Gene: [22q133/DIA1] diaphorase 1 (NADH) (cytochrome b-5 reductase); methemoglobinemia (cytochrome b-5 reductase deficiency);
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GEN |
[1] The gene length is 30.5 kb. Exons: 9 (21, 132, 73, 107, 130, 84,
86, 100, and 171 bp); introns: 8 (12238, 5235, 382, 2580, 458, 212,
3384, and 3792 bp). All of them meet the <5'-GT..AG-3'> frame
criterion (Sharp PA: Cell, 23, 643-646, 1981); they are characterized
by a high content of Alu-repeats, 17 complete and 12 incomplete ones
(e.g., there are nine repeats in intron 1, four of them forming a
tandem); deletions up to 1.5 kb in length are frequent in this region.
[2] The 5'-nts region, about 0.5 kb in length, does not contain the canonical TATA and CCAAT promoters, however, it is rich in GGGCGG regions, which are probably binding sites for transcriptional factor Sp1 (Gidoni &: Nature, 312, 409-413, 1984); in addition, this region fits the criterion of Bird (Bird &: Nature, 321, 209-213, 1986) for a |
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FAG |
[1] Biochemical genetic studies revealed four diaphorase isoforms; all
are registered in MIM Catalogue: DIA1 (MIM:250800), DIA2 (MIM:125870),
DIA3 (MIM:125880), and DIA4 (MIM:125860).
[2] Only two genes have been mapped definitely and included in HGM. These are DIA1 (GEM:22q133/DIA1) and DIA4 (GEM:16q221/NMOR1); both have been designated in HGM as 'cytochrome b5 reductase'. Attempts to map DIA2 (GEM:00.0/DIA2) did not give conclusive results." |
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PAT |
At least two types of cytochrome b5 reductase deficiency are distinguished: the erythrocytic one (type I, the DIA1 deficiency occurs in red blood cells only) and the generalized type (type II). In clinically more severe type II, the DIA1 deficiency is found in many cells besides red blood cells and is accompanied by mental retardation and neurological disturbances." |
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REF |
CLO,LOC,MOL "Bull PC &: Ann Hum Genet, 52, (Part 4), 263-268, 1988 LOC,CYG "Fisher RA &: Ann Hum Genet, 41, 151-155, 1977 REV,PAT "Gibson QH: Am J Hematol, 42, 3-6, 1993 LOC,CYG "Hors-Cayla MC &: Hum Genet, 58, 140-143, 1981 MAP "Julier C &: AJHG, 42, 297-308, 1988 PND "Junien C &: Prenatal Diag, 1, 17-24, 1981 LOC,CYG "Junien C &: Hum Genet, 42, 233-239, 1978 PND "Kaftory A &: Isr J Med Sci, 22, 837-840, 1986 MUT,PAT "Katsube T &: AJHG, 48, 799-808, 1991 MUT,PAT "Kobayashi Y &: Blood, 75, 1408-1413, 1990 MUT,PAT "Shirabe K &: AJHG, 57, 302-310, 1995 MUT,PAT "Shirabe K &: JBC, 269, 5952-5957, 1994 GEN,SEQ,EXP "Tomatsu S &: Gene, 80, 353-361, 1989 MUT,PAT "Vieira LM &: Blood, 85, 2254-2262, 1995 CLO,SEQ,PAT "Yubisui T &: PNAS, 84, N11, 3609-3613, 1987 SEQ,MOP,PEP "Yubisui T &: J Biochem, 99, 407-422, 1986 SEQ,MOP,PEP "Yubisui T &: J Biochem, 96, 579-582, 1984 |
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KEY |
hem, xen, lip |
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CLA |
coding, basic |
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LOC |
22 q13.3 |
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MIM |
MIM: 250800 |
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EZN |
ENZYME: 1.6.2.2 |
