EDUARDO DE PAULA ESTEPHAN
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- A common CHRNE mutation in Brazilian patients with congenital myasthenic syndrome(2018) ESTEPHAN, Eduardo de Paula; SOBREIRA, Claudia Ferreira da Rosa; SANTOS, Andre Cleriston Jose dos; TOMASELLI, Pedro Jose; MARQUES JR., Wilson; ORTEGA, Roberta Paiva Magalhes; COSTA, Marcela Camara Machado; SILVA, Andre Macedo Serafim da; MENDONCA, Rodrigo Holanda; CALDAS, Vitor Marques; ZAMBON, Antonio Alberto; ABATH NETO, Osorio; MARCHIORI, Paulo Euripedes; HEISE, Carlos Otto; REED, Umbertina Conti; AZUMA, Yoshiteru; TOPF, Ana; LOCHMULLER, Hanns; ZANOTELI, EdmarThe most common causes of congenital myasthenic syndromes (CMS) are CHRNE mutations, and some pathogenic allelic variants in this gene are especially frequent in certain ethnic groups. In the southern region of Brazil, a study found the c.130dupG CHRNE mutation in up to 33% of families with CMS. Here, we aimed to verify the frequency of this mutation among individuals with CMS in a larger cohort of CMS patients from different areas of Brazil and to characterize clinical features of these patients. Eighty-four patients with CMS, from 72 families, were clinically evaluated and submitted to direct sequencing of the exon 2 of CHRNE. The c.130dupG mutation was found in 32 patients (23 families), with 26 patients (19 families, 26.3%) in homozygosis, confirming its high prevalence in different regions of Brazil. Among the homozygous patients, the following characteristics were frequent: onset of symptoms before 2 years of age (92.3%), little functional restriction (92.3%), fluctuating symptoms (100%), ocular muscle impairment (96.1%), ptosis (100%), limb weakness (88.4%), response to pyridostigmine (100%), facial involvement (77%), and bulbar symptoms (70.8%). The pretest probability of finding at least one allele harbouring the c.130dupG mutation was 38.1%. Selecting only patients with impaired eye movement together with limb weakness and improvement with pyridostigmine, the probability increases to 72.2%. This clinical pre-selection of patients is likely a useful tool for regions where CHRNE mutations have a founder effect. In conclusion, the CHRNE mutation c.130dupG leads to fairly benign natural course of the disease with relative homogeneity.
- Mutations in PTPN11 could lead to a congenital myasthenic syndrome phenotype: a Noonan syndrome case series(2024) PUGLIESE, Alessia; MARINA, Adela Della; ESTEPHAN, Eduardo de Paula; ZANOTELI, Edmar; ROOS, Andreas; SCHARA-SCHMIDT, Ulrike; HENTSCHEL, Andreas; AZUMA, Yoshiteru; TOPF, Ana; THOMPSON, Rachel; POLAVARAPU, Kiran; LOCHMUELLER, HannsThe RASopathies are a group of genetic rare diseases caused by mutations affecting genes involved in the RAS/MAPK (RAS-mitogen activated protein kinase) pathway. Among them, PTPN11 pathogenic variants are responsible for approximately 50% of Noonan syndrome (NS) cases and, albeit to a lesser extent, of Leopard syndrome (LPRD1), which present a few overlapping clinical features, such as facial dysmorphism, developmental delay, cardiac defects, and skeletal deformities. Motor impairment and decreased muscle strength have been recently reported. The etiology of the muscle involvement in these disorders is still not clear but probably multifactorial, considering the role of the RAS/MAPK pathway in skeletal muscle development and Acetylcholine Receptors (AChR) clustering at the neuromuscular junction (NMJ). We report, herein, four unrelated children carrying three different heterozygous mutations in the PTPN11 gene. Intriguingly, their phenotypic features first led to a clinical suspicion of congenital myasthenic syndrome (CMS), due to exercise-induced fatigability with a variable degree of muscle weakness, and serum proteomic profiling compatible with a NMJ defect. Moreover, muscle fatigue improved after treatment with CMS-specific medication. Although the link between PTPN11 gene and neuromuscular transmission is unconfirmed, an increasing number of patients with RASopathies are affected by muscle weakness and fatigability. Hence, NS or LPDR1 should be considered in children with suspected CMS but negative genetic workup for known CMS genes or additional symptoms indicative of NS, such as facial dysmorphism or intellectual disability.