Preaxial polydactyly associated with a MSX1 mutation and report of two novel mutations

Evaluation of genome-wide association signals for nonsyndromic cleft lip with or without cleft palate in a multiethnic Brazilian population

OBJECTIVE

To evaluate previous nonsyndromic cleft lip with or without cleft palate (NSCL±P) associated signals in 4p16.2, 8p11.23, 12q13.13, 12q13.2 and 17q21.32 in a multiethnic Brazilian cohort.

DESIGN

The single nucleotide polymorphisms (SNPs) rs34246903 in 4p16.2, rs13317 in 8p11.23 (FGFR1, fibroblast growth factor receptor 1), rs3741442 in 12q13.13, rs705704 in 12q13.2 and rs4968247 in 17q21.32 were genotyped with TaqMan allelic discrimination assays in a case-control sample including 801 NSCL±P patients [233 nonsyndromic cleft lip (NSCLO) and 568 nonsyndromic cleft lip and palate (NSCLP)] and 881 healthy controls. Multiple logistic regression analyses, considering sex and genomic ancestry as covariates, were conducted, and the p value was adjusted with Bonferroni multiple correction testing (p ≤ 0.01).

RESULTS

Although several associations were identified, those that resisted the multiple correction testing involved the alleles and genotypes of rs34246903 and rs13317. The NSCLO group had a lower frequency of the minor C allele of rs34246903 compared to controls, giving an odds ratio (OR) of 0.74 [95% confidence interval (CI): 0.59-0.93, p = 0.01]. The rs34246903 CC genotype (homozygous) and the recessive model revealed significant protective associations with NSCLO, yielding ORs of 0.50 (95% CI: 0.29-0.85, p = 0.005) and 0.55 (95% CI: 0.33-0.93, p = 0.01) respectively. The presence of C variant allele of rs13317 (OR: 0.81, 95% CI: 0.69-0.96, p = 0.01) as well the TC genotype (OR: 0.77, 95% CI: 0.62-0.94, p = 0.01) and the dominant model (OR: 0.77, 95% CI: 0.63-0.94, p = 0.009) showed significant associations with reduced risk of NSCL±P.

CONCLUSION

Our study is the first to support the association of rs34246903 (4p16.2) with NSCLO and rs13317 within FGFR1 with NSCL±P in the highly admixed Brazilian population. Further studies are needed to determine the functionality of those SNPs or to identify the causal markers in linkage disequilibrium with those susceptibility markers.

Orthodontic-Surgical Approach for Treating Skeletal Class III Malocclusion With Severe Maxillary Deficiency in Isolated Cleft Palate

Orthodontic treatment in patients with orofacial cleft such as cleft lip and palate or isolated cleft palate is challenging, especially when the patients exhibit severe maxillary growth retardation. To correct this deficiency, maxillary expansion and protraction can be performed in the first phase of orthodontic treatment. However, in some cases, the malocclusion cannot be corrected by these procedures, and thus, skeletal discrepancy remains when the patients are adolescents. These remaining problems occasionally require various orthognathic treatments according to the degree of the discrepancy. Here, we describe one case of a female with isolated cleft palate and hand malformation who exhibited severe maxillary deficiency until her adolescence and was treated with multiple orthognathic surgeries, including surgically assisted maxillary expansion (surgically assisted rapid palatal expansion), LeFort I osteotomy, and bilateral sagittal split osteotomy in order to correct severe skeletal discrepancy and malocclusion. The treatment resulted in balanced facial appearance and mutually protected occlusion with good stability. The purpose of this case report is to show the orthodontic treatment outcome of 1 patient who exhibited isolated cleft palate and subsequent severe skeletal deformities and malocclusion which was treated by an orthodontic-surgical approach.

Genome-wide analyses of non-syndromic cleft lip with palate identify 14 novel loci and genetic heterogeneity

Non-syndromic cleft lip with palate (NSCLP) is the most serious sub-phenotype of non-syndromic orofacial clefts (NSOFC), which are the most common craniofacial birth defects in humans. Here we conduct a GWAS of NSCLP with multiple independent replications, totalling 7,404 NSOFC cases and 16,059 controls from several ethnicities, to identify new NSCLP risk loci, and explore the genetic heterogeneity between sub-phenotypes of NSOFC. We identify 41 SNPs within 26 loci that achieve genome-wide significance, 14 of which are novel (RAD54B, TMEM19, KRT18, WNT9B, GSC/DICER1, PTCH1, RPS26, OFCC1/TFAP2A, TAF1B, FGF10, MSX1, LINC00640, FGFR1 and SPRY1). These 26 loci collectively account for 10.94% of the heritability for NSCLP in Chinese population. We find evidence of genetic heterogeneity between the sub-phenotypes of NSOFC and among different populations. This study substantially increases the number of genetic susceptibility loci for NSCLP and provides important insights into the genetic aetiology of this common craniofacial malformation.

Non-syndromic cleft lip with palate is a common birth defect of unknown aetiology. Here, the authors discover 14 new genes associated with this condition, and show genetic heterogeneity in this and other non-syndromic orofacial clefting disorders.