Parental age effects and Rett syndrome.

Rett syndrome (RTT) is a progressive neurodevelopmental disorder, and pathogenic Methyl-CpG-binding Protein 2 (MECP2) variants are identified in >95% of individuals with typical RTT. Most of RTT-causing variants in MECP2 are de novo and usually on the paternally inherited X chromosome. While paternal age has been reported to be associated with increased risk of genetic disorders, it is unknown whether parental age contributes to the risk of the development of RTT. Clinical data including parental age, RTT diagnostic status, and clinical severity are collected from 1226 participants with RTT and confirmed MECP2 variants. Statistical analyses are performed using Student t-test, single factor analysis of variance (ANOVA), and multi-factor regression. No significant difference is observed in parental ages of RTT probands compared to that of the general population. A small increase in parental ages is observed in participants with missense variants compared to those with nonsense variants. When we evaluate the association between clinical severity and parental ages by multiple regression analysis, there is no clear association between clinical severity and parental ages. Advanced parental ages do not appear to be a risk factor for RTT, and do not contribute to the clinical severity in individuals with RTT.

Anthropometric Measures Correspond with Functional Motor Outcomes in Females with Rett Syndrome.

OBJECTIVE: To characterize growth and anthropometric measurements in females with Rett syndrome and compare these measurements with functional outcomes. STUDY DESIGN: We obtained longitudinal growth and anthropometric measurements from 1154 females with classic and atypical Rett syndrome seen between 2006 and 2019 in the US Natural History Study. We calculated the Clinical Severity Score, Motor Behavior Assessment score, and arm and leg muscle areas and recorded the functional assessments of arm and hand use and ambulation. We compared growth and anthropometric variables from females with Rett syndrome in regard to normative data. We analyzed Clinical Severity Score, Motor Behavior Assessment, and anthropometric measurements in regard to functional assessments. RESULTS: Growth and anthropometric measurements were significantly lower in females with classic and severe atypical Rett syndrome compared with those classified as mild atypical Rett syndrome and deviated from normative patterns among all 3 groups. Suprailiac skinfold measurements correlated with body mass index measurements in each group. Lower leg muscle area measurements were significantly greater among females in all 3 Rett syndrome groups who ambulated independently compared with those who did not. In females with classic Rett syndrome, arm, thigh, and lower leg muscle area measurements increased significantly over time and were significantly greater among those who had purposeful arm and hand use and independent ambulation compared with those who did not. CONCLUSIONS: The pattern of growth and anthropometric measures in females with Rett syndrome differs from normative data and demonstrates clear differences between classic and mild or severe atypical Rett syndrome. Anthropometric measures correspond with functional outcomes and could provide markers supporting efficacy outcomes in clinical trials.

Gastrointestinal Health Questionnaire for Rett Syndrome: Tool Development.

OBJECTIVES: We report the development and validation of a tool to assess gastrointestinal health in Rett syndrome (RTT). We hypothesized that the Gastrointestinal Health Questionnaire (GHQ) is a valid clinical outcomes measure of gastrointestinal health in RTT. PATIENTS AND METHODS: We used parent interviews, surveys, and literature review to generate a questionnaire related to gastrointestinal health and function, mood and behaviors, and parental concerns for individuals with RTT. Parents of affected and unaffected individuals provided responses to the GHQ, assessed the relevance and importance of statements, and completed 5 surveys related to gastrointestinal health, child-related mood and behaviors, and parent concerns. We used multivariate item analysis, 2-sample t tests, and correlations to assess the validity of the GHQ. RESULTS: We documented acceptable internal consistency of statements related to gastrointestinal health and function (Cronbach-α = 0.91), RTT-related mood and behaviors (Cronbach-α = 0.89), and parent concerns (Cronbach-α = 0.95) in the GHQ. We documented favorable external validity based on differences in response scores between parents of affected and unaffected individuals (P < 0.001) and correlations in parental response scores between the GHQ and 5 validated questionnaires addressing similar issues (P < 0.001). CONCLUSION: The GHQ is a valid tool for the assessment of gastrointestinal health in RTT and offers the opportunity to field test the safety and efficacy of novel drug therapies in clinical trials for individuals affected with this disorder.

Growth failure in focal dermal hypoplasia.

