Detection and reporting of homozygosity associated with consanguinity in the clinical laboratory.

The detection of consanguinity by the presence of multiple regions of homozygosity (ROH) is not an uncommon occurrence in clinical laboratories performing SNP microarray analysis. Reporting practices amongst laboratories are highly variable, due in part to differences in testing platforms, threshold parameters, language utilized, and laboratory policies. While guidance documents have provided a framework for detection and reporting practices, and will doubtless serve to harmonize the field, there are still many facets of the testing that remain at the discretion of the performing laboratory.

Variable approaches to genetic counseling for microarray regions of homozygosity associated with parental relatedness.

SNP microarrays are capable of detecting regions of homozygosity (ROH) which can suggest parental relatedness. This study was designed to describe pre- and post-test counseling practices of genetics professionals regarding ROH, explore perceived comfort and ethical concerns in the follow-up of such results, demonstrate awareness of laws surrounding duty to report consanguinity and incest, and allow respondents to share their personal experiences with results suggesting a parental relationship. A 35 question survey was administered to 240 genetic counselors and geneticists who had ordered or counseled for SNP microarray.

Regions of homozygosity identified by SNP microarray analysis aid in the diagnosis of autosomal recessive disease and incidentally detect parental blood relationships.

Purpose: The purpose of this study was to document the ability of single-nucleotide polymorphism microarray to identify copy-neutral regions of homozygosity, demonstrate clinical utility of regions of homozygosity, and discuss ethical/legal implications when regions of homozygosity are associated with a parental blood relationship.

Methods: Study data were compiled from consecutive samples sent to our clinical laboratory over a 3-year period. A cytogenetics database identified patients with at least two regions of homozygosity >10 Mb on two separate chromosomes.

Variability in laboratory reporting practices for regions of homozygosity indicating parental relatedness as identified by SNP microarray testing.

Purpose: Single-nucleotide polymorphism (SNP) microarrays are capable of detecting regions of homozygosity (ROH) that can suggest parental consanguinity or incest. This study was designed to describe the variable reporting practices of clinical laboratories in the United States regarding ROH found on SNP microarray tests, to discuss the follow-up practices of laboratory personnel when findings of ROH indicate consanguinity or incest, and to highlight the legal and ethical dilemmas faced by workers who have discovered these incidental findings.

Methods: A 20-question survey was administered to microarray experts at 18 laboratories offering clinical SNP microarray tests.

Analysis of Ellis van Creveld syndrome gene products: implications for cardiovascular development and disease.

Mutations identified in a cohort of patients with atrioventricular septal defects as a part of Ellis van Creveld syndrome (EvC syndrome) led us to study the role of two non-homologous genes, EVC and LBN, in heart development and disease pathogenesis. To address the cause of locus heterogeneity resulting in an indistinguishable heart-hand phenotype, we carried out in situ hybridization and immunofluorescence and identified co-localization of Evc and Lbn mRNA and protein. In the heart, expression was identified to be strongest in the secondary heart field, including both the outflow tract and the dorsal mesenchymal protrusion, but was also found in mesenchymal structures of the atrial septum and the atrioventricular cushions.