A de novo 2.3 kb structural variant in MITF explains a novel splashed white phenotype in a Thoroughbred family.

Splashed white in horses is characterized by extensive white patterning on the legs, face and abdomen and may be accompanied by deafness. To date, seven variants in microphthalmia-associated transcription factor (MITF) and two variants in Paired Box 3 (PAX3) have been identified to explain this phenotype. A splashed white Thoroughbred stallion, whose sire and dam were not patterned, was hypothesized to have a de novo variant leading to his white coat pattern. A whole-genome sequencing candidate gene approach identified two single nucleotide variants (SNVs) in SOX10, four SNVs in MITF and a 2.3 kb deletion in MITF with the alternative allele present in this stallion but absent in the other 18 horses analyzed. All six SNVs were annotated as modifiers and were not further considered. The deletion in MITF (NC_009159.3:g.21555811_21558139delinsAAAT) encompasses exon 9 encoding a part of the helix-loop-helix domain required for DNA binding. Sanger sequencing and parentage testing confirmed that this deletion was a de novo mutation of maternal origin. Consistent with the published nomenclature, we denote this likely causal variant as SW8. Genotyping three of this stallion's offspring identified SW8 only in the nearly all-white foal that was confirmed deaf by brainstem auditory evoked response testing. This foal was also a compound heterozygote for dominant white variants (W20/W22), but to date, W variants alone have not been connected to deafness. SW8 marks the fourth de novo MITF variant in horses reported to cause white patterning. The link between deafness and all MITF variants with and without other variants impacting melanocyte development and function needs to be further explored.

[Risks and benefits of extraction of impacted third molars: A critical review of the literature. 2]. / Risques et bénéfices de l'ablation des troisième molaires incluses: revue critique de la littérature--Partie 2.

In part I of this critical review of the literature on the risks and benefits of removing impacted third molars, we have dealt with: I--Risks of non-intervention. This second part is about: II--Risks of intervention, III--Benefits of non-intervention, and, finally, IV--Benefits of intervention.

[Risks and benefits of removal of impacted third molars: critical review of the literature. 1]. / Risques et bénéfices de l'ablation des troisième molaires incluses: revue critique de la littérature--Partie 1.

Because of the ever-increasing enthusiasm that new graduates have demonstrated for practising minor oral surgery procedures, the authors believed that it would be useful to translate the results of a research project done in 1990 by Drs. David S. Precious and Paul Mercier, who are well-known oral and maxillofacial surgeons. This paper is about the risks and benefits associated with the removal of impacted third molars.

[Isolated cleft palates compared to cleft palates associated with Pierre Robin syndrome]. / Les fentes palatines isolées versus les fentes palatines du syndrome Pierre Robin.

The purpose of this study was to evaluate two variables associated with isolated cleft palate and cleft palate related to Pierre Robin syndrome, namely, sexual incidence and dental anomalies. The study demonstrated that there are more dental anomalies associated with the Pierre Robin syndrome and that girls are more affected than boys in both instances.

[Comparison of different types of cleft lip and palate in regards to dental anomalies and sexual incidence]. / Comparaison de différents types de fentes labio-palatines en évaluant les anomalies dentaires et l'incidence sexuelle.

The present study addresses two questions. Does the incidence of dental anomalies differ among the four following types of cleft lip and palate: the isolated cleft palate, the unilateral cleft lip and palate, (right or left), and the bilateral cleft lip and palate. Furthermore is the sexual incidence comparable among the four above mentioned types? Radiographic records and complete family history of clefting of 156 patients with a complete cleft lip and palate were obtained from the Cleft Lip and Palate Teams of Ste-Justine Hospital. Patients in which the cleft was part of a syndrome were excluded from the study. According to the analysis of the data, the incidence of dental anomalies was relatively high, specifically as high as 92% for the bilateral cleft lip and palate. The sexual incidence differed among the four types.

[Synthesis of current knowledge on Pierre Robin syndrome]. / Synthèse des connaissances actuelles sur le syndrome de Pierre Robin.

An analysis of the clinical features of Pierre Robin syndrome is presented. The main characteristics relative to the clinical aspect, diagnosis, etiopathogenicity and treatment are described. The prognosis and evolution of the syndrome are finally analyzed.