De Novo ACTG1 Variant Expands the Phenotype and Genotype of Partial Deafness and Baraitser-Winter Syndrome.
Int J Mol Sci
; 23(2)2022 Jan 08.
Article
en En
| MEDLINE
| ID: mdl-35054877
ABSTRACT
Actin molecules are fundamental for embryonic structural and functional differentiation; γ-actin is specifically required for the maintenance and function of cytoskeletal structures in the ear, resulting in hearing. Baraitser-Winter Syndrome (B-WS, OMIM #243310, #614583) is a rare, multiple-anomaly genetic disorder caused by mutations in either cytoplasmically expressed actin gene, ACTB (ß-actin) or ACTG1 (γ-actin). The resulting actinopathies cause characteristic cerebrofrontofacial and developmental traits, including progressive sensorineural deafness. Both ACTG1-related non-syndromic A20/A26 deafness and B-WS diagnoses are characterized by hypervariable penetrance in phenotype. Here, we identify a 28th patient worldwide carrying a mutated γ-actin ACTG1 allele, with mildly manifested cerebrofrontofacial B-WS traits, hypervariable penetrance of developmental traits and sensorineural hearing loss. This patient also displays brachycephaly and a complete absence of speech faculty, previously unreported for ACTG1-related B-WS or DFNA20/26 deafness, representing phenotypic expansion. The patient's exome sequence analyses (ES) confirms a de novo ACTG1 variant previously unlinked to the pathology. Additional microarray analysis uncover no further mutational basis for dual molecular diagnosis in our patient. We conclude that γ-actin c.542C > T, p.Ala181Val is a dominant pathogenic variant, associated with mildly manifested facial and cerebral traits typical of B-WS, hypervariable penetrance of developmental traits and sensorineural deafness. We further posit and present argument and evidence suggesting ACTG1-related non-syndromic DFNA20/A26 deafness is a manifestation of undiagnosed ACTG1-related B-WS.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Actinas
/
Sordera
/
Discapacidad Intelectual Ligada al Cromosoma X
/
Trastornos del Crecimiento
/
Hidrocefalia
/
Mutación
/
Obesidad
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2022
Tipo del documento:
Article
País de afiliación:
Polonia