Project description:<p>The <a href="https://www.commonfund.nih.gov/KidsFirst">Gabriella Miller Kids First Pediatric Research Program</a> (Kids First) is a trans-NIH effort initiated in response to the <a href="https://www.govtrack.us/congress/bills/113/hr2019">2014 Gabriella Miller Kids First Research Act</a> and supported by the NIH Common Fund. This program focuses on gene discovery in pediatric cancers and structural birth defects and the development of the Gabriella Miller Kids First Pediatric Data Resource (Kids First Data Resource). Both childhood cancers and structural birth defects are critical and costly conditions associated with substantial morbidity and mortality. Elucidating the underlying genetic etiology of these diseases has the potential to profoundly improve preventative measures, diagnostics, and therapeutic interventions.</p> <p>WGS and phenotypic data from this study are accessible through dbGaP and <a href="https://kidsfirstdrc.org">kidsfirstdrc.org</a>, where other Kids First datasets can also be accessed.</p> <p>The Kids First study of nonsyndromic orofacial cleft birth defects (OFCs) is a whole genome sequencing study of 415 White parent-case trios drawn from ongoing collaborations led by Dr. Mary L. Marazita of the University of Pittsburgh Center for Craniofacial and Dental Genetics, including collaborations with Dr. George Wehby of the University of Iowa, Dr. Jacqueline Hecht of the University of Texas, and Dr. Terri Beaty of Johns Hopkins University. Sequencing was done by the Washington University McDonell Genome Institute. The case in each of the Kids First trios has cleft lip (CL, Figure A), cleft palate (CP, Figure B), or both (CL+CP, Figure C):</p> <img src="GetImage.cgi?study_id=phs001420&image_name=GMKFCleft.jpg"/> <p>OFCs are genetically complex structural birth defects caused by genetic factors, environmental exposures, and their interactions. OFCs are the most common craniofacial anomalies in humans, affecting approximately 1 in 700 newborns, and are one of the most common structural birth defects worldwide. On average a child with an OFC initially faces feeding difficulties, undergoes 6 surgeries, spends 30 days in hospital, receives 5 years of orthodontic treatment, and participates in ongoing speech therapy, leading to an estimated total lifetime treatment cost of about $200,000. Further, individuals born with an OFC have higher infant mortality, higher mortality rates at all other stages of life, increased incidence of mental health problems, and higher risk for other disorders (notably including breast, brain, and colon cancers). Prior genome-wide linkage and association studies have now identified at least 18 genomic regions likely to contribute to the risk for nonsyndromic OFCs. Despite this substantial progress, the functional/pathogenic variants at OFC-associated regions are mostly still unknown. Because previous OFC genomic studies (genome-wide linkage, genome-wide association studies (GWAS), and targeted sequencing) are based on relatively sparse genotyping data, they cannot distinguish between causal variants and variants in linkage disequilibrium with unobserved causal variants. Moreover, it is unknown whether the association or linkage signals are due to single common variants, haplotypes of multiple common variants, clusters of multiple rare variants, or some combination. Finally, we cannot yet attribute specific genetic risk to individual cases and case families. <b>Therefore, the goal of the current study is to identify specific OFC risk variants in Whites by performing whole genome sequencing of parent-case trios.</b></p>
Project description:<p>The <a href="https://www.commonfund.nih.gov/KidsFirst">Gabriella Miller Kids First Pediatric Research Program</a>) (Kids First) is a trans-NIH effort initiated in response to the <a href="https://www.govtrack.us/congress/bills/113/hr2019">2014 Gabriella Miller Kids First Research Act</a> and supported by the NIH Common Fund. This program focuses on gene discovery in pediatric cancers and structural birth defects and the development of the Gabriella Miller Kids First Pediatric Data Resource (Kids First Data Resource). Both childhood cancers and structural birth defects are critical and costly conditions associated with substantial morbidity and mortality. Elucidating the underlying genetic etiology of these diseases has the potential to profoundly improve preventative measures, diagnostics, and therapeutic interventions.</p> <p>All of the WGS and phenotypic data from this study are accessible through dbGaP and <a href="https://kidsfirstdrc.org/">https://kidsfirstdrc.org</a>, where other Kids First datasets can also be accessed.