Ankyloglossia in Monochorionic Diamniotic and Dichorionic Diamniotic Twins: A Cross-Sectional Study

Objective: To determine the prevalence of ankyloglossia in diamniotic monochorionic and diamniotic dichorionic twins, as well as to verify the relationship between gender and type of pregnancy. Study Design: A cross-sectional observational study, carried out with 52 pairs of dichorionic/diamniotic twins and 49 monochorionic/diamniotic pairs. The data collection was carried out through the analysis of medical records and the results of the Neonatal Screening of the Tongue Frenulum Assessment Protocol in Babies, and corresponded to the period of 2 years (2020-2022). Statistical analysis of data was performed, considering the significance value of 5%. The study was approved by the Human Research Ethics Committee of the institution. Results: The statistical analysis of multiple logistic regression between the two groups of twins (Mono/Di and Di/Di) according to the socioeconomic, demographic, and clinical-epidemiological profile was statistically significant for some variables. The prevalence of ankyloglossia, according to the type of twin pregnancy, showed a statistically significant difference. There was no statistical difference in relation to sex and ankyloglossia, or between couples diagnosed with ankyloglossia according to the type of pregnancy. Conclusion: Monochorionic/diamniotic twins had a higher prevalence of ankyloglossia, regardless of gender.

Novel Candidate Genes for Non-Syndromic Tooth Agenesis Identified Using Targeted Next-Generation Sequencing

Non-syndromic tooth agenesis (ns-TA) is one of the most common dental anomalies characterized by the congenital absence of at least one permanent tooth (excluding third molars). Regarding the essential role of genetic factors in ns-TA aetiology, the present study aimed to identify novel pathogenic variants underlying hypodontia and oligodontia. In a group of 65 ns-TA patients and 127 healthy individuals from the genetically homogenous Polish population, the coding sequences of 423 candidate genes were screened using targeted next-generation sequencing. Pathogenic and likely pathogenic variants were identified in 37 (56.92%) patients, including eight nucleotide alternations of genes not previously implicated in ns-TA (CHD7, CREBBP, EVC, LEF1, ROR2, TBX22 and TP63). However, since only single variants were detected, future research is required to confirm and fully understand their role in the aetiology of ns-TA. Additionally, our results support the importance of already known ns-TA candidate genes (AXIN2, EDA, EDAR, IRF6, LAMA3, LRP6, MSX1, PAX9 and WNT10A) and provide additional evidence that ns-TA might be an oligogenic condition involving the cumulative effect of rare variants in two or more distinct genes.

Dental anomalies in non-syndromic orofacial clefts: a clinical approach

Orofacial clefts (OC) represent some of the most common congenital malformations and affect multiple structures in the craniofacial region. There are a wide range of morphological OC types within the spectrum of both non-syndromic OC (NSOC) and syndromic OC, including cleft lip (CL); cleft lip and palate (CLP) and cleft palate (CP). Here, we describe the most frequent dental anomalies seen in the permanent dentition of individuals with NSOC, comparing them between the three main cleft types (CL, CLP, CP). We present these findings from the perspective of prevalence relating to each anomaly, as well as the clinical characteristics and potential impact in the rehabilitation process. The investigation of dental anomalies associated with NSOC is important, helping to expand the phenotypic characterization of NSOC, improve initial diagnostics and establish appropriate rehabilitation and counseling.

Is ankyloglossia associated with obstructive sleep apnea?

OBJECTIVES

To investigate the evidence on the association between ankyloglossia and obstructive sleep apnea.

METHODS

An integrative literature review was carried out in the databases. Observational and interventional studies that assessed the lingual frenulum in children with sleep-disordered breathing were included. As exclusion criteria: studies in animals, in vitro, letters to the editor, expert opinions, other reviews. The selected articles were analyzed regarding the study design, sample, characterization of the lingual frenulum and sleep assessment, in addition to the main results and conclusions.

