Recessive hereditary methemoglobinemia: two novel mutations in the NADH-cytochrome b5 reductase gene.
We report the clinical and molecular characteristics of 6 new patients with recessive hereditary methemoglobinemia due to cytochrome b5 reductase deficiency. One patient was affected by Type-II disease with cyanosis and severe progressive neurological dysfunction, whereas the others displayed the benign Type-I phenotype. Methemoglobin levels ranged from 12.1% to 26.2% and cytochrome b5 reductase activity from 0 to 10% of normal. Eight different mutations were detected among the twelve mutated alleles identified, one splicing mutation, two stop codon, and five missense. Two mutations c. 82 C>T(Gln27STOP) and c. 136 C>T(Arg45Trp) are new. Prenatal diagnosis was performed in the family with Type-II disease.
Fermo
Elisa
E
U.O. Ematologia 2, Fondazione IRCCS Ospedale Maggiore, Mangiagalli e Regina Elena, Via F. Sforza, 35, 20122 Milano, Italy.
Bianchi
Paola
P
Vercellati
Cristina
C
Marcello
Anna Paola
AP
Garatti
Massimo
M
Marangoni
Ornella
O
Barcellini
Wilma
W
Zanella
Alberto
A
D000483:Alleles; D042966:Cytochrome-B(5) Reductase / Q000032:analysis* / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D005808:Genes, Recessive; D006801:Humans; D007223:Infant; D008297:Male; D008706:Methemoglobin / Q000032:analysis*; D008708:Methemoglobinemia / Q000201:enzymology / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D016415:Sequence Alignment
D008706:Methemoglobin; D042966:Cytochrome-B(5) Reductase