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Data were collected parenting stress, adaptive behavior, pain, and health issues from the caregivers of 35 girls and women with Rett syndrome (mean age = 20.3). A majority (60%) of parents reported stress in the clinical range on at least 1 subscale of the Parenting Stress Index–Short Form. Seizures and uncertainty about their daughter’s gastrointestinal pain experience were significantly associated with higher levels of parenting stress. No other child factors (adaptive behavior, age, residential status) were significantly related to parenting stress. Factors related to chronic health concerns (seizures, ambiguous pain presentation) may be important when considering family stress issues in relation to general outcomes for girls with Rett syndrome and related developmental disorders. [ABSTRACT FROM PUBLISHER]

The authors report a case of a 7-year-old girl with a progressive sensorimotor peripheral neuropathy with acute relapses associated with a desquamating purpuric rash, alopecia, and spinal cord atrophy. Distinctive features include systemic involvement with alopecia and rash, peripheral nervous system involvement with relapsing and remitting sensorimotor neuropathy, and central nervous system involvement with episodes of dystonic posturing and spinal cord atrophy. Extensive diagnostic evaluation for known causes of skin manifestations associated with peripheral neuropathy has failed to identify a cause for this patient’s condition. The authors discuss the case as an approach to the differential diagnosis and to highlight unusual features of this yet to be identified clinical entity. [ABSTRACT FROM AUTHOR]

Mutations in the X-linked cyclin dependent kinase like 5 (CDKL5) gene have been reported in approximately 80 patients since the first description in 2003. The clinical presentation partly corresponds with Rett syndrome, considering clinical features as intellectual disability, hypotonia, and poor visual, language, and motor development. However, these patients do not meet the consensus criteria for Rett syndrome since they lack the clear period of regression. Furthermore, in contrast to Rett syndrome, patients with CDKL5 mutations, have seizures or infantile spasms starting in the first weeks of life. We present clinical phenotype of 5 girls having a mutation in the CDKL5 gene. All mutations are novel and are pathogenic since they either lead to a frameshift in the reading frame or affect a consensus splice site. Four of the mutations are detected de novo in the affected girl. [ABSTRACT FROM PUBLISHER]

The early developmental history prior to the manifestation of Rett syndrome features is of clinical interest. This study describes the attainment of gross developmental milestones and regression, and assesses the relationships between genotype and age at diagnosis. The Australian Rett Syndrome Database and International Rett Syndrome Phenotype Database were used to source a total of 293 confirmed female subjects. Most girls learned to sit, were able to babble or use words, and approximately half learned to walk. Altered milestone attainment was associated with earlier diagnosis. There was variation in the acquisition of milestones, the age of regression, and the age of diagnosis by genotype. Most parents expressed concerns about unusual behaviors or development during infancy, and a more subtle atypical development during infancy was reported for most girls. It is important for clinicians to be aware of variable early development in Rett syndrome and that timely genetic testing is not precluded on this account. [ABSTRACT FROM PUBLISHER]

Loss of hand function is a core feature of Rett syndrome. This article describes longitudinal hand function at 3 time points for 72 subjects participating in the Australian Rett Syndrome Database. Approximately 40% of subjects with some grasping abilities lost skill over the 3- to 4-year period between video assessments. In these subjects, a decrease in hand function was seen less frequently in girls 13 to 19 years old than in those younger than 8 years, in subjects with some mobility compared with those who were wheelchair bound, and in those who had previously been able to finger feed. Relationships with the magnitude of change reflected these findings. Change in hand function did not vary with clinical severity. The results for all subjects were similar to results obtained when analysis was restricted to those with a pathogenic mutation. Variability in the longitudinal course of hand function in Rett syndrome was observed. [ABSTRACT FROM AUTHOR]

Rett syndrome is a genetic neurodevelopmental disorder that affects mainly girls, but mutations in the causative MECP2 gene have also been identified in boys with classic Rett syndrome and Rett syndrome-like phenotypes. We have studied a group of 28 boys with a neurodevelopmental disorder, 13 of which with a Rett syndrome-like phenotype; the patients had diverse clinical presentations that included perturbations of the autistic spectrum, microcephaly, mental retardation, manual stereotypies, and epilepsy. We analyzed the complete coding region of the MECP2 gene, including the detection of large rearrangements, and we did not detect any pathogenic mutations in the MECP2 gene in these patients, in whom the genetic basis of disease remained unidentified. Thus, additional genes should be screened in this group of patients. [ABSTRACT FROM AUTHOR]