RESULTS

Ninety-seven articles were identified, but only 4 met the inclusion criteria. Two retrospective studies concluded that the untreated shortened lingual frenulum at birth is associated with obstructive sleep apnea. A prospective study concluded that there was an improvement in speech and deglutition after lingual frenectomy, in addition to improved sleep. A retrospective cohort concluded that lingual frenuloplasty combined with myofunctional therapy is effective in the treatment of snoring and mouth breathing.

CONCLUSION

The studies included in this review contribute to corroborate the association between ankyloglossia and obstructive sleep apnea.

Essential role of Msx1 in regulating anterior-posterior patterning of the secondary palate in mice

Development of the secondary palate displays molecular heterogeneity along the anterior-posterior axis; however, the underlying molecular mechanism remains largely unknown. MSX1 is an anteriorly expressed transcription repressor required for palate development. Here, we investigate the role of Msx1 in regional patterning of the secondary palate. The Wnt1-Cre-mediated expression of Msx1 (RosaMsx1^Wnt1-Cre) throughout the palatal mesenchyme leads to cleft palate in mice, associated with aberrant cell proliferation and cell death. Osteogenic patterning of the hard palate in RosaMsx1^Wnt1-Cre mice is severely impaired, as revealed by a marked reduction in palatine bone formation and decreased expression of the osteogenic regulator Sp7. Overexpression and knockout of Msx1 in mice show that the transcription repressor promotes the expression of the anterior palate-specific Alx1 but represses the expression of the medial-posterior palate genes Barx1, Meox2, and Tbx22. Furthermore, Tbx22 constitutes a direct Msx1 target gene in the secondary palate, suggesting that Msx1 can directly repress the expression of medial-posterior specific genes. Finally, we determine that Sp7 is downstream of Tbx22 in palatal mesenchymal cells, suggesting that a Msx1/Tbx22/Sp7 axis participates in the regulation of palate development. Our findings unveil a novel role for Msx1 in regulating the anterior-posterior growth and patterning of the secondary palate.

Assessment of the tongue frenulum in Beckwith-Wiedemann syndrome: Pre- and post-frenectomy findings

AIM

To report the pre- and post-frenectomy findings of a patient with Beckwith-Wiedemann syndrome.

METHODS AND RESULTS

Clinical case report of a patient with a confirmed genetic-molecular diagnosis of the referred syndrome. The minor was evaluated and reassessed by the protocol for the evaluation of the tongue's frenulum for babies in two moments: pre-surgical and 2 months after the frenectomy. The surgical procedure was performed using the traditional technique and, after the procedure, the minor was breastfed and received photobiomodulation with a red laser. The minor obtained 16 points in the neonatal tongue screening test, indicating the need for a frenectomy. Thus, she was referred to a dentist for surgery. After the surgical procedure, macroglossia was observed as a maternal complaint (previously not mentioned). The wound healing was satisfactory, and the total score obtained in the reapplication of the protocol (five points) showed functional results of improvements in sucking and tongue mobility, justifying the importance of the frenectomy.

CONCLUSION

Frenectomy, despite showing macroglossia related to the Beckwith-Wiedemann syndrome, allowed anatomical and functional advances of the tongue in the present clinical case.

T-Box Transcription Factor 22 Is an Immune Microenvironment-Related Biomarker Associated With the BRAF V600E Mutation in Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) is the most common malignant disease in endocrine systems. T-box transcription factor 22 (TBX22) is a phylogenetically conserved family member that has not been widely characterized in cancers. In this study, we explored the potential clinical significance and biological functions of TBX22 in PTC. Comprehensive analyses of TBX22 were based on the public databases and our local qRT-PCR cohort. We observed that TBX22 was significantly downregulated in PTC compared with normal tissues. TBX22 was associated with several clinicopathological factors in PTC. Low TBX22 expression correlated with BRAF ^V600E and TERT mutation. Functional enrichment analysis revealed that cancer-related pathways and immune progress were closely associated with TBX22 in PTC. In TBX22-low PTC, high immune infiltration levels with increased CD8⁺ T cells, natural killer, M1 macrophages, and T-regulatory cells were observed. TBX22 was negatively correlated with the activity of different steps of the anticancer immunity cycle. Functionally, overexpression of TBX22 inhibited the proliferation, invasion, and migration in PTC cells, while knocking down of TBX22 showed the opposite effects. The present findings disclose that TBX22, as an immune microenvironment-related biomarker, could be an important tumor suppresser gene and might inform the management of PTC patients better.

