Publications by authors named "Tamara D Busch"

Objective: The etiology of cleft palate (CP) is poorly understood compared with that of cleft lip with or without palate (CL ± P). Recently, variants in Grainyhead like transcription factor 3 () were reported to be associated with a risk for CP in European and some African populations including Nigeria, Ghana, and Ethiopia. In order to identify genetic variants that may further explain the etiology of CP, we sequenced in a South African population to determine if rare variants in are associated with the presence of syndromic or nonsyndromic CP.

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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.

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This study aimed to determine the normative facial anthropometry measurement among Nigerians using three-dimensional stereophotogrammetry analysis.This study was carried out in Lagos, Nigeria over a period of 3 years. The sample population was Nigerians of diverse ethnic groups, age 16 and above with no history of congenital or acquired craniofacial deformities.

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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.

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Mutations in IRF6, TFAP2A and GRHL3 cause orofacial clefting syndromes in humans. However, Tfap2a and Grhl3 are also required for neurulation in mice. Here, we found that homeostasis of Irf6 is also required for development of the neural tube and associated structures.

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Article Synopsis
  • Orofacial clefts, including cleft palate only (CPO) and cleft lip with or without palate (CL/P), are prevalent developmental disorders that create various clinical and psychological challenges.
  • In a study involving around 17 million genetic markers among sub-Saharan African populations, researchers identified new genetic loci associated with CPO on chromosomes 2 and 19, suggesting potential biological mechanisms.
  • The study confirmed the significance of previously known loci such as 8q24 for CL/P, along with the replication of other established genes like PAX7 and VAX1, contributing to our understanding of these conditions.
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Background: Orofacial clefts are the most common malformations of the head and neck region. Genetic and environmental factors have been implicated in the etiology of these traits.

Methods: We recently conducted genotyping of individuals from the African population using the multiethnic genotyping array (MEGA) to identify common genetic variation associated with nonsyndromic orofacial clefts.

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Article Synopsis
  • Cleft lip and/or cleft palate (CL/P) are facial birth defects influenced by genetic and environmental factors, with significant genetic associations identified mostly in noncoding regions of the genome.
  • The study focused on identifying coding variants in the GREM1 gene by analyzing DNA from 397 individuals with CL/P from sub-Saharan Africa and found two novel variants not present in control groups.
  • Results showed one variant associated with a soft palate cleft and another in a case with a bilateral cleft lip, suggesting regulatory elements, rather than coding variants, may drive the connection between GREM1 and CL/P.
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BackgroundPreterm birth (PTB) is the leading cause of neonatal mortality and morbidity. PTB is often classified according to clinical presentation as follows: idiopathic (PTB-I), preterm premature rupture of membranes (PTB-PPROM), and medically induced (PTB-M). The aim of this study was to evaluate the associations between specific candidate genes and clinical subtypes of PTB.

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Background: Orofacial clefts are congenital malformations of the orofacial region, with a global incidence of one per 700 live births. Interferon Regulatory Factor 6 () (OMIM:607199) gene has been associated with the etiology of both syndromic and nonsyndromic orofacial clefts. The aim of this study was to show evidence of potentially pathogenic variants in in orofacial clefts cohorts from Africa.

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Background: Preterm birth (PTB) is a major cause of neonatal mortality and morbidity. There is strong evidence of genetic susceptibility. Objective of this study was to identify genetic variants contributing to PTB.

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Background: In recent years, increasing numbers of preterm infants have been exposed to inhaled nitric oxide (iNO). This population has decreased methemoglobin (MetHb) reductase activity in their erythrocytes, which may increase the risk of MetHb toxicity. We sought to determine if genetic factors are associated with the observed variance in MetHb levels.

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Group B Streptococcus (GBS) causes invasive infections in human newborns. We recently showed that the GBS β-protein attenuates innate immune responses by binding to sialic acid-binding immunoglobulin-like lectin 5 (Siglec-5), an inhibitory receptor on phagocytes. Interestingly, neutrophils and monocytes also express Siglec-14, which has a ligand-binding domain almost identical to Siglec-5 but signals via an activating motif, raising the possibility that these are paired Siglec receptors that balance immune responses to pathogens.

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Article Synopsis
  • Preterm birth (PTB) is a significant health issue worldwide, and the study aimed to uncover genetic factors associated with spontaneous idiopathic PTB through whole-exome sequencing of mothers from affected families.
  • Novel genetic variants were identified in mother-daughter pairs that appeared to target specific pathways, particularly the complement and coagulation cascade, which was found to be significantly enriched in PTB cases.
  • In a larger association analysis involving Finnish nuclear families, certain genetic variants within this pathway were linked to increased PTB risk, suggesting potential avenues for screening and intervention strategies related to prematurity prevention.
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Nonsyndromic orofacial clefts are a common complex birth defect caused by genetic and environmental factors and/or their interactions. A previous genome-wide linkage scan discovered a novel locus for cleft lip with or without cleft palate (CL/P) at 9q22-q33. To identify the etiologic gene, we undertook an iterative and complementary fine mapping strategy using family-based CL/P samples from Colombia, USA and the Philippines.

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