A Survey for Aedes aegypti in Delaware and the Virus-Positive Pool Rates of Aedes albopictus and Aedes triseriatus for West Nile and Zika Viruses.

The introduction of Zika virus to the USA in 2015 engendered heightened interest in its known vectors. Aedes aegypti is the primary vector, with Ae. albopictus considered a potential secondary vector, together with several other possible marginal vectors. In Delaware, Ae. aegypti has been collected rarely, but no breeding populations were detected during past intensive statewide surveillance efforts. However, there is an abundance of Ae. albopictus statewide. Both species are container breeders and are peri-domestic-increasing the risk for virus transmission to humans. From July through September 2017, Delaware Mosquito Control conducted surveillance in 16 container-breeding hot spots to search for Ae. aegypti, and also ascertain the virus-positive pool rates of Ae. albopictus and Ae. triseriatus for West Nile virus (WNV) and Zika virus (ZIKV). The survey concluded that there were no known breeding populations of Ae. aegypti in Delaware, and no WNV- or ZIKV-positive pools were detected among pools of mosquitoes of the aforementioned species.

GGC Repeat Expansion and Exon 1 Methylation of XYLT1 Is a Common Pathogenic Variant in Baratela-Scott Syndrome.

Baratela-Scott syndrome (BSS) is a rare, autosomal-recessive disorder characterized by short stature, facial dysmorphisms, developmental delay, and skeletal dysplasia caused by pathogenic variants in XYLT1. We report clinical and molecular investigation of 10 families (12 individuals) with BSS. Standard sequencing methods identified biallelic pathogenic variants in XYLT1 in only two families. Of the remaining cohort, two probands had no variants and six probands had only a single variant, including four with a heterozygous 3.1 Mb 16p13 deletion encompassing XYLT1 and two with a heterozygous truncating variant. Bisulfite sequencing revealed aberrant hypermethylation in exon 1 of XYLT1, always in trans with the sequence variant or deletion when present; both alleles were methylated in those with no identified variant. Expression of the methylated XYLT1 allele was severely reduced in fibroblasts from two probands. Southern blot studies combined with repeat expansion analysis of genome sequence data showed that the hypermethylation is associated with expansion of a GGC repeat in the XYLT1 promoter region that is not present in the reference genome, confirming that BSS is a trinucleotide repeat expansion disorder. The hypermethylated allele accounts for 50% of disease alleles in our cohort and is not present in 130 control subjects. Our study highlights the importance of investigating non-sequence-based alterations, including epigenetic changes, to identify the missing heritability in genetic disorders.

Paternal uniparental disomy with segmental loss of heterozygosity of chromosome 11 are hallmark characteristics of syndromic and sporadic embryonal rhabdomyosarcoma.

Costello syndrome (CS) arises from a typically paternally derived germline mutation in the proto-oncogene HRAS, and is considered a rasopathy. CS results in failure-to-thrive, intellectual disabilities, short stature, coarse facial features, skeletal abnormalities, congenital heart disease, and a predisposition for cancer, most commonly embryonal rhabdomyosarcoma (ERMS). The goal of this study was to characterize CS ERMS at the molecular level and to determine how divergent it is from sporadic ERMS. We characterized eleven ERMS tumors from eight unrelated CS patients, carrying paternally derived HRAS c.34G>A (p.Gly12Ser; 6) or c.35G>C (p.Gly12Ala; 2) mutations. Loss of heterozygosity (LOH) was evaluated in all CS ERMS by microarray and/or short tandem repeat (STR) markers spanning the entire chromosome 11. Eight CS ERMS tumors displayed complete paternal uniparental disomy of chromosome 11 (pUPD11), whereas two displayed UPD only at 11p and a second primary ERMS tumor showed UPD limited to 11p15.5, the classical hallmark for ERMS. Three sporadic ERMS cell lines (RD, Rh36, Rh18) and eight formalin fixed paraffin embedded (FFPE) ERMS tumors were also analyzed for RAS mutations and LOH status. We found a higher than anticipated frequency of RAS mutations (HRAS or NRAS; 50%) in sporadic ERMS cell lines/tumors. Unexpectedly, complete uniparental disomy (UPD11) was observed in five specimens, while the other six showed LOH extending across the p and q arms of chromosome 11. In this study, we are able to clearly demonstrate complete UPD11 in both syndromic and sporadic ERMS. © 2016 Wiley Periodicals, Inc.

Diamond-Blackfan anemia with mandibulofacial dystostosis is heterogeneous, including the novel DBA genes TSR2 and RPS28.

Patients with physical findings suggestive of Treacher Collins syndrome (TCS) or mandibulofacial dysostosis (MFD) and macrocytic anemia diagnostic of Diamond-Blackfan anemia (DBA) have been reported. Disease-causing genes have been identified for TCS and other MFDs. Mutations in several ribosomal protein genes and the transcription factor GATA1 result in DBA. However, no disease-causing mutation had been identified in the reported patients with the combination of TCS/MFD and DBA phenotype, and we hypothesized that pathogenic mutations in a single gene could be identified using whole exome analysis. We studied probands from six unrelated families. Combining exome analysis and Sanger sequencing, we identified likely pathogenic mutations in 5/6 families. Two mutations in unrelated families were seen in RPS26, the known DBA10 gene. One variant was predicted to affect mRNA splicing, and the other to lead to protein truncation. In another family a likely pathogenic X-linked mutation affecting a highly conserved residue was found in TSR2, which encodes a direct binding partner of RPS26. De novo mutations affecting the RPS28 start codon were found in two unrelated probands, identifying RPS28 as a novel disease gene. We conclude that the phenotype combining features of TCS with DBA is genetically heterogeneous. Each of the pathogenic variants identified is predicted to impede ribosome biogenesis, which in turn could result in altered cell growth and proliferation, causing abnormal embryologic development, defective erythropoiesis and reduced growth. The phenotype combining TCS/MFD and DBA is highly variable, overlaps with DBA and lies within the phenotypic spectrum of ribosomopathies. © 2014 Wiley Periodicals, Inc.