Genetic Factors in Nonsyndromic Orofacial Clefts

Orofacial clefts (OFCs) are the most common congenital birth defects in humans and immediately recognized at birth. The etiology remains complex and poorly understood and seems to result from multiple genetic and environmental factors along with gene-environment interactions. It can be classified into syndromic (30%) and nonsyndromic (70%) clefts. Nonsyndromic OFCs include clefts without any additional physical or cognitive deficits. Recently, various genetic approaches, such as genome-wide association studies (GWAS), candidate gene association studies, and linkage analysis, have identified multiple genes involved in the etiology of OFCs. This article provides an insight into the multiple genes involved in the etiology of OFCs. Identification of specific genetic causes of clefts helps in a better understanding of the molecular pathogenesis of OFC. In the near future, it helps to provide a more accurate diagnosis, genetic counseling, personalized medicine for better clinical care, and prevention of OFCs.

Position-dependent correlation between TBX22 exon 5 methylation and palatal shelf fusion in the development of cleft palate

DNA methylation is essential for spatiotemporally-regulated gene expression in embryonic development. TBX22 (Chr X: 107667964-107688978) functioning as a transcriptional repressor affects DNA binding, sumoylation, and transcriptional repression associated with X-linked cleft palate. This study aimed to explore the relationship and potential mechanism between TBX22 exon 5 methylation and palatal shelf fusion induced by all-trans retinoic acid (ATRA). We performed DNA methylation profiling, using MethylRAD-seq, after high throughput sequencing of mouse embryos from control (n=9) and ATRA-treated (to induce cleft palate, n=9) C57BL/6J mice at embryonic gestation days(E) 13.5, 14.5 and 16.5. TBX22 exon 5 was hyper-methylated at the CpG site at E13.5 (P=0.025, log2FC=1.5) and E14.5 (P=0.011, log2FC:1.5) in ATRA-treated, whereas methylation TBX22 exon 5 at the CpG site was not significantly different at E16.5 (P=0.808, log2FC=-0.2) between control and ATRA-treated. MSP results showed a similar trend consistent with the MethylRAD-seq results. qPCR showed the change in TBX22 exon 5 expression level negatively correlated with its TBX22 exon 5 methylation level. These results indicate that changes in TBX22 exon 5 methylation might play an important regulatory role during palatal shelf fusion, and may enlighten the development of novel epigenetic biomarkers in the treatment of CP in the future.

Lingual frenotomy in neonates: past, present, and future

During the last decade, increasing awareness of breastfeeding and its health benefits has not been reflected in the provision of lingual frenotomy in neonates with tongue-tie. This could be because of inconsistencies in our understanding of the importance and treatment of ankyloglossia. In this review, we discuss the current clinical guidance on diagnosis and management, and the future of such a service in the early postpartum period.

