RESUMO
Nonsyndromic orofacial clefts (NSOFCs) represent a large proportion (70%-80%) of all OFCs. They can be broadly categorized into nonsyndromic cleft lip with or without cleft palate (NSCL/P) and nonsyndromic cleft palate only (NSCPO). Although NSCL/P and NSCPO are considered etiologically distinct, recent evidence suggests the presence of shared genetic risks. Thus, we investigated the genetic overlap between NSCL/P and NSCPO using African genome-wide association study (GWAS) data on NSOFCs. These data consist of 814 NSCL/P, 205 NSCPO cases, and 2159 unrelated controls.â¯We generated common single-nucleotide variants (SNVs) association summary statistics separately for each phenotype (NSCL/P and NSCPO) under an additive genetic model. Subsequently, we employed the pleiotropic analysis under the composite null (PLACO) method to test for genetic overlap. Our analysis identified two loci with genome-wide significance (rs181737795 [p = 2.58E-08] and rs2221169 [p = 4.5E-08]) and one locus with marginal significance (rs187523265 [p = 5.22E-08]). Using mouse transcriptomics data and information from genetic phenotype databases, we identified MDN1, MAP3k7, KMT2A, ARCN1, and VADC2 as top candidate genes for the associated SNVs. These findings enhance our understanding of genetic variants associated with NSOFCs and identify potential candidate genes for further exploration.
Assuntos
Fenda Labial , Fissura Palatina , Feminino , Humanos , Masculino , Camundongos , População Negra/genética , Estudos de Casos e Controles , Fenda Labial/genética , Fissura Palatina/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Fenótipo , Polimorfismo de Nucleotídeo Único , AnimaisRESUMO
BACKGROUND: A fundamental ethical issue in African genomics research is how socio-cultural factors impact perspectives, acceptance, and utility of genomic information, especially in stigmatizing conditions like orofacial clefts (OFCs). Previous research has shown that gatekeepers (e.g., religious, political, family or community leaders) wield considerable influence on the decision-making capabilities of their members, including health issues. Thus, their perspectives can inform the design of engagement strategies and increase exposure to the benefits of genomics testing/research. This is especially important for Africans underrepresented in genomic research. Our study aims to investigate the perspectives of gatekeepers concerning genomic risk information (GRI) in the presence of OFCs in a sub-Saharan African cohort. METHODS: Twenty-five focus group discussions (FGDs) consisting of 214 gatekeepers (religious, community, ethnic leaders, and traditional birth attendants) in Lagos, Nigeria, explored the opinions of participants on genomic risk information (GRI), OFC experience, and the possibility of involvement in collaborative decision-making in Lagos, Nigeria. Transcripts generated from audio recordings were coded and analyzed in NVivo using thematic analysis. RESULTS: Three main themes-knowledge, beliefs, and willingness to act-emerged from exploring the perspective of gatekeepers about GRI in this group. We observed mixed opinions regarding the acceptance of GRI. Many participants believed their role is to guide and support members when they receive results; this is based on the level of trust their members have in them. However, participants felt they would need to be trained by medical experts to do this. Also, religious and cultural beliefs were crucial to determining participants' understanding of OFCs and the acceptance and utilization of GRI. CONCLUSIONS: Incorporating cultural sensitivity into public engagement could help develop appropriate strategies to manage conflicting ideologies surrounding genomic information in African communities. This will allow for more widespread access to the advances in genomics research in underrepresented populations. We also recommend a synergistic relationship between community health specialists/scientists, and community leaders, including spiritual providers to better understand and utilize GRI.
