Repeat Disorders
STR: FRA11B
Comment on list classification: Low evidence of clinical relevance of expression of the fragile site.Created: 6 Sep 2021, 7:43 a.m. | Last Modified: 6 Sep 2021, 7:43 a.m.
Panel Version: 0.135
FRA11B is a rare folate sensitive fragile site caused by expansion of (CCG)n in the 5'UTR of CBL, and hypermethylation of adjacent CpG islands. There are commonly 11 repeats. The pre-mutation ranges from 80-100, while >100 leads to expression of the fragile site. Two cases of Jacobsen (llq-) syndrome, which is the clinical presentation of the loss of part of the long arm of chromosome 11, have been associated with the FRA11B repeat expansion (expected breakpoint). The estimated prevalence of the FRA11B expansion is 1 in 5,000, which the estimated prevalence of Jacobsen syndrome is <1 in 100,000.
Sources: LiteratureCreated: 6 Sep 2021, 7:41 a.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes
Jacobsen syndrome MIM#147791
Publications
Str: fra11b has been classified as Red List (Low Evidence).
Tag paediatric-onset tag was added to STR: FRA11B.
Str: fra11b has been classified as Red List (Low Evidence).
STR: FRA11B was added STR: FRA11B was added to Repeat Disorders. Sources: Literature Mode of inheritance for STR: FRA11B was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for STR: FRA11B were set to 7881408; 7603564; 9508241; 9927483; 10767345; 11076037; 19267933 Phenotypes for STR: FRA11B were set to Jacobsen syndrome MIM#147791 Review for STR: FRA11B was set to AMBER