The Role of the Wnt Signaling Pathway in Upper Jaw Development of Chick Embryo

Cleft lip with or without cleft palate (CLP) usually results from a failure of the medial nasal prominences to fuse with the lateral and maxillary prominences. This failure inhibits facial morphogenesis regulated by several major morphogenetic signaling pathways. We hypothesized that CLP results from the failure of the Wnt signaling pathway. To examine whether Wnt signaling can influences upper jaw development, we applied beads soaked with Dickkopf-1 (Dkk-1), Alsterpaullone (AL) or Wnt3a to the right side of the maxillary prominence of the chick embryo. The embryo showed a defect of the maxilla on the treated side, and skeletal staining revealed hypoplasia of the premaxilla and palatine bone as a result of Dkk-1-soaked bead implantation. 5-bromo-2'-deoxyuridine (BrdU)-positive cell numbers in the treated maxillary prominence were significantly lower at both 24 and 48 hr after implantation. Down-regulation of the expression of Bmp4, Tbx22, Sox9, and Barx1 was confirmed in the maxillary prominence treated with Dkk-1, which indicated that the deformity of the maxillary bone was controlled by gene targets of the Wnt signaling pathway. Expression of N-cadherin was seen immunohistochemically in the maxillary prominences of embryos at 6 hr and increased at 24 hr after AL treatment. Wnt signaling enhanced by AL or Wnt3a up-regulated the expression levels of Msx1, Bmp4, Tbx22, Sox9, and Barx1. Our data suggest that the Wnt signaling pathway regulates maxillary morphogenesis and growth through Bmp4, Tbx22, Sox9, and Barx1. Wnt signaling might regulate N-cadherin expression via Msx1, resulting in cell aggregation for osteochondrogenesis.

DNA hypermethylation of Fgf16 and Tbx22 associated with cleft palate during palatal fusion

OBJECTIVE

Cleft palate (CP) is a congenital birth defect caused by the failure of palatal fusion. Little is known about the potential role of DNA methylation in the pathogenesis of CP. This study aimed to explore the potential role of DNA methylation in the mechanism of CP.

METHODOLOGY

We established an all-trans retinoic acid (ATRA)-induced CP model in C57BL/6J mice and used methylation-dependent restriction enzymes (MethylRAD, FspEI) combined with high-throughput sequencing (HiSeq X Ten) to compare genome-wide DNA methylation profiles of embryonic mouse palatal tissues, between embryos from ATRA-treated vs. untreated mice, at embryonic gestation day 14.5 (E14.5) (n=3 per group). To confirm differentially methylated levels of susceptible genes, real-time quantitative PCR (qPCR) was used to correlate expression of differentially methylated genes related to CP.

RESULTS

We identified 196 differentially methylated genes, including 17,298 differentially methylated CCGG sites between ATRA-treated vs. untreated embryonic mouse palatal tissues (P<0.05, log2FC>1). The CP-related genes Fgf16 (P=0.008, log2FC=1.13) and Tbx22 (P=0.011, log2FC=1.64,) were hypermethylated. Analysis of Fgf16 and Tbx22, using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), identified 3 GO terms and 1 KEGG pathway functionally related to palatal fusion. The qPCR showed that changes in expression level negatively correlated with methylation levels.

CONCLUSIONS

Taken together, these results suggest that hypermethylation of Fgf16 and Tbx22 is associated with decreased gene expression, which might be responsible for developmental failure of palatal fusion, eventually resulting in the formation of CP.

Unmasking familial CPX by WES and identification of novel clinical signs

Mutations in the T-Box transcription factor gene TBX22 are found in X-linked Cleft Palate with or without Ankyloglossia syndrome (CPX syndrome). In addition to X-linked inheritance, ankyloglossia, present in the majority of CPX patients, is an important diagnostic marker, but it is frequently missed or unreported, as it is a "minor" feature. Other described anomalies include cleft lip, micro and/or hypodontia, and features of CHARGE syndrome. We conducted whole exome sequencing (WES) on 22 individuals from 17 "a priori" non-syndromic cleft lip and/or cleft palate (CL/P) families. We filtered the data for heterozygous pathogenic variants within a set of predefined candidate genes. Two canonical splice-site mutations were found in TBX22. Detailed re-phenotyping of the two probands and their families unravelled orofacial features previously not associated with the CPX phenotypic spectrum: choanal atresia, Pierre-Robin sequence, and overgrowths on the posterior edge of the hard palate, on each side of the palatal midline. This study emphasizes the importance of WES analysis in familial CLP cases, combined with deep (reverse) phenotyping in "a priori" non-syndromic clefts.

Tooth agenesis and orofacial clefting: genetic brothers in arms?