Assuntos
Fenda Labial , Fissura Palatina , Humanos , Nigéria , Grupos Focais , Genômica , Pesquisa QualitativaRESUMO
A consortium of global cleft professionals, predominantly from low- and middle-income countries, identified adaptations to cleft care protocols during and after COVID-19 as a priority learning area of need.A multidisciplinary international working group met on a videoconferencing platform in a multi-staged process to make consensus recommendations for adaptations to cleft protocols within resource-constrained settings. Feedback was sought from a roundtable discussion forum and global organizations involved in comprehensive cleft care.Foundational principles were agreed to enable recommendations to be globally relevant and two areas of focus within the specified topic were identified. First the safety aspects of cleft surgery protocols were scrutinized and COVID-19 adaptations, specifically in the pre- and perioperative periods, were highlighted. Second, surgical procedures and cleft care services were prioritized according to their relationship to functional outcomes and time-sensitivity. The surgical procedures assigned the highest priority were emergent interventions for breathing and nutritional requirements and primary palatoplasty. The cleft care services assigned the highest priority were new-born assessments, pediatric support for children with syndromes, management of acute dental or auditory infections and speech pathology intervention.A collaborative, interdisciplinary and international working group delivered consensus recommendations to assist with the provision of cleft care in low- and middle-income countries. At a time of global cleft care delays due to COVID-19, a united approach amongst global cleft care providers will be advantageous to advocate for children born with cleft lip and palate in resource-constrained settings.
Assuntos
COVID-19 , Fenda Labial , Fissura Palatina , Criança , Humanos , Fissura Palatina/cirurgia , Fenda Labial/cirurgia , Países em DesenvolvimentoRESUMO
SPECC1L mutations have been identified in patients with rare atypical orofacial clefts and with syndromic cleft lip and/or palate (CL/P). These mutations cluster in the second coiled-coil and calponin homology domains of SPECC1L and severely affect the ability of SPECC1L to associate with microtubules. We previously showed that gene-trap knockout of Specc1l in mouse results in early embryonic lethality. We now present a truncation mutant mouse allele, Specc1lΔC510, that results in perinatal lethality. Specc1lΔC510/ΔC510 homozygotes showed abnormal palate rugae but did not show cleft palate. However, when crossed with a gene-trap allele, Specc1lcGT/ΔC510 compound heterozygotes showed a palate elevation delay with incompletely penetrant cleft palate. Specc1lcGT/ΔC510 embryos exhibit transient oral epithelial adhesions at E13.5, which may delay shelf elevation. Consistent with oral adhesions, we show periderm layer abnormalities, including ectopic apical expression of adherens junction markers, similar to Irf6 hypomorphic mutants and Arhgap29 heterozygotes. Indeed, SPECC1L expression is drastically reduced in Irf6 mutant palatal shelves. Finally, we wanted to determine if SPECC1L deficiency also contributed to non-syndromic (ns) CL/P. We sequenced 62 Caucasian, 89 Filipino, 90 Ethiopian, 90 Nigerian and 95 Japanese patients with nsCL/P and identified three rare coding variants (p.Ala86Thr, p.Met91Iso and p.Arg546Gln) in six individuals. These variants reside outside of SPECC1L coiled-coil domains and result in milder functional defects than variants associated with syndromic clefting. Together, our data indicate that palate elevation is sensitive to deficiency of SPECC1L dosage and function and that SPECC1L cytoskeletal protein functions downstream of IRF6 in palatogenesis.
Assuntos
Fissura Palatina/patologia , Fatores Reguladores de Interferon/metabolismo , Mutação , Fosfoproteínas/fisiologia , Animais , Fissura Palatina/genética , Fissura Palatina/metabolismo , Feminino , Humanos , Fatores Reguladores de Interferon/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfoproteínas/genética , Fosfoproteínas/metabolismoRESUMO
OBJECTIVES: Cleft lip with/without cleft palate and cleft palate only is congenital birth defects where the upper lip and/or palate fail to fuse properly during embryonic facial development. Affecting ~1.2/1000 live births worldwide, these orofacial clefts impose significant social and financial burdens on affected individuals and their families. Orofacial clefts have a complex etiology resulting from genetic variants combined with environmental covariates. Recent genome-wide association studies and whole-exome sequencing for orofacial clefts identified significant genetic associations and variants in several genes. Of these, we investigated the role of common/rare variants in SHH, RORA, MRPL53, ACVR1, and GDF11. MATERIALS AND METHODS: We sequenced these five genes in 1255 multi-ethnic cleft lip with/without palate and cleft palate only samples in order to find variants that may provide potential explanations for the missing heritability of orofacial clefts. Rare and novel variants were further analyzed using in silico predictive tools. RESULTS: Ninteen total variants of interest were found, with variant types including stop-gain, missense, synonymous, intronic, and splice-site variants. Of these, 3 novel missense variants were found, one in SHH, one in RORA, and one in GDF11. CONCLUSION: This study provides evidence that variants in SHH, RORA, MRPL53, ACVR1, and GDF11 may contribute to risk of orofacial clefts in various populations.
