Publications by authors named "J Britt Ravnan"
Article Synopsis
- Uniparental disomy (UPD) involves the inheritance of both copies of a chromosome from one parent, which can lead to abnormal gene expression and various health issues depending on whether the chromosome is from the mother or father.
- UPD(14)pat is associated with severe features like skeletal anomalies and poor survival due to overexpression of the paternally expressed gene RTL1, while UPD(14)mat presents milder symptoms like growth failure because of the absence of the paternally expressed DLK1 gene.
- Recent studies involving six individuals with variations in the imprinted 14q32 region suggest that different gene deletions and duplications can result in UPD-like phenotypes, emphasizing the importance of gene dosage in
Background: While microarray testing can identify chromosomal abnormalities missed by karyotyping, its prenatal use is often avoided in low-risk pregnancies due to the possible identification of variants of uncertain significance (VOUS).
Methods: We tested 2,970 prenatal samples of all referral indications using a rapid BACs-on-Beads-based assay with probes for sex chromosomes, common autosomal aneuploidies, and 20 microdeletion/microduplication syndromes, designed as an alternative to microarray in low-risk pregnancies and an alternative to rapid aneuploidy testing in pregnancies also undergoing microarray analysis.
Results: Interpretable results were obtained in 2,940 cases (99.
We describe the molecular and clinical characterization of nine individuals with recurrent, 3.4-Mb, de novo deletions of 3q13.2-q13.
View Article and Find Full Text PDFObjective: To test the hypothesis that chromosomal microarray analysis frequently diagnoses conditions that require specific medical follow-up and that referring physicians respond appropriately to abnormal test results.
Methods: A total of 46,298 postnatal patients were tested by chromosomal microarray analysis for a variety of indications, most commonly intellectual disability/developmental delay, congenital anomalies, dysmorphic features, and neurobehavioral problems. The frequency of detection of abnormalities associated with actionable clinical features was tallied, and the rate of physician response to a subset of abnormal tests results was monitored.
Objective: To demonstrate the usefulness of microarray testing in prenatal diagnosis based on our laboratory experience.
Methods: Prenatal samples received from 2004 to 2011 for a variety of indications (n = 5003) were tested using comparative genomic hybridization-based microarrays targeted to known chromosomal syndromes with later versions of the microarrays providing backbone coverage of the entire genome.
Results: The overall detection rate of clinically significant copy number alterations (CNAs) among unbiased, nondemise cases was 5.