Tooth agenesis and orofacial clefts represent the most common developmental anomalies and their co-occurrence is often reported in patients as well in animal models. The aim of the present systematic review is to thoroughly investigate the current literature (PubMed, EMBASE) to identify the genes and genomic loci contributing to syndromic or non-syndromic co-occurrence of tooth agenesis and orofacial clefts, to gain insight into the molecular mechanisms underlying their dual involvement in the development of teeth and facial primordia. Altogether, 84 articles including phenotype and genotype description provided 9 genomic loci and 26 gene candidates underlying the co-occurrence of the two congenital defects: MSX1, PAX9, IRF6, TP63, KMT2D, KDM6A, SATB2, TBX22, TGFα, TGFβ3, TGFβR1, TGFβR2, FGF8, FGFR1, KISS1R, WNT3, WNT5A, CDH1, CHD7, AXIN2, TWIST1, BCOR, OFD1, PTCH1, PITX2, and PVRL1. The molecular pathways, cellular functions, tissue-specific expression and disease association were investigated using publicly accessible databases (EntrezGene, UniProt, OMIM). The Gene Ontology terms of the biological processes mediated by the candidate genes were used to cluster them using the GOTermMapper (Lewis-Sigler Institute, Princeton University), speculating on six super-clusters: (a) anatomical development, (b) cell division, growth and motility, (c) cell metabolism and catabolism, (d) cell transport, (e) cell structure organization and (f) organ/system-specific processes. This review aims to increase the knowledge on the mechanisms underlying the co-occurrence of tooth agenesis and orofacial clefts, to pave the way for improving targeted (prenatal) molecular diagnosis and finally to reflect on therapeutic or ultimately preventive strategies for these disabling conditions in the future.

MORN5 Expression during Craniofacial Development and Its Interaction with the BMP and TGFβ Pathways

MORN5 (MORN repeat containing 5) is encoded by a locus positioned on chromosome 17 in the chicken genome. The MORN motif is found in multiple copies in several proteins including junctophilins or phosphatidylinositol phosphate kinase family and the MORN proteins themselves are found across the animal and plant kingdoms. MORN5 protein has a characteristic punctate pattern in the cytoplasm in immunofluorescence imaging. Previously, MORN5 was found among differentially expressed genes in a microarray profiling experiment of the chicken embryo head. Here, we provided in situ hybridization to analyse, in detail, the MORN5 expression in chick craniofacial structures. The expression of MORN5 was first observed at stage HH17-18 (E2.5). MORN5 expression gradually appeared on either side of the primitive oral cavity, within the maxillary region. At stage HH20 (E3), prominent expression was localized in the mandibular prominences lateral to the midline. From stage HH20 up to HH29 (E6), there was strong expression in restricted regions of the maxillary and mandibular prominences. The frontonasal mass (in the midline of the face) expressed MORN5, starting at HH27 (E5). The expression was concentrated in the corners or globular processes, which will ultimately fuse with the cranial edges of the maxillary prominences. MORN5 expression was maintained in the fusion zone up to stage HH29. In sections MORN5 expression was localized preferentially in the mesenchyme. Previously, we examined signals that regulate MORN5 expression in the face based on a previous microarray study. Here, we validated the array results with in situ hybridization and QPCR. MORN5 was downregulated 24 h after Noggin and/or RA treatment. We also determined that BMP pathway genes are downstream of MORN5 following siRNA knockdown. Based on these results, we conclude that MORN5 is both regulated by and required for BMP signaling. The restricted expression of MORN5 in the lip fusion zone shown here supports the human genetic data in which MORN5 variants were associated with increased risk of non-syndromic cleft lip with or without cleft palate.

A frequent phenotype for paediatric sleep apnoea: short lingual frenulum

A short lingual frenulum has been associated with difficulties in sucking, swallowing and speech. The oral dysfunction induced by a short lingual frenulum can lead to oral-facial dysmorphosis, which decreases the size of upper airway support. Such progressive change increases the risk of upper airway collapsibility during sleep.

