scholarly journals Rett Syndrome in Males: The Different Clinical Course in Two Brothers with the Same Microduplication MECP2 Xq28

Author(s):  
Maria Bernarda Pitzianti ◽  
Angelo Santamaria Palombo ◽  
Susanna Esposito ◽  
Augusto Pasini

Rett syndrome (RTT) is a neurodevelopmental disorder with a genetic basis that is associated with the mutation of the X-linked methyl-CpG binding protein 2 (MECP2) gene in approximately 90% of patients. RTT is characterized by a brief period of normal development followed by loss of acquired skills and evolution towards impairment of brain and motor functions and multi-organ dysfunction. Originally, RTT was considered lethal in males as it has an X-linked dominant inheritance. However, although this syndrome has a higher incidence in females, rare cases are also documented in males. Here, we describe the case of an 11-year-old male patient with a microduplication MECP2 Xq28. Our patient is currently living, while his older brother with the same mutation died at the age of 9 years. We showed that the role of MECP2 as an epigenetic modulator and the X-chromosome inactivation pattern can explain the lethal clinical form of the older brother with the same microduplication MECP2 Xq28 presented by our patient who is still alive. Given the limited case history of RTT in males, further studies are needed to better characterize this syndrome in males and consequently improve the currently available therapeutic strategies.

1970 ◽  
Vol 28 (1) ◽  
pp. 20-22
Author(s):  
MR Pathak ◽  
A Neopane

Rett Syndrome (RS) is a neurodevelopmental disorder in which girls are predominantly affected, transmitted as an X linked dominant inheritance and caused by mutation in MECP2 gene. The basic presentation in RS is regression of previously acquired developmental milestones, lack of social interaction skills and acquired microcephaly after a certain age, which starts in early months of infancy. It is frequently misdiagnosed as autism, cerebral palsy or nonspecific developmental delay and is relatively frequent cause of delayed development in girls. Diagnosis is mainly clinical after excluding the neurodegenerative and other causes of delayed milestones. The chromosomal analysis, confirmatory tool for diagnosis is available in limited centers. The treatment is mainly speech therapy and counseling though few pharmacological agents have been tried with little response. A ten years age girl presented with the history of seizures, regression of speech and delayed motor milestones in our out patient clinic which was subsequently diagnosed as Rett Syndrome. Key Words: Rett syndrome, Developmental Regression, X Linked Dominant.    DOI = 10.3126/jnps.v28i1.1402   J. Nepal Paediatr. Soc. Vol.28(1) p.20-22


Science ◽  
2021 ◽  
Vol 373 (6551) ◽  
pp. 226-231 ◽  
Author(s):  
Yasuka Toda ◽  
Meng-Ching Ko ◽  
Qiaoyi Liang ◽  
Eliot T. Miller ◽  
Alejandro Rico-Guevara ◽  
...  

Early events in the evolutionary history of a clade can shape the sensory systems of descendant lineages. Although the avian ancestor may not have had a sweet receptor, the widespread incidence of nectar-feeding birds suggests multiple acquisitions of sugar detection. In this study, we identify a single early sensory shift of the umami receptor (the T1R1-T1R3 heterodimer) that conferred sweet-sensing abilities in songbirds, a large evolutionary radiation containing nearly half of all living birds. We demonstrate sugar responses across species with diverse diets, uncover critical sites underlying carbohydrate detection, and identify the molecular basis of sensory convergence between songbirds and nectar-specialist hummingbirds. This early shift shaped the sensory biology of an entire radiation, emphasizing the role of contingency and providing an example of the genetic basis of convergence in avian evolution.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Kerstin Ure ◽  
Hui Lu ◽  
Wei Wang ◽  
Aya Ito-Ishida ◽  
Zhenyu Wu ◽  
...  

The postnatal neurodevelopmental disorder Rett syndrome, caused by mutations in MECP2, produces a diverse array of symptoms, including loss of language, motor, and social skills and the development of hand stereotypies, anxiety, tremor, ataxia, respiratory dysrhythmias, and seizures. Surprisingly, despite the diversity of these features, we have found that deleting Mecp2 only from GABAergic inhibitory neurons in mice replicates most of this phenotype. Here we show that genetically restoring Mecp2 expression only in GABAergic neurons of male Mecp2 null mice enhanced inhibitory signaling, extended lifespan, and rescued ataxia, apraxia, and social abnormalities but did not rescue tremor or anxiety. Female Mecp2+/- mice showed a less dramatic but still substantial rescue. These findings highlight the critical regulatory role of GABAergic neurons in certain behaviors and suggest that modulating the excitatory/inhibitory balance through GABAergic neurons could prove a viable therapeutic option in Rett syndrome.


1996 ◽  
Vol 1 (6) ◽  
pp. 343-347 ◽  
Author(s):  
JC Sipe ◽  
JS Romine ◽  
JA Koziol ◽  
R McMillan ◽  
J Zyroff ◽  
...  

Cladribine is a new type of drug with properties of selective lymphocyte suppression that appear to favorably alter the clinical course of progressive multiple sclerosis (MS). The history of the development of cladribine treatment in chronic progressive MS is discussed, and the application of cladribine treatment to progressive multiple sclerosis in a double-blind, placebo crossover study is reviewed. Cladribine selectively targets both resting and dividing lymphocytes and may be able to destroy the activated lymphocytes that induce CNS demyelination, thus producing stabilization or improvement in chronic MS. Although the role of cladribine has not yet been fully defined, additional studies are underway to evaluate the efficacy and safety of cladribine in both progressive MS and relapsing-remitting MS.


