title: Mutations in the 5' UTR of ANKRD26, the ankirin repeat domain 26 gene, cause an autosomal-dominant form of inherited thrombocytopenia, THC2.
abstract: THC2, an autosomal-dominant thrombocytopenia described so far in only two families, has been ascribed to mutations in MASTL or ACBD5. Here, we show that ANKRD26, another gene within the THC2 locus, and neither MASTL nor ACBD5, is mutated in eight unrelated families. ANKRD26 was also found to be mutated in the family previously reported to have an ACBD5 mutation. We identified six different ANKRD26 mutations, which were clustered in a highly conserved 19 bp sequence located in the 5' untranslated region. Mutations were not detected in 500 controls and are absent from the 1000 Genomes database. Available data from an animal model and Dr. Watson's genome give evidence against haploinsufficiency as the pathogenetic mechanism for ANKRD26-mediated thrombocytopenia. The luciferase reporter assay suggests that these 5' UTR mutations might enhance ANKRD26 expression. ANKRD26 is the ancestor of a family of primate-specific genes termed POTE, which have been recently identified as a family of proapoptotic proteins. Dysregulation of apoptosis might therefore be the pathogenetic mechanism, as demonstrated for another thrombocytopenia, THC4. Further investigation is needed to provide evidence supporting this hypothesis.
authors.affiliation: Medical Genetics Unit, Department of Gynaecological, Obstetric, and Paediatric Sciences, University of Bologna, Bologna 40138, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Pippucci
authors.forename: Anna
authors.initials: A
authors.lastname: Savoia
authors.forename: Silverio
authors.initials: S
authors.lastname: Perrotta
authors.forename: Núria
authors.initials: N
authors.lastname: Pujol-Moix
authors.forename: Patrizia
authors.initials: P
authors.lastname: Noris
authors.forename: Giovanni
authors.initials: G
authors.lastname: Castegnaro
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pecci
authors.forename: Chiara
authors.initials: C
authors.lastname: Gnan
authors.forename: Francesca
authors.initials: F
authors.lastname: Punzo
authors.forename: Caterina
authors.initials: C
authors.lastname: Marconi
authors.forename: Samuele
authors.initials: S
authors.lastname: Gherardi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Loffredo
authors.forename: Daniela
authors.initials: D
authors.lastname: De Rocco
authors.forename: Saverio
authors.initials: S
authors.lastname: Scianguetta
authors.forename: Serena
authors.initials: S
authors.lastname: Barozzi
authors.forename: Pamela
authors.initials: P
authors.lastname: Magini
authors.forename: Valeria
authors.initials: V
authors.lastname: Bozzi
authors.forename: Luca
authors.initials: L
authors.lastname: Dezzani
authors.forename: Mariateresa
authors.initials: M
authors.lastname: Di Stazio
authors.forename: Marcella
authors.initials: M
authors.lastname: Ferraro
authors.forename: Giovanni
authors.initials: G
authors.lastname: Perini
authors.forename: Marco
authors.initials: M
authors.lastname: Seri
authors.forename: Carlo L
authors.initials: CL
authors.lastname: Balduini
mesh_terms: D017089:Ankyrin Repeat / Q000235:genetics*; D001483:Base Sequence; D019457:Chromosome Breakage; D025063:Chromosome Disorders / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D005260:Female; D005799:Genes, Dominant; D056426:Genetic Loci; D057895:Haploinsufficiency; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D013921:Thrombocytopenia / Q000151:congenital / Q000235:genetics