A recurrent homozygous LMNA missense variant p.Thr528Met causes atypical progeroid syndrome characterized by mandibuloacral dysostosis, severe muscular dystrophy, and skeletal deformities.
Am J Med Genet A
; 191(9): 2274-2289, 2023 09.
Article
en En
| MEDLINE
| ID: mdl-37387251
ABSTRACT
Atypical progeroid syndromes (APS) are premature aging syndromes caused by pathogenic LMNA missense variants, associated with unaltered expression levels of lamins A and C, without accumulation of wild-type or deleted prelamin A isoforms, as observed in Hutchinson-Gilford progeria syndrome (HGPS) or HGPS-like syndromes. A specific LMNA missense variant, (p.Thr528Met), was previously identified in a compound heterozygous state in patients affected by APS and severe familial partial lipodystrophy, whereas heterozygosity was recently identified in patients affected by Type 2 familial partial lipodystrophy. Here, we report four unrelated boys harboring homozygosity for the p.Thr528Met, variant who presented with strikingly homogeneous APS clinical features, including osteolysis of mandibles, distal clavicles and phalanges, congenital muscular dystrophy with elevated creatine kinase levels, and major skeletal deformities. Immunofluorescence analyses of patient-derived primary fibroblasts showed a high percentage of dysmorphic nuclei with nuclear blebs and typical honeycomb patterns devoid of lamin B1. Interestingly, in some protrusions emerin or LAP2α formed aberrant aggregates, suggesting pathophysiology-associated clues. These four cases further confirm that a specific LMNA variant can lead to the development of strikingly homogeneous clinical phenotypes, in these particular cases a premature aging phenotype with major musculoskeletal involvement linked to the homozygous p.Thr528Met variant.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Progeria
/
Envejecimiento Prematuro
/
Disostosis
/
Lipodistrofia Parcial Familiar
/
Distrofias Musculares
Tipo de estudio:
Etiology_studies
Límite:
Humans
Idioma:
En
Revista:
Am J Med Genet A
Asunto de la revista:
GENETICA MEDICA
Año:
2023
Tipo del documento:
Article
País de afiliación:
Argelia