndromic retinitis pigmentosa and underscores the pivotal role of molecular analysis in advancing our understanding of these diseases.
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Retinitis Pigmentosa , Humanos , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/patología , Retinitis Pigmentosa/diagnóstico , Masculino , Femenino , Adulto , Adolescente , Niño , Adulto Joven , Síndromes de Usher/genética , Síndromes de Usher/patología , Síndromes de Usher/diagnóstico , Brasil/epidemiología , Persona de Mediana Edad , Secuenciación de Nucleótidos de Alto Rendimiento , Síndrome de Bardet-Biedl/genética , MutaciónRESUMEN
The condition known as 22q11.2 deletion syndrome (MIM #188400) is a rare disease with a highly variable clinical presentation including more than 180 features; specific guidelines for screening individuals have been used to support clinical suspicion before confirmatory tests by Brazil's Craniofacial Project. Of the 2568 patients listed in the Brazilian Database on Craniofacial Anomalies, 43 individuals negative for the 22q11.2 deletion syndrome were further investigated through whole-exome sequencing. Three patients (6.7%) presented with heterozygous pathogenic variants in the KMT2A gene, including a novel variant (c.6158+1del) and two that had been previously reported (c.173dup and c.3241C>T); reverse phenotyping concluded that all three patients presented features of Wiedemann-Steiner syndrome, such as neurodevelopmental disorders and dysmorphic facial features (n = 3), hyperactivity and anxiety (n = 2), thick eyebrows and lower-limb hypertrichosis (n = 2), congenital heart disease (n = 1), short stature (n = 1), and velopharyngeal insufficiency (n = 2). Overlapping features between 22q11.2 deletion syndrome and Wiedemann-Steiner syndrome comprised neuropsychiatric disorders and dysmorphic characteristics involving the eyes and nose region; velopharyngeal insufficiency was seen in two patients and is an unreported finding in WDSTS. Therefore, we suggest that both conditions should be included in each other's differential diagnoses.
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Anomalías Múltiples , Contractura , Síndrome de DiGeorge , Facies , Trastornos del Crecimiento , Discapacidad Intelectual , Microcefalia , Insuficiencia Velofaríngea , Humanos , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Anomalías Múltiples/patología , Síndrome de DiGeorge/genética , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/genéticaRESUMEN
Characterization of specific birth defects is essential for conducting scientific investigations, care and therapeutic strategies. This article describes demographic, clinical and genetic aspects, risk factors and access to treatment of Brazilian patients with orofacial clefts registered in a specialized collaborative center of the Brazilian Database on Craniofacial Anomalies (BDCA). We interviewed 70 individuals with typical orofacial clefts using a standard instrument from the database and subjected them to genetic testing. The patients were grouped as syndromic and non-syndromic. The majority of individuals were of lower middle class, native ancestry and syndromic. There was a significant difference in the type of clefts regarding gender. There was no significant difference between bilateral and unilateral, between the side affected, right and left, or familial recurrence related to type of oral cleft. The risk factor familial recurrence was significantly higher among non-syndromic cases. Etiological factors were identified or suggested in 62.5% of the syndromic cases. There was a delay in diagnosis and in access to treatment in most cases. We concluded that gender, native ancestry and low family income represent risk factors. Furthermore, the distribution by cleft types and gender is similar to previous studies. The results can guide scientific investigations and care policies.
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This study describes genomic findings among individuals with both orofacial clefts (OC) and microphthalmia/anophthalmia/coloboma (MAC) recorded in the Brazilian Database on Craniofacial Anomalies (BDCA). Chromosomal microarray analysis (CMA) and Whole Exome Sequencing (WES) were performed in 17 individuals with OC-MAC. Clinical interpretation of molecular findings was based on data available at the BDCA and on re-examination. No copy number variants (CNVs) classified as likely pathogenic or pathogenic were detected by CMA. WES allowed a conclusive diagnosis in six individuals (35.29%), two of them with variants in the CHD7 gene, and the others with variants in the TFAP2A, POMT1, PTPN11, and TP63 genes with the following syndromes: CHARGE, CHD7-spectrum, Branchiooculofacial, POMT1-spectrum, LEOPARD, and ADULT. Variants of uncertain significance (VUS) possibly associated to the phenotypes were found in six other individuals. Among the individuals with VUSes, three individuals presented variants in genes associated to defects of cilia structure and/or function, including DYNC2H1, KIAA0586, WDR34, INTU, RPGRIP1L, KIF7, and LMNA. These results show that WES was the most effective molecular approach for OC-MAC in this cohort. This study also reinforces the genetic heterogeneity of OC-MAC, and the importance of genes related to ciliopathies in this phenotype.