Clinical investigation of the oral cavity was conducted as a part of a clinical evaluation of children suspected of having sleep disordered breathing (SDB) based on complaints, symptoms and signs. Systematic polysomnographic evaluation followed the clinical examination. A retrospective analysis of 150 successively seen children suspected of having SDB was performed, in addition to a comparison of the findings between children with and without short lingual frenula.

Among the children, two groups of obstructive sleep apnoea syndrome (OSAS) were found: 1) absence of adenotonsils enlargement and short frenula (n=63); and 2) normal frenula and enlarged adenotonsils (n=87). Children in the first group had significantly more abnormal oral anatomy findings, and a positive family of short frenulum and SDB was documented in at least one direct family member in 60 cases.

A short lingual frenulum left untreated at birth is associated with OSAS at later age, and a systematic screening for the syndrome should be conducted when this anatomical abnormality is recognised.

A short lingual frenulum left untreated at birth is associated with obstructive sleep apnoea syndrome at a later agehttp://ow.ly/6kMQ30163nG

Ankyloglossia with cleft lip: A rare case report

Ankyloglossia or tongue-tie is a congenital anomaly affecting the tongue, which is characterized by thick, short lingual frenulum. This condition causes many difficulties such as limited tongue protrusion, breastfeeding difficulties, speech impairment and lack of self-confidence. It is very rarely associated with any other congenital craniofacial disorders such as cleft lip, X-linked cleft palate, Van der Woude syndrome, Smith-Lemli-Opitz syndrome, Orofacial digital syndrome, Beckwith Weidman syndrome or Simpson-Golabi-Behmel syndrome. This article presents a rare case of ankyloglossia associated with cleft lip treated with diode laser in a 12-year-old Indian boy who had undergone surgical correction of associated cleft lip soon after birth. Correction of ankyloglossia at a young age would lead to enhanced phonetics, improved oral hygiene, and overall personality development.

Tongue-tie and frenotomy in infants with breastfeeding difficulties: achieving a balance

AIMS

Currently there is debate on how best to manage young infants with tongue-tie who have breastfeeding problems. One of the challenges is the subjectivity of the outcome variables used to assess efficacy of tongue-tie division. This structured review documents how the argument has evolved. It proposes how best to assess, inform and manage mothers and their babies who present with tongue-tie related breastfeeding problems.

METHODS

Databases were searched for relevant papers including Pubmed, Medline, and the Cochrane Library. Professionals in the field were personally contacted regarding the provision of additional data. Inclusion criteria were: infants less than 3 months old with tongue-tie and/or feeding problems. The exclusion criteria were infants with oral anomalies and neuromuscular disorders.

RESULTS

There is wide variation in prevalence rates reported in different series, from 0.02 to 10.7%. The most comprehensive clinical assessment is the Hazelbaker Assessment Tool for lingual frenulum function. The most recently published systematic review of the effect of tongue-tie release on breastfeeding concludes that there were a limited number of studies with quality evidence. There have been 316 infants enrolled in frenotomy RCTs across five studies. No major complications from surgical division were reported. The complications of frenotomy may be minimised with a check list before embarking on the procedure.

CONCLUSIONS

Good assessment and selection are important because 50% of breastfeeding babies with ankyloglossia will not encounter any problems. We recommend 2 to 3 weeks as reasonable timing for intervention. Frenotomy appears to improve breastfeeding in infants with tongue-tie, but the placebo effect is difficult to quantify. Complications are rare, but it is important that it is carried out by a trained professional.

Loss-of-function mutation in the X-linked TBX22 promoter disrupts an ETS-1 binding site and leads to cleft palate