Recent progress in our understanding of Rett syndrome has been dramatic. Against the background that the clinical features of Rett syndrome may be reversible, in part or in whole, substantial optimism has emerged regarding possible therapies. As such, it is timely to update recent research progress. This update summarizes research advances during the past 18 to 24 months in terms of clinical and translational research, as well as basic research. [ABSTRACT FROM AUTHOR]

Rett syndrome (RU) is an X-linked dominant neurodevelopment disorder, which is mainly caused by gene mutation of methyl-CpG-binding protein 2 (MECP2). The correlations between genotype, X chromosome inactivation (XCI), and phenotype have been studied, but the results are conflicting. In the present study, XCI patterns in patients and their mothers, parental origin of skewed X chromosome in patients, and the correlations between XCI, genotype, and phenotype were analyzed in 52 cases of RU with MECP2 mutations, 50 RU mothers, and 48 normal female controls. The results showed XCI and genotype had limitations in explaining all the phenotypic manifestations of RU. Other genomic factors have to be considered to explain the phenotypic differences. [ABSTRACT FROM AUTHOR]

The International Rett Syndrome Association (IRSA) North American database is the first comprehensive compilation of information in the United States and Canada on individuals with Rett syndrome or with another diagnosis in association with MECP2 mutations. The database contains specific information by diagnosis, mutation status, and mutation type and frequency on 1928 participants. Among the 1928 participants, 85.5% were typical, 13.4% were atypical, and 1.1% had MECP2 mutations but did not have Rett syndrome. MECP2 mutations were identified in 914 of 1059 participants (86%): 799 of 870 (92%) participants with typical Rett syndrome had an MECP2 mutation, 94 of 162 (58%) with atypical Rett syndrome had a mutation, and all 21 individuals diagnosed as Not Rett syndrome had a mutation. Missense-type mutations (39.0%) were slightly more common than nonsense type (35.1%). Individual mutation frequency for the 8 common mutations varied from 11.9% for Ti 58M to 4.4% for R106W; large deletions accounted for 6.4% and C-terminal truncations occurred in 8.8%. The remaining mutations (14.3%) occurred singly or in small numbers. This database provides a unique resource for expanding our understanding of Rett syndrome, for comparison with other national databases, and for future study including organization of clinical trials based on the expected emergence of fundamental therapies. [ABSTRACT FROM AUTHOR]

Rett syndrome is an X-linked dominant neurodevelopmental disorder. Mutation of the methyl-CpG-binding protein 2 gene (MECP2) is present in up to 96% of patients with Rett syndrome. Eight mutations represent the hotspot of MECP2 mutations (R106W, R133C, T158M, R168X, R255X, R270X, R294X, and R306C) in patients with classic Rett syndrome. The prevalence and survival rate of Rett syndrome among Chinese women was investigated. The 8 hotspot mutations and the A140V mutation were also studied in 4 cohorts of Chinese children (n = 144) actively followed up in our university neurodevelopmental center with classic Rett syndrome (n = 5), autism spectrum disorder (n = 94), epileptic encephalopathy of unknown cause (n = 22), and nonsyndromal mental retardation (n = 23). The prevalence of Rett syndrome among female Chinese younger than 35 years in Hong Kong West is 0.57 (95% confidence interval, 0.15-0.98) per 10 000, Survival is 100.0% at 10 years and 87.5% at 25 years. Three hotspot mutations (R106W, R255X, and R306C) were found in 3 girls with classic Rett syndrome. No hotspot MECP2 mutations were found in the other 3 cohorts. Screening of MECP2 mutations is not worthwhile in Chinese children with pure cognitive, autistic, or unexplained epileptic disorders without other signs of Rett syndrome. In the early stage of developmental arrest before developmental regression, MECP2 screening might be useful for girls with unexplained epileptic encephalopathy before full-blown classic Rett syndrome is evident. [ABSTRACT FROM AUTHOR]