Assuntos
Fenda Labial , Fissura Palatina , Proteínas Morfogenéticas Ósseas , Fenda Labial/genética , Fissura Palatina/genética , Estudo de Associação Genômica Ampla , Fatores de Diferenciação de Crescimento/genética , HumanosRESUMO
BACKGROUND: Van der Woude syndrome (VWS) is the most common syndromic orofacial cleft which accounts for approximately 2% of all cleft lip (CL) and/or palate cases. It is characterized by the presence of lower lip pits, in addition to CL, CL with or without cleft palate, cleft palate only, and hypodontia. It is inherited as an autosomal-dominant trait with almost complete penetrance but variable expressivity, and different variants in IRF6 gene have been reported in different populations around the world including African populations (Ethiopian, Ghanaian, and Nigerian). METHODS AND FINDINGS: The authors investigated the role of IRF6 in Ethiopian families with VWS. The DNA of 7 families with VWS from Ethiopia were screened by Sanger sequencing. The authors screened all 9 exons of IRF6 and found a novel missense variant in exon 4 (p. Gly65Glu). This variant was predicted to be deleterious/probably damaging by Sift and PolyPhen, respectively. The IRF6 variant (p. Gly65Glu) segregates in the family since it was identified in the father and a sibling. CONCLUSION: Several of the individuals with lower lip pits in this study did not seek treatment. This is due to lack of awareness about the significance of this minor looking deformity and its consequences, and availability of treatment for birth defects. Therefore, it is important to educate families. Finally, screening for novel variants in known genes has a role in counseling and prenatal diagnosis for high-risk families.
Assuntos
Fenda Labial , Fissura Palatina , Anormalidades Múltiplas , Fenda Labial/genética , Fissura Palatina/genética , Cistos , Etiópia , Gana , Humanos , Fatores Reguladores de Interferon/genética , Lábio/anormalidades , Mutação , LinhagemRESUMO
OBJECTIVE: Nonsyndromic cleft lip and/or cleft palate (NSCL/P) have multifactorial etiology where genetic factors, gene-environment interactions, stochastic factors, gene-gene interactions, and parent-of-origin effects (POEs) play cardinal roles. POEs arise when the parental origin of alleles differentially impacts the phenotype of the offspring. The aim of this study was to identify POEs that can increase risk for NSCL/P in humans using a genome-wide dataset. METHODS: The samples (174 case-parent trios from Ghana, Ethiopia, and Nigeria) included in this study were from the African only genome wide association studies (GWAS) that was published in 2019. Genotyping of individual DNA using over 2 million multiethnic and African ancestry-specific single-nucleotide polymorphisms from the Illumina Multi-Ethnic Genotyping Array v2 15070954 A2 (genome build GRCh37/hg19) was done at the Center for Inherited Diseases Research. After quality control checks, PLINK was employed to carry out POE analysis employing the pooled subphenotypes of NSCL/P. RESULTS: We observed possible hints of POEs at a cluster of genes at a 1 mega base pair window at the major histocompatibility complex class 1 locus on chromosome 6, as well as at other loci encompassing candidate genes such as ASB18, ANKEF1, AGAP1, GABRD, HHAT, CCT7, DNMT3A, EPHA7, FOXO3, lncRNAs, microRNA, antisense RNAs, ZNRD1, ZFAT, and ZBTB16. CONCLUSION: Findings from our study suggest that some loci may increase the risk for NSCL/P through POEs. Additional studies are required to confirm these suggestive loci in NSCL/P etiology.
