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Copenhagen, Denmark

Ravn K.,Center for Rett Syndrome | Ravn K.,Center for Applied Human Molecular Genetics | Roende G.,Center for Rett Syndrome | Duno M.,Copenhagen University | And 5 more authors.
Orphanet Journal of Rare Diseases | Year: 2011

Background: Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder, which is usually caused by de novo mutations in the MECP2 gene. More than 70% of the disease causing MECP2 mutations are eight recurrent C to T transitions, which almost exclusively arise on the paternally derived X chromosome. About 10% of the RTT cases have a C-terminal frameshift deletion in MECP2. Only few RTT families with a segregating MECP2 mutation, which affects female carriers with a phenotype of mental retardation or RTT, have been reported in the literature. In this study we describe two new RTT families with three and four individuals, respectively, and review the literature comparing the type of mutations and phenotypes observed in RTT families with those observed in sporadic cases. Based on these observations we also investigated origin of mutation segregation to further improve genetic counselling. Methods. MECP2 mutations were identified by direct sequencing. XCI studies were performed using the X-linked androgen receptor (AR) locus. The parental origin of de novo MECP2 frameshift mutations was investigated using intronic SNPs. Results: In both families a C-terminal frameshift mutation segregates. Clinical features of the mutation carriers vary from classical RTT to mild mental retardation. XCI profiles of the female carriers correlate to their respective geno-/phenotypes. The majority of the de novo frameshift mutations occur on the paternally derived X chromosome (7/9 cases), without a paternal age effect. Conclusions: The present study suggests a correlation between the intrafamilial phenotypic differences observed in RTT families and their respective XCI pattern in blood, in contrast to sporadic RTT cases where a similar correlation has not been demonstrated. Furthermore, we found de novo MECP2 frameshift mutations frequently to be of paternal origin, although not with the same high paternal occurrence as in sporadic cases with C to T transitions. This suggests further investigations of more families. This study emphasizes the need for thorough genetic counselling of families with a newly diagnosed RTT patient. © 2011 Ravn et al; licensee BioMed Central Ltd.

Downs J.,University of Western Australia | Downs J.,Curtin University Australia | Stahlhut M.,Center for Rett Syndrome | Wong K.,University of Western Australia | And 4 more authors.
PLoS ONE | Year: 2016

Rett syndrome is a pervasive neurodevelopmental disorder associated with a pathogenic mutation on the MECP2 gene. Impaired movement is a fundamental component and the Rett Syndrome Gross Motor Scale was developed to measure gross motor abilities in this population. The current study investigated the validity and reliability of the Rett Syndrome Gross Motor Scale. Video data showing gross motor abilities supplemented with parent report data was collected for 255 girls and women registered with the Australian Rett Syndrome Database, and the factor structure and relationships between motor scores, age and genotype were investigated. Clinical assessment scores for 38 girls and women with Rett syndrome who attended the Danish Center for Rett Syndrome were used to assess consistency of measurement. Principal components analysis enabled the calculation of three factor scores: Sitting, Standing and Walking, and Challenge. Motor scores were poorer with increasing age and those with the p.Arg133Cys, p.Arg294 or p.Arg306Cys mutation achieved higher scores than those with a large deletion. The repeatability of clinical assessment was excellent (intraclass correlation coefficient for total score 0.99, 95% CI 0.93 0.98). The standard error of measurement for the total score was 2 points and we would be 95% confident that a change 4 points in the 45-point scale would be greater than within-subject measurement error. The Rett Syndrome Gross Motor Scale could be an appropriate measure of gross motor skills in clinical practice and clinical trials. © 2016 Downs et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Roende G.,Center for Rett Syndrome | Ravn K.,Center for Rett Syndrome | Fuglsang K.,Center for Rett Syndrome | Andersen H.,Copenhagen University | And 4 more authors.
Pediatric Research | Year: 2011

