Epigenetic data could help identify risk factors for orofacial clefts, either by revealing a causal role for epigenetic mechanisms in causing clefts or by capturing information about causal genetic or environmental factors. Given the evidence that different subtypes of orofacial cleft have distinct aetiologies, we explored whether children with different cleft subtypes showed distinct epigenetic profiles. In whole-blood samples from 150 children from the Cleft Collective cohort study, we measured DNA methylation at over 450,000 sites on the genome. We then carried out epigenome-wide association studies (EWAS) to test the association between methylation at each site and cleft subtype (cleft lip only (CLO) n = 50; cleft palate only (CPO) n = 50; cleft lip and palate (CLP) n = 50). We also compared methylation in the blood to methylation in the lip or palate tissue using genome-wide data from the same 150 children and conducted an EWAS of CLO compared to CLP in lip tissue. We found four genomic regions in blood differentially methylated in CLO compared to CLP, 17 in CPO compared to CLP and 294 in CPO compared to CLO. Several regions mapped to genes that have previously been implicated in the development of orofacial clefts (for example, TBX1, COL11A2, HOXA2, PDGFRA), and over 250 associations were novel. Methylation in blood correlated with that in lip/palate at some regions. There were 14 regions differentially methylated in the lip tissue from children with CLO and CLP, with one region (near KIAA0415) showing up in both the blood and lip EWAS. Our finding of distinct methylation profiles in different orofacial cleft (OFC) subtypes represents a promising first step in exploring the potential role of epigenetic modifications in the aetiology of OFCs and/or as clinically useful biomarkers of OFC subtypes.

Objectives: A systematic review and meta-analysis to determine the association between active maternal smoking and cleft lip and palate etiology. Data sources: Medline, Embase, Web of Science and the Cochrane Library from inception to November, 2020. Study selection: Observational studies of cigarette smoking habits in pregnant women. Outcomes included cleft lip and/or palate, cleft lip ± palate and cleft palate only. Data analysis: Publication bias analyses were performed and the Newcastle Ottawa scales were used to assess study quality. Fixed or random effect models were used in the meta-analysis, dependent on risk of statistical heterogeneity. Results: Forty-five studies were eligible for inclusion of which 11 were cohort and 34 were case–control studies. Sixteen studies were of sufficient standard for inclusion in the meta-analysis. The summary odds ratio for the association between smoking and cleft lip and/or palate was 1.42 (95%CI 1.27-1.59) with a population attributable fraction of 4% (95%CI 3%-5%). There was limited evidence to show a dose–response effect of smoking. Conclusions: This review reports a moderate association between maternal smoking and orofacial cleft but the overall quality of the conventional observational studies included was poor. There is a need for high quality and novel research strategies to further define the role of smoking in the etiology of cleft lip and palate.

Structured Objectives: To investigate centre‐level variation in speech intervention and outcome and factors associated with a speech disorder in children in Cleft Care UK (CCUK).Setting and Sample Population: Two hundred and sixty‐eight 5‐year‐old British children with non‐syndromic unilateral cleft lip and palate recruited to CCUK.Materials and Methods: Centre‐based therapists undertook audio‐video recordings. Perceptual analysis was undertaken using the CAPS‐A tool. Speech outcomes were based on structural and articulation scores, and intelligibility/distinctiveness. Between‐centre variation in treatment and outcomes were examined using multilevel models. These models were extended to estimate the association between a range of factors (hearing loss, speech intervention, fistula, secondary speech surgery for velopharyngeal insufficiency, socio‐economic status, gender, and parental happiness with speech) and speech outcomes.Results: There was centre‐level variation in secondary speech surgery, speech intervention, structure and intelligibility outcomes. Children with a history of speech intervention had a lower odds of poor intelligibility/distinctiveness, 0.1 (95% CI: 0.0‐0.4). Parental concern was associated with a higher odds of poor intelligibility/distinctiveness, 13.2 (95% CI: 4.9‐35.1). Poor speech outcomes were associated with a fistula, secondary speech surgery and history of hearing loss.Conclusions: Within the centralized service there is centre‐level variation in secondary speech surgery, intervention and speech outcomes. These findings support the importance of early management of fistulae, effective management of velopharyngeal insufficiency and hearing impairment, and most importantly speech intervention in the preschool years. Parental concern about speech is a good indicator of speech status.

The mammalian face is assembled in utero in a series of complex and interdependent molecular, cell and tissue processes. The orofacial complex appears to be exquisitely sensitive to genetic and environmental influence and this explains why clefts of the lip and palate are the most common congenital anomaly in humans (one in 700 live births). In this study, microarray technology was used to identify genes that may play pivotal roles in normal murine palatogenesis. mRNA was isolated from murine embryonic palatal shelves oriented vertically (before elevation), horizontally (following elevation, before contact), and following fusion. Changes in gene expression between the three different stages were analyzed with GeneChip® microarrays. A number of genes were upregulated or downregulated, and large changes were seen in the expression of loricrin, glutamate decarboxylase, gamma‐amino butyric acid type A receptor beta3 subunit, frizzled, Wnt‐5a, metallothionein, annexin VIII, LIM proteins, Sox1, plakophilin1, cathepsin K and creatine kinase. In this paper, the changes in genetic profile of the developing murine palate are presented, and the possible role individual genes/proteins may play during normal palate development are discussed. Candidate genes with a putative role in cleft palate are also highlighted.