Assuntos
Fenda Labial , Fissura Palatina , África Subsaariana , Fenda Labial/genética , Fissura Palatina/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Novel or rare damaging mutations have been implicated in the developmental pathogenesis of nonsyndromic cleft lip with or without cleft palate (nsCL ± P). Thus, we investigated the human genome for high-impact mutations that could explain the risk of nsCL ± P in our cohorts.We conducted next-generation sequencing (NGS) analysis of 130 nsCL ± P case-parent African trios to identify pathogenic variants that contribute to the risk of clefting. We replicated this analysis using whole-exome sequence data from a Brazilian nsCL ± P cohort. Computational analyses were then used to predict the mechanism by which these variants could result in increased risks for nsCL ± P.We discovered damaging mutations within the AFDN gene, a cell adhesion molecule (CAMs) that was previously shown to contribute to cleft palate in mice. These mutations include p.Met1164Ile, p.Thr453Asn, p.Pro1638Ala, p.Arg669Gln, p.Ala1717Val, and p.Arg1596His. We also discovered a novel splicing p.Leu1588Leu mutation in this protein. Computational analysis suggests that these amino acid changes affect the interactions with other cleft-associated genes including nectins (PVRL1, PVRL2, PVRL3, and PVRL4) CDH1, CTNNA1, and CTNND1.This is the first report on the contribution of AFDN to the risk for nsCL ± P in humans. AFDN encodes AFADIN, an important CAM that forms calcium-independent complexes with nectins 1 and 4 (encoded by the genes PVRL1 and PVRL4). This discovery shows the power of NGS analysis of multiethnic cleft samples in combination with a computational approach in the understanding of the pathogenesis of nsCL ± P.
RESUMO
In this study, we investigated the role of the transcription factor Six2 in palate development. Six2 was selected using the SysFACE tool to predict genes from the 2p21 locus, a region associated with clefting in humans by GWAS, that are likely to be involved in palatogenesis. We functionally validated the predicted role of Six2 in palatogenesis by showing that 22% of Six2 null embryos develop cleft palate. Six2 contributes to palatogenesis by promoting mesenchymal cell proliferation and regulating bone formation. The clefting phenotype in Six2-/- embryos is similar to Pax9 null embryos, so we examined the functional relationship of these two genes. Mechanistically, SIX2 binds to a PAX9 5' upstream regulatory element and activates PAX9 expression. In addition, we identified a human SIX2 coding variant (p.Gly264Glu) in a proband with cleft palate. We show this missense mutation affects the stability of the SIX2 protein and leads to decreased PAX9 expression. The low penetrance of clefting in the Six2 null mouse combined with the mutation in one patient with cleft palate underscores the potential combinatorial interactions of other genes in clefting. Our study demonstrates that Six2 interacts with the developmental gene regulatory network in the developing palate.
Assuntos
Proteínas de Homeodomínio/metabolismo , Fator de Transcrição PAX9/genética , Fatores de Transcrição/metabolismo , Animais , Fissura Palatina/embriologia , Fissura Palatina/genética , Anormalidades Craniofaciais/embriologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Genes Homeobox , Proteínas de Homeodomínio/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Morfogênese , Proteínas do Tecido Nervoso/metabolismo , Osteogênese , Fator de Transcrição PAX9/metabolismo , Fatores de Transcrição Box Pareados , Palato/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genéticaRESUMO
Orofacial clefts are common developmental disorders that pose significant clinical, economical and psychological problems. We conducted genome-wide association analyses for cleft palate only (CPO) and cleft lip with or without palate (CL/P) with ~17 million markers in sub-Saharan Africans. After replication and combined analyses, we identified novel loci for CPO at or near genome-wide significance on chromosomes 2 (near CTNNA2) and 19 (near SULT2A1). In situ hybridization of Sult2a1 in mice showed expression of SULT2A1 in mesenchymal cells in palate, palatal rugae and palatal epithelium in the fused palate. The previously reported 8q24 was the most significant locus for CL/P in our study, and we replicated several previously reported loci including PAX7 and VAX1.
