A novel L218P mutation in NADH-cytochrome b5 reductase associated with type I recessive congenital methemoglobinemia.
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.
Arikoglu
Tugba
T
Department of Pediatric Hematology, Dr. Sami Ulus Children's Health Education and Research Hospital, Ankara, Turkey.
Yarali
Nese
N
Kara
Abdurrahman
A
Bay
Ali
A
Bozkaya
Ikbal O
IO
Tunc
Bahattin
B
Percy
Melanie J
MJ
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
D014815:Vitamins; D008706:Methemoglobin; D042966:Cytochrome-B(5) Reductase; D001205:Ascorbic Acid