EEC-LM-ADULT syndrome caused by R319H mutation in TP63 with ectrodactyly, syndactyly, and teeth anomaly: A case report.

RATIONALE: Ectrodactyly ectodermal dysplasia-cleft lip/palate (EEC) syndrome, limb-mammary syndrome (LMS), and acro-dermato-ungual-lacrimal-tooth (ADULT) syndrome are caused by a TP63 gene disorder and have similar features. In the present article, a R319H mutation in TP63 is reported, and the correlation between genotype and phenotype is discussed based on the current case and previous literature. PATIENT CONCERNS: A 13-year-old Japanese boy had ectrodactyly in the right hand and left foot and syndactyly in the left and right foot, and tooth shape abnormalities. DIAGNOSES: Peripheral blood samples were obtained, and mutation analysis was performed. A heterozygous G>A transition at cDNA position 956 of the TP63 gene was found. The patient was diagnosed with ELA (EEC/LM/ADULT) syndrome based on his clinical features and mutation analysis results. INTERVENTIONS: The patient underwent surgery to correct the left foot malformation at 1 year of age and the right foot syndactyly at 11 years of age. OUTCOMES: No complications were observed after the first and second operations. He can walk comfortably after them, and no additional interventions will be planned in him. We continued to follow up with him up to the present. LESSONS: The concept of ELA syndrome, which is the original concept of combining 3 syndromes (EEC syndrome/LMS/ADULT syndrome) into a unique clinical entity, can help clinicians to better understand TP63-related syndromes and improve the differential diagnosis of these syndromes.

A clinical and multi­omics study of Van der Woude syndrome in three generations of a Chinese family.

Previous studies have suggested that pathogenic variants in interferon regulatoryse factor 6 (IRF6) can account for almost 70% of familial Van der Woude Syndrome (VWS) cases. However, gene modifiers that account for the phenotypic variability of IRF6 in the context of VWS remain poorly characterized. The aim of this study was to report a family with VWS with variable expressivity and to identify the genetic cause. A 4­month­old boy initially presented with cleft palate and bilateral lower lip pits. Examination of his family history identified similar, albeit milder, clinical features in another four family members, including bilateral lower lip pits and/or hypodontia. Peripheral blood samples of eight members in this three­generation family were subsequently collected, and whole­exome sequencing was performed to detect pathogenic variants. A heterozygous missense IRF6 variant with a c.1198C>T change in exon 9 (resulting in an R400W change at the amino acid level) was detected in five affected subjects, but not in the other three unaffected subjects. Moreover, subsequent structural analysis was indicative of damaged stability to the structure in the mutant IRF protein. Whole­transcriptome sequencing, expression analysis and Gene Ontology enrichment analysis were conducted on two groups of patients with phenotypic diversity from the same family. These analyses identified significant differentially expressed genes and enriched pathways in these two groups. Altogether, these findings provide insight into the mechanism underlying the variable expressivity of VWS.

Association of BMP4 polymorphisms with isolated tooth agenesis in a Chinese Han population: a case-control study.

OBJECTIVE: Tooth agenesis is a common craniofacial anomaly in human beings. Mounting evidence has demonstrated that the bone morphogenetic protein 4 gene (BMP4) plays an important role in tooth development. This case-control study was designed to evaluate the association of the polymorphism rs17563 in BMP4 gene with susceptibility of isolated human tooth agenesis in a Chinese Han population. PATIENTS AND METHODS: 335 tooth agenesis cases and 444 healthy controls were included in this study. RESULTS: Although no significant association was observed either in the overall or stratified analysis between the types and the severity of missing teeth. However, significant difference was observed between the anterior and posterior tooth agenesis (APTA) cases and the controls (p = 0.018 for allele distribution and OR = 0.39, 95% CI = 0.15-0.99). Furthermore, the heterozygote (TC) and dominant model (CC+TC) were associated with decreased risk of APTA compared with the control (phet = 0.018, ORhet = 0.39, 95% CIhet = 0.15-0.99 and pdom = 0.042, ORdom = 0.34, 95% CIdom = 0.13-0.87, respectively). CONCLUSIONS: These results indicated that rs17563 in BMP4 gene was potentially associated with APTA in Chinese Han population and further independent studies are required to verify these findings.

Investigating the etiology of multiple tooth agenesis in three sisters with severe oligodontia.

OBJECTIVES: To describe the dentofacial phenotypes of three sisters with severe non-syndromic oligodontia, to report on the mutation analysis in three genes, previously shown to cause various phenotypes of non-syndromic oligodontia and in two other suspected genes. Based on the phenotypes in the pedigree of this family, the different possible patterns of transmission are discussed. METHODS: Anamnestic data and a panoramic radiograph were taken to study the phenotype of the three sisters and their first-degree relatives. Blood samples were also taken to obtain their karyotypes and DNA samples. Mutational screening was performed for the MSX1, PAX9, AXIN2, DLX1 and DLX2 genes. RESULTS: The probands' pedigree showed evidence for a recessive or multifactorial inheritance pattern. Normal chromosomal karyotypes were found and - despite the severe oligodontia present in all three sisters - no mutation appeared to be present in the five genes studied so far in these patients. CONCLUSIONS: In the three sisters reported, their common oligodontia phenotype is not caused by mutations in the coding regions of MSX1, PAX9, AXIN2, DLX1 or DLX2 genes, but genetic factors most probably play a role as all three sisters were affected. Environmental and epigenetic factors as well as genes regulating odontogenesis need further in vivo and in vitro investigation to explain the phenotypic heterogeneity and to increase our understanding of the odontogenic processes.