Severe scoliosis in Rett syndrome is an important orthopedic, neurologic, and pediatric problem. The curve in Rett syndrome is of a neurologic type, has its highest incidence during early childhood, and shows rapid progression. In this study, the authors report the results of a 4-year follow-up of a 10-year-old Rett syndrome female patient with early onset and severe rapid progressive thoracolumbar scoliosis, The first signs of spinal deformity were documented at age 3 years. During adolescence, the patient developed a 115-degree thoracolumbal scoliosis with reduced respiratory volume due to a collapsing spine syndrome. To stop this life-threatening progression of the curve, the patient was treated by a 2-stage surgical procedure. The combination of an anterior release, halo traction, and posterior instrumented fusion f rom Th3 to L5 using a computer-assisted technique was performed. An excellent reduction of the deformity was achieved (postoperative 24-degree Cobb angle). After 4 years, the authors found a radiologically solid spinal fusion and no progression of the deformity. Operative treatment regimes and etiology of severe spinal deformities in Rett syndrome were discussed. The high perioperative risks in Rett syndrome patients who underwent spinal surgery may be reduced by an early cooperation between orthopedic and pediatric specialists. When considering recent data from literature, it can be concluded that an early correction of spine deformities in Rett syndrome patients may prevent a life-threatening collapsing spine syndrome. [ABSTRACT FROM AUTHOR]

Herein we present the largest retrospective case-control series of deep sedation in patients with Rett syndrome, including discussion of the unique aspects of Rett syndrome that make these patients at high risk for sedation. Twenty-one patients with Rett syndrome and 21 control patients who received propofol for deep sedation to facilitate lumbar puncture were compared. Patients with Rett syndrome required significantly less propofol than control patients when standardized for weight and the duration of the procedure (P = .004). Seven of the 21 patients with Rett syndrome compared with none of the control patients experienced a serious adverse event, most of which were due to prolonged apnea (P = .004). All adverse events were transient, and all patients returned to their baseline after the procedure was completed. Sedation of patients with Rett syndrome is associated with a relatively high rate of complications and should not be done without appropriate personnel available who recognize the risks of sedating this unique population. [ABSTRACT FROM AUTHOR]

Scoliosis is a common clinical manifestation of Rett syndrome, a neurodevelopmental disorder that almost exclusively affects girls. Following apparently normal development, these girls typically regress and lose previously attained cognitive, social, and motor skills. Severe intellectual and physical disabilities remain throughout life. Mutations in the methyl-CpG-binding protein 2 gene, MECP2, are detected in approximately 80% of cases and are associated with phenotypic variability. Population-based data on Australian cases were used to study the association between early developmental and genetic factors and the onset of scoliosis. The median age at scoliosis onset was 9.80 years, and three quarters of subjects had developed scoliosis by 13 years of age. Children with compromised early development before 6 months, those who were less mobile at 10 months, and those who never walked were more likely to have an earlier onset of scoliosis. When seven common point mutations and large genomic and C-terminal deletions were compared, the R294X mutation appeared to provide some protective effect against the development of scoliosis. [ABSTRACT FROM AUTHOR]

Most girls with Rett syndrome develop normally prior to the appearance of the typical symptoms. A presymptomatic phase is also observed in many inborn errors of metabolism that are included in newborn screening programs. Diagnostic testing for mutations or large genomic rearrangements involving methyl-CpG binding protein 2 gene (MECP2) is highly sensitive and identifies mutations in up to 95% of female individuals with classic Rett syndrome. This has prompted some to ask whether MECP2 testing should be included in newborn and prenatal screening programs. We review current and evolving practices in these programs, emphasizing their relevance to Rett syndrome. The availability of a reliable test and the characteristic early latent phase, which creates a window of opportunity for early treatment, favor universal newborn screening for Rett syndrome. However, the high cost and the lack of an effective presymptomatic treatment make universal newborn screening for Rett syndrome impractical at present. In contrast, prenatal diagnosis should be offered to the parents of an affected child if the responsible mutation has been identified in the index case. [ABSTRACT FROM AUTHOR]

