title: Severe forms of Baraitser-Winter syndrome are caused by ACTB mutations rather than ACTG1 mutations.
abstract: ACTB and ACTG1 mutations have recently been reported to cause Baraitser-Winter syndrome (BRWS) - a rare condition characterized by ptosis, colobomata, neuronal migration disorder, distinct facial anomalies and intellectual disability. One of the patients carrying an ACTB mutation was previously diagnosed with Fryns-Aftimos syndrome (FAS), which is a rare and severe, multiple congenital anomaly (MCA) syndrome whose symptoms partially overlap with that of BRWS. However, several patients with Fryns-Aftimos were considered not to fit into the ACTB and ACTG1 spectrum because of their severe impairment and additional malformations. We report on three patients who had been diagnosed with FAS. All three patients carry a mutation in the ACTB gene. On the basis of the ACTB mutations and analysis of the clinical findings, we reclassify the diagnosis of these patients as severe BRWS. We suggest that mutations in ACTB cause a distinctly more severe phenotype than ACTG1 mutations, despite the structural similarity of beta- and gamma-actins and their overlapping expression pattern. We expand the spectrum of BRWS and confirm that FAS is not a separate entity but an early and severe manifestation of BRWS.
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Di Donato
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Rump
authors.affiliation: Institute of Human Genetics, Johann Wolfgang Goethe University Hospital, Frankfurt/Main, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Koenig
authors.affiliation: Departments of Pediatrics and Human Genetics, McGill University, Montreal, PQ, Canada.
authors.forename: V M
authors.initials: VM
authors.lastname: Der Kaloustian
authors.affiliation: Department of Medical Genetics, Montreal Children's Hospital, McGill University Health Centre, Montreal, PQ, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Halal
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Sonntag
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Krause
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Hackmann
authors.affiliation: Institute of Diagnostic Radiology, Department of Pediatric Radiology, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Hahn
authors.affiliation: Institute for Clinical Genetics, Faculty of Medicine Carl Gustav Carus TU Dresden, Dresden, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Schrock
authors.affiliation: Department of Genetics, Robert-Debré Hospital, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Verloes
mesh_terms: D000015:Abnormalities, Multiple / Q000145:classification / Q000235:genetics* / Q000473:pathology; D000199:Actins / Q000235:genetics*; D000293:Adolescent; D002648:Child; D004252:DNA Mutational Analysis; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D020125:Mutation, Missense; D010641:Phenotype; D012720:Severity of Illness Index; D013577:Syndrome; D055815:Young Adult
chemical_list: C000594243:ACTG1 protein, human; D000199:Actins