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SATB2-associated syndrome (SAS) is a rare condition, and it is characterized by severe developmental delay/intellectual disability, especially severe speech delay/or absence, craniofacial abnormalities, and behavioral problems. Most of the published reports are limited to children, with little information about the natural history of the disease and the possible novel signs and symptoms or behavioral changes in adulthood. We describe the management and follow-up of a 25-year-old male with SAS due to a de novo heterozygous nonsense variant SATB2:c.715C>T:p.(Arg239*) identified by whole-exome sequencing and review the literature. The case herein described contributes to a better characterization of the natural history of this genetic condition and in addition to the genotype-phenotype correlation of the SATB2:c.715C>T:p.(Arg239*) variant in SAS, highlights some particularities of its management.
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Discapacidad Intelectual , Proteínas de Unión a la Región de Fijación a la Matriz , Masculino , Humanos , Fenotipo , Proteínas de Unión a la Región de Fijación a la Matriz/genética , Síndrome , Estudios de Asociación Genética , Discapacidad Intelectual/genética , Factores de Transcripción/genéticaRESUMEN
Insertions are rare balanced chromosomal rearrangements with an increased risk of imbalances for the offspring. Moreover, balanced rearrangements in individuals with abnormal phenotypes may be associated to the phenotype by different mechanisms. This study describes a three-generation family with a rare chromosomal insertion. G-banded karyotype, chromosomal microarray analysis (CMA), whole-exome sequencing (WES), and low-pass whole-genome sequencing (WGS) were performed. Six individuals had the balanced insertion [ins(9;15)(q33;q21.1q22.31)] and three individuals had the derivative chromosome 9 [der(9)ins(9;15)(q33;q21.1q22.31)]. The three subjects with unbalanced rearrangement showed similar clinical features, including intellectual disability, short stature, and facial dysmorphisms. CMA of these individuals revealed a duplication of 19.3 Mb at 15q21.1q22.31. A subject with balanced rearrangement presented with microcephaly, severe intellectual disability, absent speech, motor stereotypy, and ataxia. CMA of this patient did not reveal pathogenic copy number variations and low-pass WGS showed a disruption of the RABGAP1 gene at the 9q33 breakpoint. This gene has been recently associated with a recessive disorder, which is not compatible with the mode of inheritance in this patient. WES revealed an 88 bp deletion in the MECP2 gene, consistent with Rett syndrome. This study describes the clinical features associated with the rare 15q21.1-q22.31 duplication and reinforces that searching for other genetic causes is warranted for individuals with inherited balanced chromosomal rearrangements and abnormal phenotypes.
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Discapacidad Intelectual , Humanos , Discapacidad Intelectual/genética , Discapacidad Intelectual/diagnóstico , Variaciones en el Número de Copia de ADN , Aberraciones Cromosómicas , Translocación Genética , Reordenamiento GénicoRESUMEN
The widespread use of whole exome sequencing (WES) resulted in the discovery of multilocus pathogenic variations (MPV), defined as two or more distinct or overlapping Mendelian disorders occurring in a patient, leading to a blended phenotype. In this study, we report on a child with autosomal recessive primary microcephaly-5 (MCPH5) and nephropathic cystinosis. The proband is the first child of consanguineous parents, presenting a complex phenotype including neurodevelopmental delay, microcephaly, growth restriction, significant delay of bone maturation, lissencephaly, and abnormality of neuronal migration, photophobia, and renal tubular acidosis. WES revealed two pathogenic and homozygous variants: a c.4174C>T variant in the ASPM gene and a c.382C>T variant in the CTNS gene, explaining the complex phenotype. The literature review showed that most of the patients harboring two variants in recessive disease genes are born to consanguineous parents. To the best of our knowledge, the patient herein described is the first one harboring pathogenic variants in both the ASPM and CTNS genes. These findings highlight the importance of searching for MPV in patients with complex phenotypes investigated by genome-wide testing methods, especially for those patients born to consanguineous parents.