Mutations in the X-linked gene encoding the methyl-CpG binding protein MeCP2 are the primary cause of classic and atypical Rett syndrome and have recently been shown to contribute to other neurodevelopmental disorders of varying severity. To determine whether there are molecular correlates to the phenotypic heterogeneity, numerous groups have performed genotype-phenotype correlation studies. These studies have yielded conflicting results, in part because they used different criteria for determining severity and classifying mutations. Evolution of the phenotype with age and variable expressivity arising from individual variability in X-chromosome inactivation patterns are among other reasons the findings varied. Nonetheless, evidence of differences in the phenotypic consequences of specific types of mutations is emerging. This review analyzes the available literature and makes recommendations for future studies. [ABSTRACT FROM AUTHOR]

The clinical signs of Rett syndrome, as well as neuropathology and brain imaging, suggest that the disorder disrupts neuronal circuits. Studies using receptor autoradiography demonstrate abnormalities in the density of excitatory glutamate and inhibitory-γaminobutyric acid (GABA) synaptic receptors in postmortem brain from young female subjects with Rett syndrome. MeCP2, the protein that is abnormal in most female individuals with Rett syndrome, is expressed predominantly in neurons and appears during development at the time of synapse formation. Studies of nasal epithelium from patients with Rett syndrome show that the maturation of olfactory receptor neurons is impeded prior to the time of synapse formation. Recent reports indicate that MeCP2 controls the expression of brain-derived neurotrophic factor and the DNA-binding homeobox protein Dlx5. Brain-derived neurotrophic factor enhances glutamate neurotransmission at excitatory synapses, whereas Dlx5 is expressed in most GABAergic neurons and stimulates the synthesis of GABA. Taken together, this information supports the hypothesis that Rett syndrome is a genetic disorder of synapse development, especially synapses that use glutamate and GABA as neurotransmitters. [ABSTRACT FROM AUTHOR]

Rett syndrome is a unique neuro developmental disorder, with onset of hypotonia, autistic tendency, and abnormalities of fine finger movements and gross movements of the anus in early infancy. Clinical features include specific age-dependent symptoms. Studies of early and late signs correlated locomotive dysfunction to language disability and stereotypy to regression of higher cortical functions. Studies of sleep parameters revealed early hypofunction of brainstem aminergic neurons and late occurrence of hypofunction of dopaminergic neurons, followed by receptor supersensitivity. The syndrome's pathophysiology suggests that early hypofunction of aminergic neurons interferes with the development of higher neuronal systems. Particular symptoms surface at different ages throughout the natural course of Rett syndrome, with regressional and static periods. [ABSTRACT FROM AUTHOR]

Rett syndrome is a leading cause of postnatal neuro developmental regression. Rett syndrome is caused by mutations in MECP2, the gene encoding methyl-CpG binding protein 2. In up to 96% of all classic cases, Rett syndrome cases are caused by mutations or deletions in MECP2. The phenotypic spectrum of MECP2 mutations is broad and includes mental retardation with or without seizures, Angelman syndrome–like phenotype, and autism. Mecp308/Y mice carry a truncating mutation and display many of the features seen in Rett syndrome. Social behavior abnormalities and impaired social interactions in Mecp308/Y mice suggest that MeCP2 plays a role in modulating the activity of genes and neurons important for social interactions. Mice that overexpress MeCP2 at twice the endogenous levels develop a progressive neurologic disorder, demonstrating that MeCP2 levels are tightly regulated and raising the possibility that duplications or gain-of-function mutations of MECP2 might underlie some cases of neurodevelopmental X-linked disorders. [ABSTRACT FROM AUTHOR]

Rett syndrome is a neuro developmental disorder and an important cause of mental retardation and autistic behavior in girls and in a small group of boys. In 1999, mutation of the methyl-CpG binding protein 2 (MEGP2) gene encoding a transcriptional repressor on the X chromosome was found to cause Rett syndrome. Since this discovery, significant research has focused on the elucidation of its specific role in the central nervous system. Recent studies revealed that MECP2 is expressed in more differentiated neurons rather than in less differentiated neuroblasts and that MECP2 is involved in the maturation and maintenance of neurons, including dendritic arborization and axonal projections, rather than in early cell fate decisions in the mammalian brain. In this review, we summarize recent findings regarding regional, temporal, and cell type-specific MECP2 expression in the central nervous system; neurobiologic abnormalities in MECP2-mutant mice; and MECP2 target genes in the central nervous system. [ABSTRACT FROM AUTHOR]

