LPS-responsive beige-like anchor (LRBA) gene mutation in a family with inflammatory bowel disease and combined immunodeficiency.
BACKGROUND
Clinical immunology has traditionally relied on accurate phenotyping of the patient's immune dysfunction for the identification of a candidate gene or genes for sequencing and molecular confirmation. Although this is also true for other branches of medicine, the marked variability in immune-related phenotypes and the highly complex network of molecules that confer normal host immunity are challenges that clinical immunologists often face in their quest to establish a specific genetic diagnosis.


OBJECTIVE
We sought to identify the underlying genetic cause in a consanguineous family with chronic inflammatory bowel disease-like disorder and combined immunodeficiency.


METHODS
We performed exome sequencing followed by autozygome filtration.


RESULTS
A truncating mutation in LPS-responsive beige-like anchor (LRBA), which abolished protein expression, was identified as the most likely candidate variant in this family.


CONCLUSIONS
The combined exome sequencing and autozygosity mapping approach is a powerful tool in the study of atypical immune dysfunctions. We identify LRBA as a novel immunodeficiency candidate gene the precise role of which in the immune system requires future studies.
Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia.
Abdullah
A
Alangari
Abdulrahman
A
Alsultan
Nouran
N
Adly
Michel J
MJ
Massaad
Iram Shakir
IS
Kiani
Abdulrahman
A
Aljebreen
Emad
E
Raddaoui
Abdul-Kareem
AK
Almomen
Saleh
S
Al-Muhsen
Raif S
RS
Geha
Fowzan S
FS
Alkuraya
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics*; D000293:Adolescent; D001483:Base Sequence; D002648:Child; D003241:Consanguinity; D004252:DNA Mutational Analysis; D059472:Exome / Q000235:genetics* / Q000276:immunology; D005190:Family; D006801:Humans; D016130:Immunophenotyping; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000235:genetics* / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D016511:Severe Combined Immunodeficiency / Q000150:complications / Q000235:genetics* / Q000276:immunology; D055815:Young Adult
D048868:Adaptor Proteins, Signal Transducing; D008070:Lipopolysaccharides; C428703:LRBA protein, human