The cleft palate only (CPO) is a common congenital defect with complex etiology in humans. The molecular etiology of the CPO remains unknown. Here, we report a loss-of-function mutation in X-linked TBX22 gene (T-box 22) in a six-generation family of the CPO with obvious phenotypes of both cleft palate and hyper-nasal speech. We identify a functional -73G>A mutation in the promoter of TBX22, which is located at the core-binding site of transcription factor ETS-1 (v-ets avian erythroblastosis virus E26 oncogene homolog 1). Phylogenetic analysis showed that the sequence around the -73G>A mutation site is specific in primates. The mutation was detected in all five affected male members cosegregating with the affected phenotype and heterozygote occurred only in some unaffected females of the family, suggesting an X-linked transmission of the mutation in the family. The -73G>A variant is a novel single nucleotide mutation. Cell co-transfections indicated that ETS-1 could activate the TBX22 promoter. Moreover, EMSA and ChIP assays demonstrated that the allele A disrupts the binding site of ETS-1, thus markedly decreases the activity of the TBX22 promoter, which is likely to lead to the birth defect of the CPO without ankyloglossia. These results suggest that a loss-of-function mutation in the X-linked TBX22 promoter may cause the cleft palate through disruption of TBX22-ETS-1 pathway.

Investigation of Parental Transmission of RUNX2 Single Nucleotide Polymorphism and Its Association with Nonsyndromic Cleft Lip with or Without Palate

Objective

To investigate the association and parental transmission of RUNX2 single nucleotide polymorphisms (SNPs) with risk of nonsyndromic cleft lip with or without cleft palate (NS-CL±P).

Design

Four RUNX2 SNPs in 142 Korean NS-CL±P families (nine cleft lip, 26 cleft lip and alveolus, and 107 cleft lip and palate; 76 trios and 66 dyads) were genotyped. The minor allele frequency, heterozygosity, and chi-square test for Hardy-Weinberg equilibrium at each SNP were computed between parents. Pairwise linkage disequilibrium was computed as D′ and r2 for all SNPs. Both allelic and genotypic transmission disequilibrium tests (TDTs) were performed for individual SNPs using a family-based association test program. Sliding windows of haplotypes consisting of two to four SNPs were tested using a haplotype-based association test program. Genotypic odds ratios (GORs) were calculated from conditional logistic regression models. Parent-of-origin effects were assessed using transmission asymmetry test and parent-of-origin likelihood ratio test.

Results

The family-based TDT showed significant evidence of linkage and association at rs1934328 ( P = .001). In the haplotype analysis, two, three, and four haplotypes containing rs1934328 revealed significant associations ( P = .0017, P = .0022, and P = .0020, respectively). The genotypes A/T and T/T at rs1934328 were significantly associated with NS-CL±P compared with the genotype A/A (GOR = 2.75, 95% confidence interval [CI] = 1.39–5.45, P =0.0019 in the dominant model; GOR = 5.38, 95% CI = 1.34–21.68, P = .0046 in the additive model). However, no parent-of origin effect was observed.

Conclusion

These findings suggest possible involvement of RUNX2-rs 194328 in the etiology of NS-CL±P in Korean cleft-parent trios without excess parental transmission.

WNT10A mutations also associated with agenesis of the maxillary permanent canines, a separate entity

Agenesis or isolated hypodontia of the maxillary permanent canines is a very rare dental anomaly. We report on nine unrelated Thai patients with this condition. Three of them had one affected parent. Three heterozygous missense mutations (p.Arg171Cys; p.Gly213Ser; and IVS2+1G>A) were identified in WNT10A in six patients. The p.Gly213Cys mutation was found in four patients. One of the patients who had p.Gly213Ser mutation also had peg-shaped (microdontia of the) maxillary lateral incisors with dens invaginatus. The mothers of two patients who carried the same mutation as their affected sons (p.Gly213Ser and p.Arg171Cys) had microdontia of the maxillary permanent lateral incisor. Our study has demonstrated for the first time that agenesis of the maxillary permanent canines is a distinct entity, associated with mutations in WNT10A. Inheritance appears to be autosomal dominant. Agenesis of the maxillary permanent canines may accompany by microdontia of the maxillary permanent lateral incisors and dens invaginatus of the maxillary permanent lateral incisors. Mutations could not be identified in the coding exons of WNT10A in three patients. They might be located outside the coding exons, including the promoter regions. However, it is likely that agenesis of the maxillary permanent canines is a heterogeneous disorder.

