A novel L218P mutation in NADH-cytochrome b5 reductase associated with type I recessive congenital methemoglobinemia.

Abstract

The presence of central cyanosis that is unrelated to cardiopulmonary causes alerts clinicians to a possible diagnosis of methemoglobinemia. Congenital methemoglobinemia due to deficiency of nicotinamide-adenine dinucleotide (NADH)-cytochrome b5 reductase (cb(5)r) is an autosomal recessive disorder characterized by life long cyanosis. Here we report a six-year old boy who presented with central cyanosis and upon examination revealed a methemoglobin level of 19.0%. Sequencing the CYB5R3 gene identified a homozygous T-->C transition at base c.653, which changed codon 218 from leucine to proline (L218P) in cb(5)r protein. Treatment with ascorbic acid relieved the cyanosis and returned methemoglobin levels to normal.

• Authors: Tugba Arikoglu, Nese Yarali, Abdurrahman Kara, Ali Bay, Ikbal O Bozkaya, Bahattin Tunc, Melanie J Percy
• Journal: Pediatric hematology and oncology (Pediatr Hematol Oncol) 2009 Jul-Aug Vol. 26 Issue 5 Pg. 381-5 ISSN: 1521-0669 [Electronic] England
• PMID: 19579085 (Publication Type: Case Reports, Journal Article)

Chemical References

• Vitamins
• Methemoglobin
• Cytochrome-B(5) Reductase
• Ascorbic Acid

Topics

• Amino Acid Substitution (genetics)
• Ascorbic Acid (therapeutic use)
• Child
• Cyanosis (diagnosis, drug therapy, genetics)
• Cytochrome-B(5) Reductase (genetics)
• Genes, Recessive
• Humans
• Male
• Methemoglobin (analysis)
• Methemoglobinemia (congenital, diagnosis, drug therapy, genetics)
• Mutation (genetics)
• Vitamins (therapeutic use)