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Síndrome de Fanconi , Microcefalia , Malformaciones del Sistema Nervioso , Humanos , Microcefalia/genética , Homocigoto , Proteínas del Tejido Nervioso/genéticaRESUMEN
Biallelic loss-of-function variants in the TBC1D2B gene were recently reported as a cause of a neurodevelopmental disorder with seizures and gingival overgrowth. Here, we report two male siblings with the similar clinical characteristics. They started with gingival overgrowth and bilateral growth of soft tissues in the malar region at 3 years of age, which evolved with significant maxillary hypertrophy and compression of the brainstem due to fibrous dysplasia of facial bones. After disease evolution, they presented with mental deterioration, limb tremors, and gait ataxia. One of them also presented with seizures. Whole exome sequencing revealed a novel biallelic frameshift variant [c.595del; p.(Val199Trpfs*22)] in the TBC1D2B gene in both patients, which was confirmed and found in heterozygous state in each of their parents. There are strong similarities in clinical characteristics, age of onset, and evolution between the patients described here and cases reported in the literature, including cherubism-like phenotype with progressive gingival overgrowth and seizures. This is the fourth family in the world in which a biallelic loss-of-function variant in the TBC1D2B gene is associated with this phenotype. These results support that loss of TBC1D2B is the cause of this rare condition.
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Disfunción Cognitiva , Sobrecrecimiento Gingival , Humanos , Masculino , Disfunción Cognitiva/genética , Mutación del Sistema de Lectura , Sobrecrecimiento Gingival/genética , Linaje , Convulsiones/genética , HermanosRESUMEN
Admixture is known to greatly impact the genetic landscape of a population and, while genetic variation underlying human phenotypes has been shown to differ among populations, studies on admixed subjects are still scarce. Latin American populations are the result of complex demographic history, such as 2 or 3-way admixing events, bottlenecks and/or expansions, and adaptive events unique to the American continent. To explore the impact of these events on the genetic structure of Latino populations, we evaluated the following haplotype features: linkage disequilibrium, shared identity by descent segments, runs of homozygosity, and extended haplotype homozygosity (integrated haplotype score) in Latinos represented in the 1000 Genome Project along with array data from 171 Brazilians sampled in the South and Southeast regions of Brazil. We found that linkage disequilibrium decay relates to the amount of American and African ancestry. The extent of identity by descent sharing positively correlates with historical effective population sizes, which we found to be steady or growing, except for Puerto Ricans and Colombians. Long runs of homozygosity, a particular instance of autozygosity, was only enriched in Peruvians and Native Americans. We used simulations to account for random sampling and linkage disequilibrium to filter positive selection indexes and found 244 unique markers under selection, 26 of which are common to 2 or more populations. Some markers exhibiting positive selection signals had estimated time to the most recent common ancestor consistent with human adaptation to the American continent. In conclusion, Latino populations present highly divergent haplotype characteristics that impact genetic architecture and underlie complex phenotypes.
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Genética de Población , Hispánicos o Latinos , Brasil , Demografía , Haplotipos , Hispánicos o Latinos/genética , Humanos , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido SimpleRESUMEN
Runs of homozygosity (ROH) in the human genome may be clinically relevant. The aim of this study was to report the frequency of increased ROH of the autosomal genome in individuals with neurodevelopmental delay/intellectual disability and/or multiple congenital anomalies, and to compare these data with a control group. Data consisted of calls of homozygosity from 265 patients and 289 controls. In total, 7.2% (19/265) of the patients showed multiple ROH exceeding 1% of autosomal genome, compared to 1.4% (4/289) in the control group (p=0.0006). Homozygosity ranged from 1.38% to 22.12% among patients, and from 1.53 to 2.40% in the control group. In turn, 1.9% (5/265) of patients presented ROH ≥10Mb in a single chromosome, compared to 0.3% (1/289) of individuals from the control group (p=0.0801). By excluding cases with reported consanguineous parents (15/24), the frequency of increased ROH was 3.4% (9/250) among patients and 1.7% (5/289) in the control group, considering multiple ROH exceeding 1% of the autosome genome and ROH ≥10Mb in a single chromosome together, although not statistically significant (p=0.1873). These results reinforce the importance of investigating ROH, which with complementary diagnostic tests can improve the diagnostic yield for patients with such conditions.
