A splicing mutation in the cytochrome b5 gene from a patient with congenital methemoglobinemia and pseudohermaphrodism.
We have analyzed reticulocyte and leukocyte mRNAs isolated from a patient with congenital methemoglobinemia and pseudohermaphrodism. The cytochrome b5 cDNA sequences were amplified using specific oligonucleotide primers and the polymerase chain reaction (PCR). DNA sequencing indicated that there was a 16-bp deletion in the cDNA leading to a new, in-frame stop signal and resulting in a truncated protein of 45 amino acids. Genomic DNA was analyzed, and the molecular lesion was shown to be an AG-->GG alteration in the 3' splicing junction of intron 1. The splice site alteration leads to the usage of the nearest AG as an alternative splice site, resulting in a 16-bp deletion in the mRNA. All of the studies on reticulocyte mRNA and genomic DNA indicated that the patient was homozygous for the lesion.
Giordano
S J
SJ
Department of Biochemistry and Molecular Pathology, Northeastern Ohio Universities College of Medicine, Rootstown 44272.
Kaftory
A
A
Steggles
A W
AW
D001483:Base Sequence; D015786:Cytochromes b5 / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D004274:DNA, Recombinant; D012734:Disorders of Sex Development / Q000201:enzymology* / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D008708:Methemoglobinemia / Q000151:congenital* / Q000201:enzymology*; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012156:Reticulocytes / Q000378:metabolism
D017931:DNA Primers; D004274:DNA, Recombinant; D012333:RNA, Messenger; D015786:Cytochromes b5