👤 Eric C Wooten

Encephalocraniocutaneous lipomatosis (ECCL) is a rare somatic disorder caused by mutations in various genes of the RAS-MAPK pathway. Distinctive features of ECCL include nevus psiloliparus, scalp alopecia, ocular choristomas, and intracranial lipomas. ECCL is most commonly associated with FGFR1 and KRAS mutations. An NRAS variant causing ECCL has only been reported in the literature once. We present the case of a female infant with ECCL, harboring an NRAS somatic mutation, variant c.37G>C (p.Gly13Arg). This is the second reported case of an NRAS variant in ECCL and the first to document an associated intracranial lipoma. The report highlights the genotypic, clinical, and neuroradiological presentation of ECCL, its overlap and distinctions with other mosaic RASopathies, and reviews the recommended diagnostic approach when ECCL is suspected. Show less

Bicuspid Aortic Valve (BAV) is a highly heritable congenital heart defect. The low frequency of BAV (1% of general population) limits our ability to perform genome-wide association studies. We present the application of four a priori SNP selection techniques, reducing the multiple-testing penalty by restricting analysis to SNPs relevant to BAV in a genome-wide SNP dataset from a cohort of 68 BAV probands and 830 control subjects. Two knowledge-based approaches, CANDID and STRING, were used to systematically identify BAV genes, and their SNPs, from the published literature, microarray expression studies and a genome scan. We additionally tested Functionally Interpolating SNPs (fitSNPs) present on the array; the fourth consisted of SNPs selected by Random Forests, a machine learning approach. These approaches reduced the multiple testing penalty by lowering the fraction of the genome probed to 0.19% of the total, while increasing the likelihood of studying SNPs within relevant BAV genes and pathways. Three loci were identified by CANDID, STRING, and fitSNPS. A haplotype within the AXIN1-PDIA2 locus (p-value of 2.926x10(-06)) and a haplotype within the Endoglin gene (p-value of 5.881x10(-04)) were found to be strongly associated with BAV. The Random Forests approach identified a SNP on chromosome 3 in association with BAV (p-value 5.061x10(-06)). The results presented here support an important role for genetic variants in BAV and provide support for additional studies in well-powered cohorts. Further, these studies demonstrate that leveraging existing expression and genomic data in the context of GWAS studies can identify biologically relevant genes and pathways associated with a congenital heart defect. Show less