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1.
J Peripher Nerv Syst ; 20(2): 79-85, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26110377

RESUMO

There has been limited information from population studies regarding the overall frequency of the common 1.5-Mb 17p11.2 deletion and even scarcer data regarding the overall frequency of PMP22 micromutations in patients with a clinical suspicion of hereditary neuropathy with liability to pressure palsies (HNPP). We have analysed 100 consecutive Greek patients referred for HNPP genetic testing over a 15-year period to our Neurogenetics Unit in Athens, a reference centre for all regions of Greece. All patients were screened for the 1.5-Mb deletion and a selected subgroup of deletion-negative patients for PMP22 micromutations. Mutation-positive and mutation-negative patients were compared for various clinical parameters. In total, 54 mutation-positive patients were identified. In index cases, the deletion frequency was 47.8%, and the PMP22 micromutation frequency was 2.2%. Within mutation-positive patients, the common deletion represented 95.7% and PMP22 micromutations 4.3% of cases. Two previously reported PMP22 micromutations (c.364_365delCC and c.79-2A>G) were detected. HNPP index cases had a 2.8-1 male-to-female ratio, similar to mutation-negative patients. A typical phenotype (recurrent or isolated palsies) was present in 82.4% of symptomatic HNPP cases, significantly higher than mutation-negative patients. Sensitivity of proposed electrophysiological diagnostic criteria for HNPP was calculated at 95.7% and specificity at 80.5%. In conclusion, the common HNPP deletion accounts for ∼50% and PMP22 micromutations for ∼2% of cases in a large consecutive cohort of patients with suspected HNPP. The mutational and phenotypic spectrum of HNPP is similar in the Greek population compared with other populations. Proposed electrophysiological diagnostic criteria perform satisfactorily in everyday clinical practice.


Assuntos
Artrogripose/genética , Artrogripose/fisiopatologia , Neuropatia Hereditária Motora e Sensorial/genética , Neuropatia Hereditária Motora e Sensorial/fisiopatologia , Proteínas da Mielina/genética , Síndrome de Smith-Magenis/genética , Adolescente , Adulto , Idoso , Artrogripose/diagnóstico , Criança , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Análise Mutacional de DNA , Feminino , Grécia , Neuropatia Hereditária Motora e Sensorial/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Fenótipo , Adulto Jovem
2.
Phys Rev E ; 106(2-1): 024301, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36109952

RESUMO

In this paper, we focus on the link density in random geometric graphs (RGGs) with a distance-based connection function. After deriving the link density in D dimensions, we focus on the two-dimensional (2D) and three-dimensional (3D) space and show that the link density is accurately approximated by the Fréchet distribution, for any rectangular space. We derive expressions, in terms of the link density, for the minimum number of nodes needed in the 2D and 3D spaces to ensure network connectivity. These results provide first-order estimates for, e.g., a swarm of drones to provide coverage in a disaster or crowded area.

3.
Case Rep Neurol Med ; 2015: 841897, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25883816

RESUMO

We report a patient with relapsing remitting multiple sclerosis (MS) and X-linked Charcot-Marie-Tooth disease (CMTX), carrying a GJB1 mutation affecting connexin-32 (c.191G>A, p. Cys64Tyr) which was recently reported by our group. This is the third case report of a patient with CMTX developing MS, but it is unique in the fact that other family members carrying the same mutation were found to have asymptomatic central nervous system (CNS) involvement (diffuse white matter hyperintensity on brain MRI and extensor plantars). Although this may be a chance association, the increasing number of cases with CMTX and MS, especially with mutations involving the CNS, may imply some causative effect and provide insights into MS pathogenesis.

4.
J Neurol Sci ; 341(1-2): 158-61, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24768312

RESUMO

Charcot-Marie-Tooth (CMT) disease, the most common hereditary neuropathy, is clinically and genetically heterogeneous. X-linked CMT (CMTX) is usually caused by mutations in the gap junction protein b 1 gene (GJB1) coding for connexin 32 (Cx32). The clinical manifestations of CMTX are characterized by significant variability, with some patients exhibiting central nervous system (CNS) involvement. We report four novel mutations in GJB1, c.191G>A (p.Cys64Tyr), c.508G>T (p.Val170Phe), c.778A>G (p.Lys260Glu) and c.300C>G (p.His100Gln) identified in four unrelated Greek families. These mutations were characterized by variable phenotypic expression, including a family with the Roussy-Lévy syndrome, and three of them were associated with mild clinical CNS manifestations.


Assuntos
Sistema Nervoso Central/patologia , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/patologia , Conexinas/genética , Mutação/genética , Adolescente , Adulto , Saúde da Família , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Fenótipo , Proteína beta-1 de Junções Comunicantes
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