Biomaterial Database

Identification of a novel point mutation (Leu72Pro) in the NADH-cytochrome b5 reductase gene of a patient with hereditary methaemoglobinaemia type I. 1998

Y S Wu, and C H Huang, and Y Wan, and Q J Huang, and Z Y Zhu

Centre for Medical Laboratory, Fuzhou General Hospital, People's Republic of China.

Utilizing polymerase chain reaction (PCR) related technology, we investigated the b5R gene of a Chinese patient with hereditary methaemoglobinaemia type I and found a novel missense mutation (CTC-CCC) at codon 72 in exon 3 of the gene. As the mutation generates an Apa I recognition site, homozygosity for the mutation was confirmed by restriction analysis of PCR-amplified fragments from the patient's genomic DNA. We predicted that the residue replacement of Leu with Pro of the mutant enzyme would account for the b5R deficiency in the patient. The results further confirm the genetic polymorphism of b5R gene mutations found in the RCM type I.

UI	MeSH Term	Description	Entries
D008708	Methemoglobinemia	The presence of methemoglobin in the blood, resulting in cyanosis. A small amount of methemoglobin is present in the blood normally, but injury or toxic agents convert a larger proportion of hemoglobin into methemoglobin, which does not function reversibly as an oxygen carrier. Methemoglobinemia may be due to a defect in the enzyme NADH methemoglobin reductase (an autosomal recessive trait) or to an abnormality in hemoglobin M (an autosomal dominant trait). (Dorland, 27th ed)	Methemoglobinemias
D002675	Child, Preschool	A child between the ages of 2 and 5.	Children, Preschool,Preschool Child,Preschool Children
D003579	Cytochrome Reductases		Reductases, Cytochrome
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D016133	Polymerase Chain Reaction	In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.	Anchored PCR,Inverse PCR,Nested PCR,PCR,Anchored Polymerase Chain Reaction,Inverse Polymerase Chain Reaction,Nested Polymerase Chain Reaction,PCR, Anchored,PCR, Inverse,PCR, Nested,Polymerase Chain Reactions,Reaction, Polymerase Chain,Reactions, Polymerase Chain
D017354	Point Mutation	A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.	Mutation, Point,Mutations, Point,Point Mutations
D042966	Cytochrome-B(5) Reductase	A FLAVOPROTEIN oxidoreductase that occurs both as a soluble enzyme and a membrane-bound enzyme due to ALTERNATIVE SPLICING of a single mRNA. The soluble form is present mainly in ERYTHROCYTES and is involved in the reduction of METHEMOGLOBIN. The membrane-bound form of the enzyme is found primarily in the ENDOPLASMIC RETICULUM and outer mitochondrial membrane, where it participates in the desaturation of FATTY ACIDS; CHOLESTEROL biosynthesis and drug metabolism. A deficiency in the enzyme can result in METHEMOGLOBINEMIA.	Methemoglobin Reductase,NADH Cytochrome B5 Reductase,NADH Methemoglobin Reductase,NADH-Cytochrome B5 Reductase,NADH-Ferrihemoglobin Reductase,B5 Reductase, NADH-Cytochrome,Methemoglobin Reductase, NADH,NADH Ferrihemoglobin Reductase,Reductase, Methemoglobin,Reductase, NADH Methemoglobin,Reductase, NADH-Ferrihemoglobin
D018076	DNA, Complementary	Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.	Complementary DNA,cDNA,cDNA Probes,Probes, cDNA