Clinical guidelines and management of ankyloglossia with 1-year followup: report of 3 cases

The tongue is an important oral structure that affects speech, position of teeth, periodontal tissue, nutrition, swallowing, nursing, and certain social activities. Ankyloglossia (tongue tie) is a congenital anomaly characterized by an abnormally short, thick lingual frenulum which affects movement of tongue. Though the effect of ankyloglossia in general appears to be a minor condition, but a major difference exists concerning the guidelines for tongue-tie division. There are no accepted practical criteria for the management of such condition, and hence this paper aims at bringing all the compilation in examination, diagnosis, treatment, and management of tongue tie together for better clinical approach.

Non-syndromic cleft palate: analysis of TBX22 exon 5 gene mutation

INTRODUCTION

This study aimed to investigate the mutation of T-box transcription factor TBX22 exon 5 in children with non-syndromic cleft palate. Four mutations in TBX22 exon 5 in X-linked cleft palate with ankyloglossia (CPX) patients had been identified in the previous studies. The study used the syndromic cleft palate susceptibility gene as a candidate gene for more common non-syndromic cleft palate.

MATERIAL AND METHODS

A family-based study with parents and their children composing parent-child trios was performed in this research. Twenty children with non-syndromic cleft palate and 38 healthy parents were enrolled. TBX22 exon 5 was examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing. The peaks of the sequence diagrams were analyzed using chromas221 and the results of sequencing were proofread using dnastar6.13. The index of the transmission disequilibrium test (TDT) was calculated through McNemar testing.

RESULTS

We have not found the presence of any mutation of TBX22 exon 5 reported in syndromic cleft palate patients in references. The index of TDT was 0.56 and showed no statistically significant difference (p<0.05). No TBX22 exon 5 mutation was found in the 20 children.

CONCLUSIONS

Mutation of TBX22 exon 5 is not associated with non-syndromic cleft palate in the population of Jiangzhe areas in China.

TBX22 and tongue-tie

OBJECTIVE

To resolve if TBX22 mutations cause isolated tongue-tie in the Finnish population.

DESIGN

Mutation analysis of the coding region of the TBX22 gene in 50 Finnish isolated tongue-tie patients and 61 control samples.

RESULTS

One putative sequence variation was identified from two male patients, but whether this represents a polymorphism or causative mutation remains unknown.

CONCLUSIONS

Mutations in the coding region of the TBX22 gene are not a major cause of ankyloglossia in the Finnish population and do not explain the sex difference or inheritance of tongue-tie.

Phylomedicine: an evolutionary telescope to explore and diagnose the universe of disease mutations

Modern technologies have made the sequencing of personal genomes routine. They have revealed thousands of nonsynonymous (amino acid altering) single nucleotide variants (nSNVs) of protein-coding DNA per genome. What do these variants foretell about an individual's predisposition to diseases? The experimental technologies required to carry out such evaluations at a genomic scale are not yet available. Fortunately, the process of natural selection has lent us an almost infinite set of tests in nature. During long-term evolution, new mutations and existing variations have been evaluated for their biological consequences in countless species, and outcomes are readily revealed by multispecies genome comparisons. We review studies that have investigated evolutionary characteristics and in silico functional diagnoses of nSNVs found in thousands of disease-associated genes. We conclude that the patterns of long-term evolutionary conservation and permissible sequence divergence are essential and instructive modalities for functional assessment of human genetic variations.

TBX22 mutation associated with cleft lip/palate, hypodontia, and limb anomaly

Mutations in TBX22 are known causes of cleft palate with/without ankyloglossia. We identified a hemizygous missense c.452G>T (p.Arg151Leu) mutation in a Thai boy who had unilateral complete cleft lip and palate, agenesis of a maxillary second premolar, ankyloglossia, hypoplastic carpal bones, and hypoplastic right thumb. Our study has demonstrated that TBX22 mutation is associated not only with cleft palate and ankyloglossia, but also cleft lip and palate and tooth agenesis. Phenotypic variability caused by a single nucleotide substitution is clearly demonstrated.