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BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) is a rare disease with an important characteristic-clinical heterogeneity. The diversity of organs, regions, and systems of the body that can be affected requires periodic updating of health professionals so that they can recognize these clinical signs as belonging to 22q11.2DS. Updated professionals are equally important for the appropriate and timely clinical management of individuals with a positive diagnosis. In this context, this article aimed to map and analyze the access to healthcare for individuals with 22q11.2DS until the moment of diagnosis. RESULTS: We analyzed the clinical data of 111 individuals with 22q11.2DS registered in the Brazilian Database on Craniofacial Anomalies (BDCA) from 2008 to 2020. In this study, individuals were diagnosed at a median age of 9 years (mean = 9.7 years). Before the genetic investigation, they accessed 68.75% of the internationally recommended evaluations available at BDCA. Recurrent 22q11.2DS clinical manifestations such as delayed neuropsychomotor development, lip and/or palate defects, cardiac malformation and/or hematological/immunological alteration co-occurred in at least 72.06% of individuals. Cardiac malformation was the only clinical alteration that lowered the median diagnostic age, corresponding to 6.5 years of age with a cardiac malformation versus 11 years of age without one (p = 0.0006). CONCLUSIONS: In Brazil, 22q11.2 DS is under-recognized, and early diagnosis and management of affected individuals are still a distant reality. In this sense, 22q11.2 DS suspicion followed by the elimination of obstacles for its diagnosis confirmation is essential to increase life expectancy and improve the quality of life of these individuals in Brazil.
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Síndrome de DiGeorge , Cardiopatías Congénitas , Brasil , Niño , Síndrome de DiGeorge/diagnóstico , Síndrome de DiGeorge/genética , Cardiopatías Congénitas/genética , Humanos , Calidad de VidaRESUMEN
A region of 160 kb at Xp21.2 has been defined as dosage-sensitive sex reversal (DSS) and includes the NR0B1 gene, considered to be the candidate gene involved in XY gonadal dysgenesis if overexpressed. We describe a girl with 46,XY partial gonadal dysgenesis carrying a 297 kb duplication at Xp21.2 upstream of NR0B1 initially detected by chromosomal microarray analysis. Fine mapping of the breakpoints by whole-genome sequencing showed a tandem duplication of TASL (CXorf21), GK and partially TAB3, upstream of NR0B1. This is the first description of an Xp21.2 duplication upstream of NR0B1 associated with 46,XY partial gonadal dysgenesis.
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Disgenesia Gonadal 46 XY , Femenino , Humanos , Receptor Nuclear Huérfano DAX-1/genética , Disgenesia Gonadal 46 XY/genéticaRESUMEN
Abstract Objective This article presents a clinical and cytogenomic approach that focuses on the diagnosis of syndromic oral clefts (OCs). Methods The inclusion criteria were individuals with OC presenting four or more minor signs and no major defects (non-syndromic oral clefts [NSOCs]) as well as individuals with OC presenting at least another major defect, regardless of the number of minor signs (syndromic oral clefts [SOCs]). The exclusion criteria included NSOC with less than four minor signs, SOC with known etiology, as well as atypical oral clefts. Results Of 1647 individuals with OC recorded in the Brazilian Database of Craniofacial Anomalies, 100 individuals were selected for chromosome microarray analysis (CMA). Among these, 44 individuals were clinically classified as NSOC and 56 as SOC. CMA was performed for both groups, and abnormal CMA was identified in 9%, all previously classified as SCO. The clinical and CMA data analyses showed a significant predominance of abnormal CMA in individuals classified as SOC (p = 0.0044); prematurity, weight, length, and head circumference at birth were significantly lower in the group with abnormal CMA. Besides, minor signs were significantly higher in this group (p = 0.0090). Conclusion The rigorous selection of cases indicates that the significant variables could help in early recognition of SOC. This study reinforces the importance of applying the CMA technique to establish the diagnosis of SOC. This is an important and universal issue in clinical practice for intervention, care, and genetic counseling.
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Humanos , Labio Leporino/genética , Fisura del Paladar/genética , Brasil , Aberraciones Cromosómicas , GenómicaRESUMEN
OBJECTIVE: This article presents a clinical and cytogenomic approach that focuses on the diagnosis of syndromic oral clefts (OCs). METHODS: The inclusion criteria were individuals with OC presenting four or more minor signs and no major defects (non-syndromic oral clefts [NSOCs]) as well as individuals with OC presenting at least another major defect, regardless of the number of minor signs (syndromic oral clefts [SOCs]). The exclusion criteria included NSOC with less than four minor signs, SOC with known etiology, as well as atypical oral clefts. RESULTS: Of 1647 individuals with OC recorded in the Brazilian Database of Craniofacial Anomalies, 100 individuals were selected for chromosome microarray analysis (CMA). Among these, 44 individuals were clinically classified as NSOC and 56 as SOC. CMA was performed for both groups, and abnormal CMA was identified in 9%, all previously classified as SCO. The clinical and CMA data analyses showed a significant predominance of abnormal CMA in individuals classified as SOC (pâ¯=â¯0.0044); prematurity, weight, length, and head circumference at birth were significantly lower in the group with abnormal CMA. Besides, minor signs were significantly higher in this group (pâ¯=â¯0.0090). CONCLUSION: The rigorous selection of cases indicates that the significant variables could help in early recognition of SOC. This study reinforces the importance of applying the CMA technique to establish the diagnosis of SOC. This is an important and universal issue in clinical practice for intervention, care, and genetic counseling.
