title: 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: Department of Pediatric Hematology, Dr. Sami Ulus Children's Health Education and Research Hospital, Ankara, Turkey.
authors: Tugba
authors: T
authors: Arikoglu
authors: Nese
authors: N
authors: Yarali
authors: Abdurrahman
authors: A
authors: Kara
authors: Ali
authors: A
authors: Bay
authors: Ikbal O
authors: IO
authors: Bozkaya
authors: Bahattin
authors: B
authors: Tunc
authors: Melanie J
authors: MJ
authors: Percy
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D001205:Ascorbic Acid / Q000627:therapeutic use; D002648:Child; D003490:Cyanosis / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D042966:Cytochrome-B(5) Reductase / Q000235:genetics*; D005808:Genes, Recessive; D006801:Humans; D008297:Male; D008706:Methemoglobin / Q000032:analysis; D008708:Methemoglobinemia / Q000151:congenital / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics*; D009154:Mutation / Q000235:genetics; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D014815:Vitamins; D008706:Methemoglobin; D042966:Cytochrome-B(5) Reductase; D001205:Ascorbic Acid