Assuntos
População Negra/genética , Fissura Palatina/genética , Genética Populacional , Genoma Humano , Genômica , Locos de Características Quantitativas , Alelos , Animais , Mapeamento Cromossômico , Modelos Animais de Doenças , Elementos Facilitadores Genéticos , Feminino , Expressão Gênica , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genômica/métodos , Genótipo , Humanos , Masculino , Camundongos , Razão de Chances , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: Nonsyndromic orofacial clefts (NSOFCs) represent the most common congenital anomalies in the head and neck region. Multiple factors contribute to the occurrence of this anomaly. The etiology of NSOFCs in the Ethiopian population has not been investigated prior to this study. AIMS OF THE STUDY: To assess the role of maternal environmental factors in the occurrence of NSOFCs in the Ethiopian Population. METHODS: The authors used unmatched case control study design and evaluated the role of environmental factors to the occurrence of NSOFCs in the Ethiopian population. The participants were recruited from the same institution (Yekatit 12 Hospital Medical College). The authors studied 760 mothers (359 mothers of children born with NSOFCs and 401 mothers of children born without any congenital anomalies). Univariate and multivariate logistic regression analyses were used to calculate relative risk by odds ratio and 95% confidence interval. RESULTS: Mothers who gave history of bronchial asthma and mothers who were admitted for threatened abortion had a higher risk of delivering a child with NSOFCS P value=0.013; AOR=0.194, 95% CI [0.053-0.712], P value <0.001; AOR= 0.179, 95% CI [0.091-0.352] respectively. Higher number of children with NSOFCs were born to mothers who were exposed to diagnostic X-ray investigation during early pregnancy than those who were not exposed P value 0.048; AOR=0.375, 95% CI [0.142-0.990]. CONCLUSION: Maternal exposure to diagnostic x-ray, maternal chronic illness like bronchial asthma and threatened abortion were found to be associated with the occurrence of NSOFCS in the studied population.
Assuntos
Encéfalo/anormalidades , Fenda Labial/etiologia , Fissura Palatina/etiologia , Estudos de Casos e Controles , Pré-Escolar , Feminino , Humanos , Lactente , Exposição Materna , Mães , Gravidez , Fatores de RiscoRESUMO
Cleft palate (CP) is a common birth defect occurring in 1 in 2,500 live births. Approximately half of infants with CP have a syndromic form, exhibiting other physical and cognitive disabilities. The other half have nonsyndromic CP, and to date, few genes associated with risk for nonsyndromic CP have been characterized. To identify such risk factors, we performed a genome-wide association study of this disorder. We discovered a genome-wide significant association with a missense variant in GRHL3 (p.Thr454Met [c.1361C>T]; rs41268753; p = 4.08 × 10(-9)) and replicated the result in an independent sample of case and control subjects. In both the discovery and replication samples, rs41268753 conferred increased risk for CP (OR = 8.3, 95% CI 4.1-16.8; OR = 2.16, 95% CI 1.43-3.27, respectively). In luciferase transactivation assays, p.Thr454Met had about one-third of the activity of wild-type GRHL3, and in zebrafish embryos, perturbed periderm development. We conclude that this mutation is an etiologic variant for nonsyndromic CP and is one of few functional variants identified to date for nonsyndromic orofacial clefting. This finding advances our understanding of the genetic basis of craniofacial development and might ultimately lead to improvements in recurrence risk prediction, treatment, and prognosis.
Assuntos
Fissura Palatina/genética , Proteínas de Ligação a DNA/genética , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/genética , Animais , Estudos de Casos e Controles , Fissura Palatina/diagnóstico , Modelos Animais de Doenças , Etnicidade/genética , Loci Gênicos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Mutação de Sentido Incorreto , Fatores de Risco , Peixe-Zebra/embriologia , Peixe-Zebra/genéticaRESUMO
BACKGROUND: Men's involvement in obstetrics care is an important strategy in reducing preventable maternal morbidity and mortality. This is particularly important in developing countries where men often make decision on financial, health and other family issues. Hence, the objective of this study was to assess men's knowledge and involvement in obstetric danger signs; birth preparedness and complication readiness in Burayu town administration, Oromia, Ethiopia. METHODS: A community based cross-sectional study was conducted in Burayu town administration, Oromia Region from May 2016 to July 2016. Multistage with systematic random sampling techniques were employed. Bivariate and multivariate logistic regression analyses were performed using SPSS version 20. P-value less than 0.05 were taken as a cutoff point to declare significant association. RESULT: A total of 523 men were involved in the study. The mean and ± SD age of the study participant was 36.6 ± 7 years. Majority of the participants were Orthodox religion followers and, employees of private organization, regarding residency majority were residing in urban setting. Pregnancy related vaginal bleeding was the most familiar danger sign recognized by the study participants which was 342(65.4%). From the total, 441(84.3%) of men were highly involved in preparation of arranging for postpartum cultural food expenses, 345(66.0%) for clean clothes both for the baby and mother; and 71-76% participants were involved in availing transport money for antenatal, delivery and postnatal care. The study revealed that educational status of men, monthly income, knowledge of pregnancy danger sign, delivery and post-delivery care, and knowledge of birth preparedness and complication readiness (BP/CR) were significantly associated with men's involvement in BP/CR. CONCLUSION: Majority of participants had knowledge on obstetric danger sign. Men showed low interest to donate blood to their wives during antenatal, delivery and postpartum care. There is a need continued awareness creation on danger sings as well as birth preparedness.
Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Homens , Parto , Complicações na Gravidez , Adulto , Estudos Transversais , Edema , Escolaridade , Etiópia , Feminino , Humanos , Renda , Masculino , Mortalidade Materna , Complicações do Trabalho de Parto , Placenta Retida , Cuidado Pós-Natal , Gravidez , Cuidado Pré-Natal , Convulsões , Hemorragia UterinaRESUMO
Non-syndromic (NS) cleft lip with or without cleft palate (CL/P) is a common disorder with a strong genetic underpinning. Genome-wide association studies have detected common variants associated with this disorder, but a large portion of the genetic risk for NSCL/P is conferred by unidentified rare sequence variants. Mutations in IRF6 (Interferon Regulatory Factor 6) and GRHL3 (Grainyhead-like 3) cause Van der Woude syndrome, which includes CL/P. Both genes encode members of a regulatory network governing periderm differentiation in model organisms. Here, we report that Krüppel-like factor 17 (Klf17), like Grhl3, acts downstream of Irf6 in this network in zebrafish periderm. Although Klf17 expression is absent from mammalian oral epithelium, a close homologue, Klf4, is expressed in this tissue and is required for the differentiation of epidermis. Chromosome configuration capture and reporter assays indicated that IRF6 directly regulates an oral-epithelium enhancer of KLF4. To test whether rare missense variants of KLF4 contribute risk for NSCL/P, we sequenced KLF4 in approximately 1000 NSCL/P cases and 300 controls. By one statistical test, missense variants of KLF4 as a group were enriched in cases versus controls. Moreover, two patient-derived KLF4 variants disrupted periderm differentiation upon forced expression in zebrafish embryos, suggesting that they have dominant-negative effect. These results indicate that rare NSCL/P risk variants can be found in members of the gene regulatory network governing periderm differentiation.
Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Fatores Reguladores de Interferon/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Estudos de Casos e Controles , Fenda Labial/metabolismo , Fissura Palatina/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Fatores Reguladores de Interferon/genética , Fator 4 Semelhante a Kruppel , Masculino , Camundongos , Mutação , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/genéticaRESUMO
Orofacial clefts (OFCs), which include non-syndromic cleft lip with or without cleft palate (CL/P), are among the most common birth defects in humans, affecting approximately 1 in 700 newborns. CL/P is phenotypically heterogeneous and has a complex etiology caused by genetic and environmental factors. Previous genome-wide association studies (GWASs) have identified at least 15 risk loci for CL/P. As these loci do not account for all of the genetic variance of CL/P, we hypothesized the existence of additional risk loci. We conducted a multiethnic GWAS in 6480 participants (823 unrelated cases, 1700 unrelated controls and 1319 case-parent trios) with European, Asian, African and Central and South American ancestry. Our GWAS revealed novel associations on 2p24 near FAM49A, a gene of unknown function (P = 4.22 × 10-8), and 19q13 near RHPN2, a gene involved in organizing the actin cytoskeleton (P = 4.17 × 10-8). Other regions reaching genome-wide significance were 1p36 (PAX7), 1p22 (ARHGAP29), 1q32 (IRF6), 8q24 and 17p13 (NTN1), all reported in previous GWASs. Stratification by ancestry group revealed a novel association with a region on 17q23 (P = 2.92 × 10-8) among individuals with European ancestry. This region included several promising candidates including TANC2, an oncogene required for development, and DCAF7, a scaffolding protein required for craniofacial development. In the Central and South American ancestry group, significant associations with loci previously identified in Asian or European ancestry groups reflected their admixed ancestry. In summary, we have identified novel CL/P risk loci and suggest new genes involved in craniofacial development, confirming the highly heterogeneous etiology of OFCs.
Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Povo Asiático/genética , População Negra/genética , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 19/genética , Cromossomos Humanos Par 2/genética , Etnicidade , Feminino , Loci Gênicos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Fatores de Risco , População Branca/genéticaRESUMO
OBJECTIVE: Cleft lip and/or cleft palate (CL/P) are congenital anomalies of the face and have multifactorial etiology, with both environmental and genetic risk factors playing crucial roles. Though at least 40 loci have attained genomewide significant association with nonsyndromic CL/P, these loci largely reside in noncoding regions of the human genome, and subsequent resequencing studies of neighboring candidate genes have revealed only a limited number of etiologic coding variants. The present study was conducted to identify etiologic coding variants in GREM1, a locus that has been shown to be largely associated with cleft of both lip and soft palate. PATIENTS AND METHOD: We resequenced DNA from 397 sub-Saharan Africans with CL/P and 192 controls using Sanger sequencing. Following analyses of the sequence data, we observed 2 novel coding variants in GREM1. These variants were not found in the 192 African controls and have never been previously reported in any public genetic variant database that includes more than 5000 combined African and African American controls or from the CL/P literature. RESULTS: The novel variants include p.Pro164Ser in an individual with soft palate cleft only and p.Gly61Asp in an individual with bilateral cleft lip and palate. The proband with the p.Gly61Asp GREM1 variant is a van der Woude (VWS) case who also has an etiologic variant in IRF6 gene. CONCLUSION: Our study demonstrated that there is low number of etiologic coding variants in GREM1, confirming earlier suggestions that variants in regulatory elements may largely account for the association between this locus and CL/P.
Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , África Subsaariana/epidemiologia , Fenda Labial/epidemiologia , Fissura Palatina/epidemiologia , Feminino , Predisposição Genética para Doença , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Mutação , Linhagem , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND: The prevalence of birth defects including orofacial clefts (OFC) in Ethiopia is not known and there is no established birth defects registration system. OBJECTIVES: To investigate the prevalence and incidence of OFC in Ethiopia. DESIGN: Retrospective hospital-based descriptive study. METHODS: The authors obtained data from the Smile Train database on Ethiopian patients with OFC who underwent surgical treatment from June 2007 to December 2013 at 31 hospitals distributed throughout the country. Data related to live births in Ethiopia during the mentioned period were obtained from the Federal Ministry of Health database for estimates of the incidence and prevalence rates. RESULTS: The total number of life births during the study period was 18,811,316. During this same period, 18,073 cleft patients approximately ranging from 1 to 75 years old were examined and treated at the hospitals mentioned earlier. The incidence rate estimated from the total number of affected children during the study period (N = 8232) is 0.44/1000 live births. The prevalence rate is 0.20/1000 and this was estimated using the number of total population in 2013 (Nâ=â88,703,914). There is a significant difference in frequency between bilateral clefts of the lip and/or palate (CLP) (26.9%) versus unilateral CLP (73.1%) (Pâ<â0.0001). There is also a significant difference in frequency between bilateral cleft lips only (15.4%) versus unilateral cleft lip only (84.6%), Pâ<â0001. CONCLUSION: It is obvious that the findings in this study cannot be representative of the true picture but provides a previously unavailable national estimate of incidence and prevalence of OFC in Ethiopia. It can also be used as comparison for future community-based studies.
