Rare Daily Staff

Researchers at Yale School of Medicine reported that they have discovered the underlying genetic cause of a rare childhood disorder that mimics inflammatory bowel disease, a finding that may help understanding of other inflammatory and autoimmune disorders.

The findings emerged from the case of a young boy with a mysterious illness at Yale New Haven Hospital. The boy suffered from abdominal pain, intermittent bouts of fever, and diarrhea over multiple days, as well as canker sores in his mouth.

Genome sequencing of the child and his healthy parents revealed that the boy had a genetic defect that blocked ELF4, a transcription factor on the X chromosome that regulates expression of a large number of other genes. By reaching out to colleagues in the field, the research team identified two other male children with similar symptoms who also had ELF4 gene variants.

The disorder is now termed Deficiency in ELF4, X-linked (DEX). More cases are now being identified.

“It is very exciting to start with patients who are sick and discover an unexpected new gene with a fundamental role in regulating inflammation.” said Carrie Lucas, an assistant professor of immunobiology at Yale School of Medicine and senior author of the paper published in the journal Nature Immunology.

According to the researchers, the symptoms experienced by the children in the study were similar to those associated with other inflammatory bowel diseases, including ulcerative colitis and Crohn’s Disease, thought to be caused by an overactive immune system response that damages tissues of the host.

After identifying the ELF4 variant, Lucas’s lab then studied its effects in cultured cells from patients, as well as in mice using CRISPR gene-editing to introduce patient-derived ELF4 mutations. They confirmed that the variant disrupted ELF4 function, and resulted in elevated inflammatory responses of a variety of immune cell types.

The widespread effects of the variant suggest ELF4 and its target genes likely play a role in regulating inflammation in multiple diseases, Lucas said.

“This gives us the opportunity to identify and study the effects not only of ELF4 but also the genes it regulates across immune cell types and inflammatory disease phenotypes,” she said. “This will help us create a new molecular roadmap relevant to understanding and treating human disease.”

Photo: Carrie Lucas, assistant professor of immunobiology at Yale School of Medicine

X