Test ID: LRBA    
Lipopolysaccharide-Responsive Beige-Like Anchor Protein (LRBA) Deficiency, Blood

Aids in the diagnosis of lipopolysaccharide-responsive beige-like anchor protein (LRBA) deficiency

This test is not useful for identifying a carrier status for LRBA deficiency.

The human lipopolysaccharide-responsive beige-like anchor protein (LRBA) gene is on chromosome 4.

Assessment of 109 patients with LRBA deficiency has shown 93 homozygous and 16 compound heterozygous alterations in the gene.

Alterations in the LRBA gene have been observed throughout the length of the gene and include the following main categories: Nonsense; missense; insertions, deletions, indels, and splice site alterations.

The test determines the percentage and intensity of expression of lipopolysaccharide-responsive beige-like anchor (LRBA) protein on T cells and B cells in the peripheral blood.

It can be used as a screening step prior to genetic testing for LRBA; to confirm the finding of an established pathogenic alteration in LRBA at the protein level; and to examine the effect of reported genetic variants of undetermined significance (VUS) on LRBA protein expression.

It can help distinguish LRBA deficiency from conditions with overlapping clinical manifestations, including immune dysregulation and autoimmunity, such as immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX)-like syndromes; early onset hypogammaglobulinemia; common variable immune deficiency (CVID); inflammatory bowel disease (IBD); and autoimmune lymphoproliferative syndrome (ALPS).

Flow Cytometry