We present the first case-control study addressing both fracture occurrence and fracture mechanisms in Rett syndrome (RTT). Two previous studies have shown increased fracture risk in RTT. This was also our hypothesis regarding the Danish RTT population. Therefore, we investigated risk factors associated with low-energy trauma and the association to methyl-CpG-binding protein 2 (MECP2) mutations. A total of 61 female patients with RTT and 122 healthy controls matched according to age and pubertal/menopause status were examined by questionnaires, bone biochemical markers in blood, and clinical and X-ray evaluations. National register search on fracture diagnoses was done to obtain complete fracture histories. Our results showed that patients with RTT sustained significantly more low-energy fractures from early age compared with controls, even though overall fracture occurrence apparently was not increased. Low-energy fractures were significantly associated with less mobility and lack of ambulation. Associations with MECP2 mutations or epilepsy were not demonstrated, contrary to previous findings. Blood biochemistry indicated a possible need for D vitamin supplementation in RTT. Our study casts light on fracture occurrence in RTT and points to a need for future research in bone development and fracture risk to establish directions for improved prevention and treatment of low-energy fractures in RTT. Copyright © 2011 International Pediatric Research Foundation, Inc.

Roende G.,Center for Rett Syndrome | Ravn K.,Center for Rett Syndrome | Fuglsang K.,Center for Rett Syndrome | Andersen H.,Copenhagen University | And 3 more authors.
Journal of Bone and Mineral Research | Year: 2011

Low bone mass is reported in growth-retarded patients harboring mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene causing Rett syndrome (RTT). We present the first study addressing both bone mineral density (BMD) and bone size in RTT. Our object was to determine whether patients with RTT do have low BMD when correcting for smaller bones by examination with dual-energy X-ray absorptiometry (DXA). We compared areal BMD (aBMD spine and aBMD total hip) and volumetric bone mineral apparent density (vBMAD spine and vBMAD neck) in 61 patients and 122 matched healthy controls. Further, spine and hip aBMD and vBMAD of patients were associated with clinical risk factors of low BMD, low-energy fractures, MECP2 mutation groups, and X chromosome inactivation (XCI). Patients with RTT had reduced bone size on the order of 10% and showed lower values of spine and hip aBMD and vBMAD (p<.001) adjusted for age, pubertal status, and body mass index (BMI). aBMD spine, vBMAD spine, and aBMD total hip were associated with low-energy fractures (p<.05). Walking was significantly associated to aBMD total hip and vBMAD neck adjusted for age and body mass index (BMI). Further, vBMAD neck was significantly associated to a diagnosis of epilepsy, antiepileptic treatment, and MECP2 mutation group, but none of the associations with vBMAD neck remained clinically significant in a multiple adjusted model including age and BMI. Neither aBMD spine, vBMAD spine, nor aBMD total hip were significantly associated with epilepsy, antiepileptic treatment, MECP2 mutation group, XCI, or vitamin D status. Low bone mass and small bones are evident in RTT, indicating an apparent low-bone-formation phenotype. © 2011 American Society for Bone and Mineral Research.

Grillo E.,University of Siena | Villard L.,French Institute of Health and Medical Research | Villard L.,Aix - Marseille University | Clarke A.,University of Cardiff | And 26 more authors.
Human Mutation | Year: 2012

Rett syndrome (RTT) is a neurodevelopmental disorder with one principal phenotype and several distinct, atypical variants (Zappella, early seizure onset and congenital variants). Mutations in MECP2 are found in most cases of classic RTT but at least two additional genes, CDKL5 and FOXG1, can underlie some (usually variant) cases. There is only limited correlation between genotype and phenotype. The Rett Networked Database () has been established to share clinical and genetic information. Through an "adaptor" process of data harmonization, a set of 293 clinical items and 16 genetic items was generated; 62 clinical and 7 genetic items constitute the core dataset; 23 clinical items contain longitudinal information. The database contains information on 1838 patients from 11 countries (December 2011), with or without mutations in known genes. These numbers can expand indefinitely. Data are entered by a clinician in each center who supervises accuracy. This network was constructed to make available pooled international data for the study of RTT natural history and genotype-phenotype correlation and to indicate the proportion of patients with specific clinical features and mutations. We expect that the network will serve for the recruitment of patients into clinical trials and for developing quality measures to drive up standards of medical management. © 2012 Wiley Periodicals, Inc.

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