2011 ◽  
Vol 26 (11) ◽  
pp. 1429-1433 ◽  
Author(s):  
Natalija Krajnc ◽  
Neža Župančič ◽  
Jasna Oražem

Rett syndrome is a neurodevelopmental disorder predominately affecting females. The majority of patients have epilepsy in the early stages of the disease. This study evaluates the clinical course of epilepsy and the effect of antiepileptic drug treatment in Rett syndrome using retrospective data analysis. Epilepsy was present in 16 of 19 (84%) patients with Rett syndrome in this series. The mean age of seizure onset was 4 years. Remission of seizures was achieved after the first monotherapy in 56% and after the second monotherapy in 18.5% of patients. Valproate, lamotrigine, and carbamazepine were the drugs used most frequently as monotherapy. Valproate monotherapy was highly effective as 75% of treated patients achieved seizure remission. Monotherapy with lamotrigine or carbamazepine was effective in half of the treated patients. There was a clear tendency toward seizure remission after the age of 15 years.


2021 ◽  
Vol 12 ◽  
Author(s):  
Katrina V. Good ◽  
John B. Vincent ◽  
Juan Ausió

Mutations in methyl CpG binding protein 2 (MeCP2) are the major cause of Rett syndrome (RTT), a rare neurodevelopmental disorder with a notable period of developmental regression following apparently normal initial development. Such MeCP2 alterations often result in changes to DNA binding and chromatin clustering ability, and in the stability of this protein. Among other functions, MeCP2 binds to methylated genomic DNA, which represents an important epigenetic mark with broad physiological implications, including neuronal development. In this review, we will summarize the genetic foundations behind RTT, and the variable degrees of protein stability exhibited by MeCP2 and its mutated versions. Also, past and emerging relationships that MeCP2 has with mRNA splicing, miRNA processing, and other non-coding RNAs (ncRNA) will be explored, and we suggest that these molecules could be missing links in understanding the epigenetic consequences incurred from genetic ablation of this important chromatin modifier. Importantly, although MeCP2 is highly expressed in the brain, where it has been most extensively studied, the role of this protein and its alterations in other tissues cannot be ignored and will also be discussed. Finally, the additional complexity to RTT pathology introduced by structural and functional implications of the two MeCP2 isoforms (MeCP2-E1 and MeCP2-E2) will be described. Epigenetic therapeutics are gaining clinical popularity, yet treatment for Rett syndrome is more complicated than would be anticipated for a purely epigenetic disorder, which should be taken into account in future clinical contexts.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Clara Alice Musi ◽  
Anna Maria Castaldo ◽  
Anna Elisa Valsecchi ◽  
Sara Cimini ◽  
Noemi Morello ◽  
...  

Abstract Background Rett syndrome (RTT) is a monogenic X-linked neurodevelopmental disorder characterized by loss-of-function mutations in the MECP2 gene, which lead to structural and functional changes in synapse communication, and impairments of neural activity at the basis of cognitive deficits that progress from an early age. While the restoration of MECP2 in animal models has been shown to rescue some RTT symptoms, gene therapy intervention presents potential side effects, and with gene- and RNA-editing approaches still far from clinical application, strategies focusing on signaling pathways downstream of MeCP2 may provide alternatives for the development of more effective therapies in vivo. Here, we investigate the role of the c-Jun N-terminal kinase (JNK) stress pathway in the pathogenesis of RTT using different animal and cell models and evaluate JNK inhibition as a potential therapeutic approach. Results We discovered that the c-Jun N-terminal kinase (JNK) stress pathway is activated in Mecp2-knockout, Mecp2-heterozygous mice, and in human MECP2-mutated iPSC neurons. The specific JNK inhibitor, D-JNKI1, promotes recovery of body weight and locomotor impairments in two mouse models of RTT and rescues their dendritic spine alterations. Mecp2-knockout presents intermittent crises of apnea/hypopnea, one of the most invalidating RTT pathological symptoms, and D-JNKI1 powerfully reduces this breathing dysfunction. Importantly, we discovered that also neurons derived from hiPSC-MECP2 mut show JNK activation, high-phosphorylated c-Jun levels, and cell death, which is not observed in the isogenic control wt allele hiPSCs. Treatment with D-JNKI1 inhibits neuronal death induced by MECP2 mutation in hiPSCs mut neurons. Conclusions As a summary, we found altered JNK signaling in models of RTT and suggest that D-JNKI1 treatment prevents clinical symptoms, with coherent results at the cellular, molecular, and functional levels. This is the first proof of concept that JNK plays a key role in RTT and its specific inhibition offers a new and potential therapeutic tool to tackle RTT.


2017 ◽  
Vol 126 (9) ◽  
pp. 640-645 ◽  
Author(s):  
Chiara Mezzedimi ◽  
Walter Livi ◽  
Claudio De Felice ◽  
Serena Cocca

Objectives: Rett syndrome (RS) is a neurodevelopmental disorder and the second major cause of mental retardation in females. The aim of this study was to evaluate swallowing problems of RS patients by endoscopic assessment and compile a list of suggestions for managing feeding and preventing complications. Methods: The sample consisted of 61 female patients (mean age = 13.6 years, range, 2-33 years) admitted to the Department of Neuropsychiatry, where they had previously been diagnosed with RS. Speech evaluation associated with observation during mealtimes was useful to formulate suggestions for caregivers. Results: Progressive deterioration of feeding was commonly noted by caregivers. Fifty-four patients had a history of recurrent episodes of bronchitis. Oral apraxia, dyskinetic tongue movements, prolonged oral stage, and poor bolus formation were the most common findings in all patients. Conclusions: Dysphagia was primarily limited to oral preparatory phases, while the pharyngeal phase was normal in most patients. The high percentage of dysphagia suggests the need to accurately monitor the feeding capability of RS children. It is critical to correctly inform caregivers about safe swallowing procedures to reduce the incidence of fatal complications.


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