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Labio Leporino , Fisura del Paladar , Brasil , Aberraciones Cromosómicas , Labio Leporino/genética , Fisura del Paladar/genética , Genómica , Humanos , Recién NacidoRESUMEN
Abstract Introduction: Non-syndromic orofacial clefts have a complex etiology due to the contribution from both genetic and environmental risk factors, as well as the interaction between them. Among the more than 15 susceptibility loci for non-syndromic orofacial clefts with considerable statistical and biological support, the IRF6 is the most validated gene by the majority of studies. Nonetheless, in genetically heterogeneous populations such as Brazilian, the confirmation of association between non-syndromic orofacial clefts and IRF6 common variants is not a consolidated fact and unrecognized IRF6 variants are poorly investigated. Objective: The aim of this study was to investigate the association of IRF6 polymorphisms with non-syndromic orofacial clefts development in a population from northeast Brazil. Methods: Blood samples of 186 non-syndromic orofacial clefts patients and 182 controls from Rio Grande do Norte, Brazil, were obtained to analyze IRF6 polymorphisms (rs2235371, rs642961, rs2236907, rs861019, and rs1044516) by real-time polymerase chain reaction. Non-syndromic orofacial clefts patients were classified in cleft lip and palate, cleft palate only and cleft lip only groups. Results: The genotype and allele frequencies of single nucleotide polymorphism rs2235371 in IRF6 showed significant differences in patients with cleft palate when compared to the controls, whereas no association was shown between rs642961, rs2236907, rs861019, and rs1044516 and non-syndromic orofacial clefts. Conclusion: The association found between rs2235371 and isolated cleft palate should be interpreted with caution due to the low number of individuals investigated, and more studies with larger sample size are needed to confirm these association. In addition, there is a lack of association of the rs642961, rs2236907 and rs861019 polymorphisms with non-syndromic orofacial clefts susceptibility.
Resumo Introdução: As fendas orofaciais não sindrômicas possuem uma etiologia complexa devido à contribuição de fatores de risco genéticos e ambientais, assim como a interação entre eles. Dentre os mais de 15loci de susceptibilidade para as fendas orofaciais não sindrômicas com considerável suporte estatístico e biológico, o IRF6 é o gene mais validado pela maioria dos estudos. Apesar disso, em populações geneticamente heterogêneas como a brasileira, a confirmação da associação entre as fendas orofaciais não sindrômicas e as variantes mais comuns do IRF6 ainda não é um fato consolidado e outras variantes não tão conhecidas IRF6 são pouco investigadas. Objetivo: O objetivo deste estudo foi investigar a associação de variados polimorfismos do IRF6 com o desenvolvimento das fendas orofaciais não sindrômicas em uma população do nordeste do Brasil. Método: Amostras de sangue de 186 pacientes com fendas orofaciais não sindrômicas e 182 controles do estado do Rio Grande do Norte, Brasil, foram obtidas para analisar os polimorfismos do IRF6 (rs2235371, rs642961, rs2236907, rs861019 e rs1044516) por reação em cadeia da polimerase em tempo real. Os pacientes com fendas orofaciais não sindrômicas foram classificados em fenda labiopalatina, fenda palatina isolada e fenda labial isolada. Resultados: As frequências genotípica e alélica do polimorfismo de único nucleotídeo rs2235371 no IRF6 mostraram-se significativamente diferentes em pacientes com fenda palatina isolada quando comparadas às dos controles, enquanto que nenhuma associação foi encontrada entre rs642961, rs2236907, rs861019 e rs1044516 e risco para o desenvolvimento das fendas orofaciais não sindrômicas. Conclusão: A associação encontrada entre rs2235371 e fenda palatina isolada deve ser interpretada com cautela devido ao baixo número de indivíduos investigados, sendo necessários mais estudos com um tamanho amostral maior para confirmar essa associação. Além disso, não foram encontradas associações significativas entre os demais polimorfismos do IRF6 rs642961, rs2236907, rs861019 e rs1044516 e a susceptibilidade às fendas orofaciais não sindrômicas.