Isolation and characterisation of GTF2IRD2, a novel fusion gene and member of the TFII-I family of transcription factors, deleted in Williams-Beuren syndrome.
Williams-Beuren syndrome (WBS) is a developmental disorder with characteristic physical, cognitive and behavioural traits caused by a microdeletion of approximately 1.5 Mb on chromosome 7q11.23. In total, 24 genes have been described within the deleted region to date. We have isolated and characterised a novel human gene, GTF2IRD2, mapping to the WBS critical region thought to harbour genes important for the cognitive aspects of the disorder. GTF2IRD2 is the third member of the novel TFII-I family of genes clustered on 7q11.23. The GTF2IRD2 protein contains two putative helix-loop-helix regions (I-repeats) and an unusual C-terminal CHARLIE8 transposon-like domain, thought to have arisen as a consequence of the random insertion of a transposable element generating a functional fusion gene. The retention of a number of conserved transposase-associated motifs within the protein suggests that the CHARLIE8-like region may still have some degree of transposase functionality that could influence the stability of the region in a mechanism similar to that proposed for Charcot-Marie-Tooth neuropathy type 1A. GTF2IRD2 is highly conserved in mammals and the mouse ortholgue (Gtf2ird2) has also been isolated and maps to the syntenic WBS region on mouse chromosome 5G. Deletion mapping studies using somatic cell hybrids show that some WBS patients are hemizygous for this gene, suggesting that it could play a role in the pathogenesis of the disorder.
Tipney
Hannah J
HJ
University of Manchester, Academic Unit of Medical Genetics and Regional Genetic Service, St Mary's Hospital, Manchester, UK.
Hinsley
Timothy A
TA
Brass
Andrew
A
Metcalfe
Kay
K
Donnai
Dian
D
Tassabehji
May
M
D000595:Amino Acid Sequence; D000818:Animals; D019677:Artificial Gene Fusion; D001483:Base Sequence; D002874:Chromosome Mapping; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D020440:Gene Duplication; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000235:genetics* / Q000378:metabolism; D019474:Transcription Factors, TFIII; D014158:Transcription, Genetic; D018980:Williams Syndrome / Q000235:genetics*
D004268:DNA-Binding Proteins; C496282:GTF2IRD2 protein, human; C486558:Gtf2ird1 protein, mouse; D009124:Muscle Proteins; D009687:Nuclear Proteins; D015534:Trans-Activators; D019473:Transcription Factors, TFII; D019474:Transcription Factors, TFIII