Rett syndrome is a sporadic disorder (except for a few familial cases) occurring in 1 in 10,000 to 1 in 23,000 girls world- wide. It is associated with profound mental and motor handicap. About 90% of cases involve a mutation in the methyl-CpG binding protein 2 gene (MECP2). The role of this gene in the pathogenesis of this enigmatic disorder is being extensively investigated in animal models. Rett syndrome is associated with a complex phenotype that is unique in every aspect of its presentation, clinical physiology, chemistry, and pathology. Years of concentrated observations have defined the clinical presentation of classic Rett syndrome and its variants and related features (eg, neurophysiologic, radiologic, chemical, metabolic, and anatomic). This article reviews the neuropathology of Rett syndrome, which involves individual neurons, perhaps selected neurons, of decreased size, dendritic branching, and numbers of spines. This article also summarizes the studies in the human and mouse brain with Rett syndrome that are beginning to reveal the disorder's pathoetiology. [ABSTRACT FROM AUTHOR]

Rett syndrome is a neuro developmental disorder that in most cases is consequent to a mutation in the MECP2 gene. The central nervous system is the primary organ system involved in Rett syndrome. Neurophysiologic evaluations provide information concerning the developmental aspects of Rett syndrome and the character and extent of involvement of the central, peripheral, and autonomic nervous system pathways. Evoked potentials typically demonstrate intactness of peripheral auditory and visual pathways and suggest dysfunction of central or “higher” cortical pathways. Somatosensory evoked potentials can be characterized by “giant” responses, suggesting cortical hyperexcitability. Cortical hyperexcitability is further suggested by the findings of the electroencephalogram (EEG), which are primarily characterized by a loss of expected developmental features; the appearance of focal, multifocal, and generalized epileptiform abnormalities; and the occurrence of rhythmic slow (theta) activity, primarily in the frontal-central regions. Epileptic seizures are reported to occur frequently in Rett syndrome. However, many events presumed to be seizures have no EEG correlate during video-EEG monitoring. Impairment of the autonomic nervous system in Rett syndrome is suggested by an increased incidence of long Q-T intervals during electrocardiographic recordings and diminished heart rate variability. Autonomic nervous system dysfunction can contribute to the increased incidence of sudden unexpected death in Rett syndrome. [ABSTRACT FROM AUTHOR]

In 1999, mutations in the MEGP2 gene were identified as the primary cause of Rett syndrome. MEGP2 mutations can be found in 70% to 80% of all clinically defined Rett syndrome cases; in classic Rett syndrome, this frequency is even higher. In most cases, missense and nonsense mutations affecting functionally important domains can be found. Additionally, a hot spot for small deletions has been defined, and several gross rearrangements have also been described. Among female individuals with Rett syndrome, the spectrum of clinical phenotypes is broad, but most fulfill the diagnostic criteria. In contrast, male individuals with mutations in the MEGP2 gene are rare, and only a minority have clinical symptoms resembling Rett syndrome. [ABSTRACT FROM AUTHOR]

Rett syndrome is a neurodevelopmental disorder that occurs worldwide and predominantly affects girls. The MEGP2 gene has been put forward as the underlying gene. Interestingly, other clinical presentations in addition to Rett syndrome have been reported to be the results of deviations in MEGP2. This prompted us to outline a working hypothesis of how these diverse phenotypes are connected. Our aim was to summarize the clinical picture of deviations in MEGP2 at this moment to obtain a comprehensive overview. Thus, we have attempted to create a gradient, starting at the left with the most severely affected MEGP2-deviant subgroups, represented by boys who are diseased in the intrauterine phase or as neonates, and at the right, the most mildly affected subgroup, female asymptomatic carriers. In the center, with dominant numbers, we have placed classic Rett syndrome presentations, together with the late-onset Rett syndrome variant and preserved speech variant. In conclusion, we feel that it is important to emphasize that Rett syndrome is a strictly clinical diagnosis that is not identical to the far broader concept of MECP2 deviations. [ABSTRACT FROM AUTHOR]

