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A case report of autosomal recessive methemoglobinemia in a child

Year: 2026

Type: article

Abstract: ) state, leading to elevated methemoglobin (MetHb) levels and cyanosis. We report the case of a 3-year-old female with a history of congenital cyanotic heart disease who presented with worsening cyanosis and was found to have a MetHb level of 49.3%. She responded initially to methylene blue therapy, but levels fluctuated over the following week. Whole-exome sequencing revealed a homozygous missense variant in the cytochrome b5 (CytB5) reductase 3 gene, consistent with autosomal recessive methemoglobinemia due to CytB5 reductase deficiency. The identified variant has not been previously reported and was classified as a variant of uncertain significance. This case underscores the importance of considering hereditary methemoglobinemia in children with unexplained cyanosis and persistent MetHb elevation. Genetic evaluation remains essential in suspected hereditary cases to inform prognosis, guide long-term care, and support family counseling.

Source: Turkish Journal of Emergency Medicine

DOI: 10.4103/tjem.tjem_16_26

Authors: Aline Khalil, Duaa AL Lawati, Patcha Yenjabog, Ziad Kazzi, Tharwat EL Zahran

Institutions: American University of Beirut Medical Center, Emory University, Khoula Hospital, Ministry of Health, Navamindradhiraj University, Vajira Hospital

Language: English

Topic: Methemoglobinemia and Tumor Lysis Syndrome

Subfield: Hematology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: diamond

OpenAlex ID: W7221309778

FWCI:

Cites: 13

Cited by:

Related to: 10