학술논문

Hyper-IgE Syndrome due to an Elusive Novel Intronic Homozygous Variant in DOCK8.
Document Type
Article
Source
Journal of Clinical Immunology. Jan2022, Vol. 42 Issue 1, p119-129. 11p.
Subject
*JOB'S syndrome
*GUANINE nucleotide exchange factors
*ECZEMA
*NUCLEOTIDE sequencing
*HEMATOPOIETIC stem cells
*STEM cell transplantation
Language
ISSN
0271-9142
Abstract
Rare, biallelic loss-of-function mutations in DOCK8 result in a combined immune deficiency characterized by severe and recurrent cutaneous infections, eczema, allergies, and susceptibility to malignancy, as well as impaired humoral and cellular immunity and hyper-IgE. The advent of next-generation sequencing technologies has enabled the rapid molecular diagnosis of rare monogenic diseases, including inborn errors of immunity. These advances have resulted in the implementation of gene-guided treatments, such as hematopoietic stem cell transplant for DOCK8 deficiency. However, putative disease-causing variants revealed by next-generation sequencing need rigorous validation to demonstrate pathogenicity. Here, we report the eventual diagnosis of DOCK8 deficiency in a consanguineous family due to a novel homozygous intronic deletion variant that caused aberrant exon splicing and subsequent loss of expression of DOCK8 protein. Remarkably, the causative variant was not initially detected by clinical whole-genome sequencing but was subsequently identified and validated by combining advanced genomic analysis, RNA-seq, and flow cytometry. This case highlights the need to adopt multipronged confirmatory approaches to definitively solve complex genetic cases that result from variants outside protein-coding exons and conventional splice sites. [ABSTRACT FROM AUTHOR]