Long-term clinical profiles of female patients with classic Rett syndrome are presented and exemplified by three cases, as experienced over four decades. Emphasized is the frequently surprisingly well-preserved eye contact and primitive memory, in contrast to a premature neuromuscular aging and often advanced peripheral atrophy, usually combined with dystonic-rigid signs that are predominantly right sided. [ABSTRACT FROM AUTHOR]

Rett syndrome is a neuro developmental disorder that primarily affects girls, most of whom have mutations in the transcription regulatory gene MEGP2. However, mutations in MEGP2 also have been identified in normal carrier female individuals, female individuals with mild learning disabilities and features of Angelman syndrome, and male individuals with Klinefelter syndrome or Rett syndrome–like features, fatal neonatal encephalopathy, and familial X-linked mental retardation with or without motor abnormalities. Therefore, molecular testing should be considered for a wide spectrum of individuals. As such, Rett syndrome remains a clinical diagnosis. In this article, we also discuss three recent developments: (1) the recognition of significant gallbladder dysfunction, especially in those 20 years of age or younger; (2) a clinical trial of folate and betaine, which produced no objective improvement but did yield a subjective increase in attention and interaction; and (3) measurement of cerebrospinal fluid folate levels in a large cohort, which yielded normal values, indicating no need for supplementation. [ABSTRACT FROM AUTHOR]

This article reports that on October 13, 2004, a symposium was held to determine how research findings enhance clinical practice for practitioners working with persons who have Rett syndrome and to identify the research needed to improve diagnostic accuracy and develop safe, effective therapies. Participants described diagnostic strategies, pathogenesis, therapies, and clinical trials and defined future research directions. Rett syndrome is a progressive neuro developmental disorder characterized by cognitive impairment, deficits in communication, stereotypic movements, and growth failure.

Rett syndrome is a severe neurodevelopmental disorder affecting girls, caused by mutations in the MECP2 gene. There are no population-based data on the extent and determinants of health service use in this disorder. The population-based registry, the Australian Rett Syndrome database, was the source of phenotype data. This also contains data from mutation screening and X-inactivation studies. Data on retrospective (n = 152) and prospective (n = 162) health service use were collected in 2000 from a questionnaire and a calendar study, respectively. Health service use was highest in younger cases (P = .001) and lowest in cases with milder phenotypes (P < .001). Random X-inactivation was associated with .service use (P = .02). Maternal education, phenotype, and individual mutations were determinants of health service use. The use of a retrospective and prospective data set enabled accurate assessment of service use in Rett syndrome. Both genetic and sociodemographic determinants of health service use were identified, with important implications for the optimal and equitable management of children with Rett syndrome. (J Child Neurol 2004; 19:42-50). [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the value of an e-mail listserv for parents of children with Rett syndrome, a rare neurologic disorder. This Web-based survey was completed by parents and carers. The setting was an e-mail listserv established by the International Rett Syndrome Association for parents of children with Rett syndrome and other interested persons. The participants included members of the e-mail listserv Rettnet. The main outcome measures were the perceived advantages and disadvantages of the listserv, overall rating of usefulness, and reasons for satisfaction or dissatisfaction. Most (81.5%) of the participants felt that Rettnet provided helpful advice concerning their child's management. They also indicated that Rettnet was useful in dealing with their child's education and as a source of carer support. They rated it highly (mean 8.1 on a scale of 1 to 10), and the most common reason given for recommending the service to other parents was the emotional support provided. E-mail listservs can play an important role in disseminating information and providing networking and support to parents of children with rare disorders. Their impact and influence warrant attention from health professionals, including neurologists. (J Child Neurol 2004; 19:902-907). [ABSTRACT FROM AUTHOR]

