title: Identification of a PIG-A related processed gene on chromosome 12.
abstract: PIG-A, the gene encoding the glycoinositol phospholipid anchor synthetic element that is defective in paroxysmal nocturnal hemoglobinuria (PNH), resides on the X chromosome. In the course of analyses of PIG-A genetic alterations in PNH patients, polymerase chain reaction (PCR) amplification of reverse-transcribed RNA from affected leukocytes of a patient with diminished PIG-A mRNA expression yielded a PIG-A related sequence with 126 nucleotide substitutions and five deletions. In the present study, the origin of this product was investigated. Selective reverse transcription (RT)/PCR amplifications with primers specific for PIG-A and this variant sequence, analyses of RNA from unaffected cells, and differential endonuclease digestions showed that mRNA with this sequence is coexpressed with PIG-A mRNA in a wide range of cell types. Mapping of genomic DNA from human/rodent hybrids showed that the sequence derives from a processed gene, designated PIG-A-II, that is encoded on chromosome 12.
authors.affiliation: Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA.
authors.forename: S
authors.initials: S
authors.lastname: Nagarajan
authors.forename: C J
authors.initials: CJ
authors.lastname: Brown
authors.forename: M E
authors.initials: ME
authors.lastname: Medof
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D014644:Genetic Variation; D017261:Glycosylphosphatidylinositols / Q000235:genetics; D006457:Hemoglobinuria, Paroxysmal / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; C080086:phosphatidylinositol glycan-class A protein