Omenn Syndrome in an Infant: A Case Report

Background: Primary immunodeficiency disorders are considered in scenarios of recurrent infections with early onset, in an optimally nourished infant. Omenn syndrome, an autosomal recessive, rare type of severe combined immunodeficiency disorder, has been reported with varied clinical manifestations. Here, we report an infant suspected of congenital immunodeficiency whose genetic analysis revealed Omenn syndrome, without manifesting all the typical phenotypic features of this condition.

Clinical Description: A five-months old female infant, born out of consanguineous marriage, presented with recurrent episodes of respiratory distress requiring multiple hospitalizations. She subsequently developed persistent diarrhea, extensive perianal and gluteal dermatitis, respiratory worsening with fulminant septicemic shock.

Management: Supportive treatment with intravenous fluids, mechanical ventilation, antibiotics, inotropes were started. A hypoallergenic diet was also administered by naso-gastric route. Considering a background of consanguinity, early age of onset and recurrent symptoms with an acutely worsening clinical course, a genetic work up sent for primary immunodeficiency. It showed a contiguous deletion spanning genomic location encompassing DCLRE1C gene in chromosome 10 was detected, suggestive of a likely pathogenic variant of Omenn syndrome. Despite all measures, the infant succumbed to the disease.

Conclusion: By reporting this case, we intend to highlight that genetic evaluation for primary immunodeficiency may reveal some disorders whose classical phenotype may not always be present in the patient under evaluation. This is yet another atypical case of Omenn syndrome.