</p> <p>The Kids First study of nonsyndromic orofacial cleft (OFC) birth defects in Latin American families is a whole genome sequencing study of 283 Latin-American parent-case trios drawn from ongoing collaborations led by Dr. Mary L. Marazita of the University of Pittsburgh Center for Craniofacial and Dental Genetics, and including a collaboration with Dr. Lina Moreno Uribe and Dr. Andrew Lidral of the University of Iowa. All families were ascertained through the Clinica Noel where patients with OFCs receive care from the Antioquia University School of Dentistry in Medellin, Colombia (key on-site colleagues included Dr. Luz Consuelo Valencia-Ramirez and Dr. Mauricio Arcos-Burgos). Genetic studies have shown that this population is comprised of an admixture of immigrant male Caucasians (mainly Spaniards and Basques) and native Amerindian females. Every subject has had a genetic evaluation, including a pedigree analysis for a family history of clefting and other birth defects, a pregnancy history for environmental exposures, and a complete physical exam to rule out suspected or known syndromes or environmental phenocopies. Sequencing was done by the Broad Institute sequencing center funded by the Kids First program (grant number U24-HD090743). The case in each of the Kids First OFC trios has cleft lip (CL, Figure A below), cleft palate (CP, Figure B), or both (CL+CP, Figure C): </p> <img src="GetImage.cgi?study_id=phs001420&image_name=GMKFCleft.jpg"/> <p>OFCs are genetically complex structural birth defects caused by genetic factors, environmental exposures, and their interactions. OFCs are the most common craniofacial anomalies in humans, affecting approximately 1 in 700 newborns, and are one of the most common structural birth defects worldwide. On average a child with an OFC initially faces feeding difficulties, undergoes 6 surgeries, spends 30 days in hospital, receives 5 years of orthodontic treatment, and participates in ongoing speech therapy, leading to an estimated total lifetime treatment cost of about $200,000. Further, individuals born with an OFC have higher infant mortality, higher mortality rates at all other stages of life, increased incidence of mental health problems, and higher risk for other disorders (notably including breast, brain, and colon cancers). Prior genome-wide linkage and association studies have now identified at least 18 genomic regions likely to contribute to the risk for nonsyndromic OFCs. Despite this substantial progress, the functional/pathogenic variants at OFC-associated regions are mostly still unknown. Because previous OFC genomic studies (genome-wide linkage, genome-wide association studies (GWAS), and targeted sequencing) are based on relatively sparse genotyping data, they cannot distinguish between causal variants and variants in linkage disequilibrium with unobserved causal variants. Moreover, it is unknown whether the association or linkage signals are due to single common variants, haplotypes of multiple common variants, clusters of multiple rare variants, or some combination. Finally, we cannot yet attribute specific genetic risk to individual cases and case families. <b><i>Therefore, the goal of the current study is identify specific OFC risk variants in Latin American families by performing whole genome sequencing of parent-case trios.</i></b></p>
Project description:Orofacial clefts (OFCs) are the most frequent craniofacial birth defects. An orofacial cleft (OFC) occurs as a result of deviations in palatogenesis. Cell proliferation, differentiation, adhesion, migration and apoptosis are crucial in palatogenesis. We hypothesized that deregulation of these processes in oral keratinocytes contributes to OFC. We performed microarray expression analysis on palatal keratinocytes from OFC and non-OFC individuals. Principal component analysis showed a clear difference in gene expression with 24 and 17% for the first and second component respectively. In OFC cells, 228 genes were differentially expressed (p<0.001). Gene ontology analysis showed enrichment of genes involved in β1 integrin-mediated adhesion and migration, as well as in P-cadherin expression. A scratch assay demonstrated reduced migration of OFC keratinocytes (343.6 ± 29.62 μm) vs. non-OFC keratinocytes (503.4 ± 41.81 μm, p<0.05). Our results indicate that adhesion and migration are deregulated in OFC keratinocytes, which might contribute to OFC pathogenesis.
Project description:Orofacial clefts are one of the most common birth defects, affecting 1-2 per 1000 births, and have a complex etiology. High-resolution array-based comparative genomic hybridization has increased the ability to detect copy number variants that can be causative for complex diseases such as cleft lip and/or palate. Utilizing this technique on 97 non-syndromic cleft lip and palate cases and 43 cases with cleft palate only, we identified a heterozygous deletion of Isthmin 1 in one affected case, as well as a deletion in a second case which removes putative 3' regulatory information. Isthmin 1 is a strong candidate for clefting as it is expressed in orofacial structures derived from the first branchial arch and is also in the same synexpression group as fibroblast growth factor 8 and sprouty RTK signaling antagonist 1a and 2, all of which have been associated with clefting. Copy number variants affecting Isthmin 1 are exceedingly rare in control populations, and Isthmin 1 scores as a likely haploinsufficiency locus. Confirming its role in craniofacial development, knockdown or CRISPR/Cas9-generated mutation of isthmin 1 in Xenopus laevis resulted in mild to severe craniofacial dysmorphologies, with several individuals presenting with median clefts. Moreover, knockdown of isthmin 1 produced decreased expression of LIM homeobox 8, itself a gene associated with clefting, in regions of the face that pattern the maxilla. Our study demonstrates a successful pipeline from copy number variant identification of a candidate gene to functional validation in a vertebrate model system and reveals Isthmin 1 as both a new human clefting locus as well as a key craniofacial patterning gene.