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Introduction: Piebaldism is the dominantly inherited skin disorder clinically characterized by congenital stable and well circumscribed patches of leukoderma (depigmented skin) of ventral distribution, involving central forehead, frontal chest and abdomen and central portion of limbs, and by localized poliosis (white hair). Inherited or de novo mutations in proto-oncogene KIT, encoding the transmembrane tyrosine kinase receptor c-kit, underly the majority of piebaldism cases. Piebaldism is a disorder characterized by incomplete penetrance and variable expressivity.

The COVID-19 pandemic posed an increased threat to dental personnel and patients. Close encounters with patients' breath and saliva and the use of intraoral rotating instruments which disperse microscopic airborne particles both increase the possibility of environmental infection. In this study, fluorescent marker (FM) was used to assess and enhance surface cleanliness in the dental clinics and public areas of a major dental school. Initially, 574 surfaces in various areas of a dental school were marked with FM for 3 consecutive months to monitor the surface cleanliness. The initial evaluation results were visually presented to both students and para-dental and cleaning personnel during a designated educational session, and were used to stress the importance of preventing cross-contamination. Following educational intervention, 662 surfaces were re-examined for an additional 3 months, using the same method. A significant improvement in the surfaces' cleanliness (ANOVA, F (1) = 10.89, p < 0.005) was observed post-intervention. The results were more prominent in students' clinics, which were the students' cleaning responsibility. The results show that fluorescent markers can serve as an educational tool to improve strategies to control contaminated surfaces in large clinics, such as dental schools. Their use can substantially decrease the hazard of cross-contamination during the pandemic and beyond., Competing Interests: The authors declare no conflict of interest.

Whole exome sequencing (WES) has become routine in clinical practice, especially in studies of recessive hereditary diseases in inbred consanguineous families, where homozygosity of a founder mutation is assumed. Multiple members of two consanguineous families of a single Bedouin tribe were diagnosed with apparently autosomal recessive/pseudo-dominant retinitis pigmentosa (RP). Affected individuals exhibited severe visual impairment with nyctalopia, marked constriction of visual fields, markedly reduced and delayed responses on electro-retinography (ERG) and eventual loss of central vision. Combined copy-number variant (CNV) analysis, haplotype reconstruction and WES of the kindred identified two distinct novel mutations in EYS (RP25): a p.(W1817*) nonsense mutation (identified through WES) and a large deletion encompassing 9 of the 43 exons, that was missed by WES and was identified through microarray CNV analysis. Segregation analysis of both mutations demonstrated that all affected individuals were either homozygous for one of the mutations, or compound heterozygous for both. The two mutations are predicted to cause loss of function of the encoded protein and were not present in screening of 200 ethnically-matched controls. Our findings of two distinct mutations in the same gene in a single inbred kindred, identified only through combined WES and microarray CNV analysis, highlight the limitations of either CNV or WES alone, as the heterozygous deletion had normal WES read-depth values. Moreover, they demonstrate pitfalls in homozygosity mapping for disease-causing variant identification in inbred communities., (© 2018 Wiley Periodicals, Inc.)