In:
The Journal of Clinical Endocrinology & Metabolism, The Endocrine Society, Vol. 92, No. 11 ( 2007-11-01), p. 4467-4471
Abstract:
Context: Mandibuloacral dysplasia type A (MADA; OMIM 248370) is a rare progeroid syndrome characterized by dysmorphic craniofacial and skeletal features, lipodystrophy, and metabolic complications. Most Italian patients carry the same homozygous missense mutation (p.R527H) in the C-terminal tail domain of the LMNA gene, which encodes lamin A/C, an intermediate filament component of the nuclear envelope. Objective: The objective of the study was to identify novel LMNA mutations in individuals with clinical characteristics (bird-like facies, mandibular and clavicular hypoplasia, acroosteolysis, lipodystrophy, alopecia) observed in other well-known patients. Design: The LMNA gene was sequenced. Functional properties of the mutant alleles were investigated. Patient: We report a 27-yr-old Italian woman showing a MADA-like phenotype. Features include a hypoplastic mandible, acroosteolysis, pointed nose, partial loss of sc fat, and a progeric appearance. Due to the absence of clavicular dysplasia and normal metabolic profiles, generally associated with muscle hyposthenia and generalized hypotonia, this phenotype can be considered an atypical laminopathy. Results: We identified a patient compound heterozygote for the p.R527H and p.V440M alleles. The patient’s cells showed nuclear shape abnormalities, accumulation of pre-lamin A, and irregular lamina thickness. Lamins A and C showed normal expression and localization. The electron microscopy detected heterochromatin defects with a pattern similar to those observed in other laminopathies. However, chromatin analysis showed a normal distribution pattern of the major heterochromatin proteins: heterochromatin protein-1β and histone H3 methylated at lysine 9. Conclusions: The clinical and cellular features of this patient show overlapping laminopathy phenotypes that could be due to the combination of p.R527H and p.V440M alleles.
Type of Medium:
Online Resource
ISSN:
0021-972X
,
1945-7197
DOI:
10.1210/jc.2007-0116
Language:
English
Publisher:
The Endocrine Society
Publication Date:
2007
detail.hit.zdb_id:
2026217-6
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