The British Isles Survey for Rett Syndrome stores longitudinal health data from clinical examinations and postal questionnaires to monitor health and severity in Rett syndrome, including the presence and severity of scoliosis and the effects of corrective surgery. Scoliosis is rarely present at birth (3% before regression) but usually appears by 25 years (87%). The degree tends to increase with growth and by 16 to 20 years, 43% (75 of 173) of cases with classic Rett syndrome reported severe or operated scoliosis. Surgical correction was reported in 91 classic cases. Following initial postoperative recovery, families considered that the operation had improved general well-being for 84% of individuals (42 of 50 classic cases with postoperative health reports). Thirteen of 50 patients walked independently before surgery, and 12 patients did so following surgery; 2 stopped walking, and 1 who had not walked began to do so. Scoliosis surgery usually benefited sitting posture (82% better, 10% worse), chest episodes (52% better, 6% worse), and digestion of food (42% better, 6% worse). However, toilet function was improved in only 10% and deteriorated in 20%. Families reported short-term problems at operation in 48% (24 of 50) and minor recurrence of scoliosis in 22% (11 of 50). Surgery in a specialized unit is satisfactory management for severe scoliosis in Rett syndrome. Recommendations include planning for surgery when the curve passes 40°, ensuring optimal nutrition before and after surgery, robust fixture of the whole spine in two stages, familiarization of the surgical team with the individual and the disorder before the operation, and inclusion of the main carer in the hospital care team. Parents form an important part of the management team. Families also require support during and after this stressful major procedure. (J Child Neurol 2003;18:703-708). [ABSTRACT FROM AUTHOR]

In 2001, the International Rett Syndrome Association funded the establishment of a World Wide Web-based database to collect and display the genetic data of children and adults with Rett syndrome from around the world. RettBASE () encompasses both published and unpublished data; includes pathogenic mutations, benign polymorphisms, and sequence variations of uncertain significance; and has a range of query capabilities, allowing for simple or complex interrogation of the database. To undertake genotype-phenotype correlations and to identify the likely subtle differences in phenotype, detailed phenotype data on large samples will be provided by the International Rett Syndrome Association International Phenotype database InterRett. InterRett is under development by the Australian Rett syndrome study group at the Telethon Institute for Child Health Research in Perth, Western Australia. It will collect data from clinicians and families and provide deidcntified, collated data on the Internet (). Data records will be linked with RettBASE through a common unique identifier. An international reference panel is advising on the development of the database. Data collection procedures from families and clinicians are currently being piloted. Full data collection from both groups began in the second half of 2003. Concurrently, the output database will be developed to provide deidentified individual records and collated data for clinicians and researchers and collated data for families and the general public. This Web-based database will be an invaluable resource for understanding the nature of the disorder and managing children and adults with Rett syndrome. (J Child Neurol 2003;18:709-713). [ABSTRACT FROM AUTHOR]

The etiology of frequently occurring osteoporosis in Rett syndrome is unknown. Five girls, ages 9.75, 11, 12, 13.5, and 14 years, with typical Rett syndrome requiring scoliosis surgery presented an opportunity to study bone remodeling by quantitative bone histomorphometry. Anterior iliac crest bone biopsies token 1 to 2 days after double labeling of the bone surfaces with tetracycline were submitted for histomorphometry. Bone volume was reduced, and the surface parameters of formation (osteoid surface) were normal, whereas the parameters of resorption (osteoclast surface and number) were decreased. In four girls, the rate of bone formation was reduced but could not be measured in one girl owing to poor labeling. It is possible that the slow rate of bone formation impedes the development and accumulation of peak bone mass and contributes to the decreased bone volume in Rett syndrome. Perhaps MECP2 mutations in Rett syndrome not only influence brain development but also affect bone formation. (J Child Neurol 2003;18:698-702). [ABSTRACT FROM AUTHOR]

Compares the heart rate variability between female children affected by classic and atypical Rett syndrome to explain the risk for sudden death in this group. Significantly lower RR interval in children with classic Rett syndrome; Decreased total power spectrum of heart rate variability; Prolonged QT prolongation in patients with classic Rett syndrome.

Autonomic nervous system involvement in female patients with classic Rett syndrome usually manifests as breathing abnormalities, peripheral vasomotor disturbances, and cardiac sympathetic imbalance, the latter a possible cause of sudden death. MECP2 gene mutations responsible for Rett syndrome have also been found in male patients with mental retardation, sometimes associated with different neurologic abnormalities. However, autonomic nervous system functions have never been investigated in male patients with X-linked mental retardation owing to MECP2 mutations. We studied heart rate variability, a marker of autonomic activity, in a family with the MECP2 mutation in male patients, one of whom had died suddenly. Cardiovascular features similar So those observed in a Rett syndrome variant with preserved speech were found, suggesting sympathetic imbalance. (J Child Neurol 2004;19:964-966). [ABSTRACT FROM AUTHOR]