Allele-specific epigenome maps reveal sequence-dependent stochastic switching at regulatory loci

To assess the impact of genetic variation in regulatory loci on human health, we constructed a high-resolution map of allelic imbalances in DNA methylation, histone marks, and gene transcription in 71 epigenomes from 36 distinct cell and tissue types from 13 donors. Deep whole-genome bisulfite sequencing of 49 methylomes revealed sequence-dependent CpG methylation imbalances at thousands of heterozygous regulatory loci. Such loci are enriched for stochastic switching, which is defined as random transitions between fully methylated and unmethylated states of DNA. The methylation imbalances at thousands of loci are explainable by different relative frequencies of the methylated and unmethylated states for the two alleles. Further analyses provided a unifying model that links sequence-dependent allelic imbalances of the epigenome, stochastic switching at gene regulatory loci, and disease-associated genetic variation.

Use of radiotelemetry to obtain expressive language samples

Expressive language samples were obtained from normal and language-disordered children through standard interview procedures and through wireless radiotelemetry. Comparisons of these samples using Developmental Sentence Scoring (DSS), mean length of utterance (MLU), and inflectional scoring indicated significant differences between the groups of children, and among the interview-telemetry samples. Telemetry samples yielded different overall scores from those obtained with the interview samples, and there were significant differences in the types of language performance within the samples. Reliable telemetry scores across days were obtained. Difficulties in using the equipment are described and the procedures are compared.