Assuntos
Fenda Labial , Fissura Palatina , Adulto , Idoso , Criança , Fenda Labial/diagnóstico , Fenda Labial/epidemiologia , Fissura Palatina/diagnóstico , Fissura Palatina/epidemiologia , Etiópia/epidemiologia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Recém-Nascido , Masculino , Prevalência , Estudos RetrospectivosRESUMO
Nonsyndromic clefts of the lip and palate (NSCLP) are complex genetic traits. Together, they are classified as one of the most common birth defects with a prevalence of 1/700 live births. Genome-wide association studies (GWAS) for nonsyndromic cleft lip with or without cleft palate (NSCL[P]) revealed significant association for common single nucleotide polymorphisms near genes involved in craniofacial development i.e., MAFB, PAX7, VAX1, ARHGAP29 (ABCA4 locus), and IRF6. Sequencing of protein coding regions of the NSCL(P) GWAS candidate genes or adjacent genes suggest a role for rare functional variants. Replication studies in the African population did not observe any significant association with the GWAS candidate genes. On the other hand, the role of rare functional variants in GWAS candidate genes has not been evaluated in the African population. We obtained saliva samples from case triads in Nigeria and Ethiopia for Sanger sequencing of the GWAS candidate genes (MAFB, PAX7, VAX1, ARHGAP29, and IRF6) in order to identify rare functional variants. A total of 220 African samples (140 Nigerians and 80 Ethiopians) were sequenced and we found the following new rare variants- p.His165Asn in the MAFB gene, p.Asp428Asn in the PAX7, a splice-site variant that creates a new donor splice-site in PAX7. We also found three previously reported missense variants p.Gly466Ser in PAX7; p.Leu913Ser and Arg955His in ARHGAP29. No de novo mutations were found. Future genome-wide association and sequencing studies should be conducted using samples from Africa in order to identify new molecular genetic factors that contribute to the etiology of NSCLP.
Assuntos
População Negra/genética , Encéfalo/anormalidades , Fenda Labial/genética , Fissura Palatina/genética , Proteínas Ativadoras de GTPase/genética , Estudo de Associação Genômica Ampla , Humanos , Fator de Transcrição MafB/genética , Fator de Transcrição PAX7/genética , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA/métodosRESUMO
Background: The two most common complications after primary palatoplasty are oronasal fistula and velopharyngeal insufficiency (VPI). To the best of our knowledge, there have been no studies examining postpalatoplasty speech outcomes in Ethiopia. Methods: A hospital-based retrospective cross sectional study design was used. A total of 149 patient records were reviewed, and 103 patients fulfilled all the inclusion criteria. These 103 cleft lip and palate patients who had undergone cleft palate repair at Yekatit 12 Hospital Medical College and who had undergone long-term speech assessment with the speech therapy department from January 2019 to December 2021 were included in this study. The bivariate/multivariate logistic regression was used to compare between different groups of patients, with the level of significance set at a P value of less than 0.05. Results: Moderate and severe hypernasality was seen in 45.7% of patients. Age at time of palatal surgery has significant association with incidence of hypernasality (P = 0.01). The type of cleft, sex of the patient, and type of surgery had no significant association with incidence of hypernasality. Oronasal fistula was seen in 25% of patients, with Pittsburgh type VI being the most common (40%). Conclusions: There is a high rate of VPI and oronasal fistula in this cohort of patients who underwent palatoplasty at Yekatit 12 Hospital. One of the factors for higher complication rate was older age at time of surgery. Therefore, patient education and strengthening the cleft care with training are paramount to ensure better results.
RESUMO
PURPOSE: Ethiopia is the second most populous country in sub-Saharan Africa. While Ethiopia's health care system includes primary health centres, general, and specialised hospitals, allied health care like speech-language pathology was not available until 2003. This article was written with the aim of sharing the experience of establishing speech-language pathology as a profession and the first speech-language pathology training program in Ethiopia. METHOD: In this paper, we retrospectively examine how the leadership of local stakeholders, a multidisciplinary team, and the development of a professional infrastructure led to the success of the program. The authorship group, who were involved in the program from inception to implementation, share their experiences. RESULT: The speech-language pathology undergraduate program at Addis Ababa University graduated its first class in 2019. Plans to grow the training program at the graduate level are ongoing. CONCLUSION: This novel program, grown from several international partnerships, is an example of how low- and middle-income countries can improve access to the service providers necessary to treat their populations.