Focal dermal hypoplasia (FDH) is a rare genetic disorder caused by mutations in the PORCN gene located on the X chromosome. Short stature was previously noted to be a common finding in FDH, however the etiology of this is unclear. The present study sought to elucidate specific causes for short stature by assessing growth charts, determining bone ages and auxologic measurements, examining laboratory data for the common causes of growth failure, assessing dietary intake, and performing a growth hormone stimulation test. Sixteen patients with FDH between the ages of 3 and 18 years of age consented to the study. While 11 out of 16 patients had short stature based on height less than 2 standard deviations below mid-parental target height percentile and bone age not suggestive of likely catch-up growth, only four had a BMI less than the 5th percentile for age. Laboratory studies did not support a gastrointestinal, allergy or autoimmune cause of growth failure. Three patients had results suggestive of possible growth hormone deficiency. Although short stature is a common feature in FDH, our data suggests that severe undernutrition is not common in this group and that there may be underlying treatable causes for this short stature in some patients.

Biliary Tract Disease in Girls and Young Women With Rett Syndrome.

OBJECTIVE: We reviewed medical records and conducted a nationwide survey to characterize the clinical features and determine the prevalence of biliary tract disease in girls and women with Rett syndrome (RTT). METHODS: Sixty-two individuals with RTT and biliary tract disease were identified from the membership of Rett Syndrome Organization and patient files of the principal investigator. Medical records of 46 individuals were reviewed for presenting features, diagnostic tests, and treatment outcomes of biliary tract disease. We designed a questionnaire that probed the frequency of risk factors and treatment outcomes of biliary tract disease in RTT. The questionnaire was completed by 271 parents whose daughters met the clinical criteria for RTT and/or had MECP2 mutations and participated in the Natural History of Rett Syndrome Study. RESULTS: Presenting symptoms identified by record review included abdominal pain (94%), irritability (88%), weight loss (64%), and vomiting (52%). Biliary dyskinesia, cholecystitis, and cholelithiasis were identified in 90%, 77%, and 70%, respectively, by cholescintigraphy, surgical pathology, and abdominal ultrasound. The prevalence of biliary tract disease was 4.4% (n = 12) in the RTT cohort. Risk factors included older age (P < 0.001) and a positive family history (P < 0.01). Diagnoses included cholecystitis (n = 5), biliary dyskinesia (n = 6), and cholelithiasis (n = 7). Ten individuals underwent surgery; 7 had resolution of symptoms after surgical intervention. CONCLUSIONS: Biliary tract disease is not unique to RTT, but may be under-recognized because of the cognitive impairment of affected individuals. Early diagnostic evaluation and intervention may improve the health and quality of life of individuals affected with RTT and biliary tract disease.

Longitudinal course of epilepsy in Rett syndrome and related disorders.

Epilepsy is common in Rett syndrome, an X-linked dominant disorder caused by mutations in the MECP2 gene, and in Rett-related disorders, such as MECP2 duplication. However, neither the longitudinal course of epilepsy nor the patterns of seizure onset and remission have been described in Rett syndrome and related conditions. The present study summarizes the findings of the Rett syndrome Natural History study. Participants with clinical Rett syndrome and those with MECP2 mutations without the clinical syndrome were recruited through the Rett Natural History study from 2006 to 2015. Clinical details were collected, and cumulative lifetime prevalence of epilepsy was determined using the Kaplan-Meier estimator. Risk factors for epilepsy were assessed using Cox proportional hazards models. Of 1205 participants enrolled in the study, 922 had classic Rett syndrome, and 778 of these were followed longitudinally for 3939 person-years. The diagnosis of atypical Rett syndrome with a severe clinical phenotype was associated with higher prevalence of epilepsy than those with classic Rett syndrome. While point prevalence of active seizures ranged from 30% to 44%, the estimated cumulative lifetime prevalence of epilepsy using Kaplan-Meier approached 90%. Specific MECP2 mutations were not significantly associated with either seizure prevalence or seizure severity. In contrast, many clinical features were associated with seizure prevalence; frequency of hospitalizations, inability to walk, bradykinesia, scoliosis, gastrostomy feeding, age of seizure onset, and late age of diagnosis were independently associated with higher odds of an individual having epilepsy. Aggressive behaviour was associated with lower odds. Three distinct patterns of seizure prevalence emerged in classic Rett syndrome, including those who did not have seizures throughout the study, those who had frequent relapse and remission, and those who had relentless seizures. Although 248 of those with classic Rett syndrome and a history of seizures were in terminal remission at last contact, only 74 (12% of those with a history of epilepsy) were seizure free and off anti-seizure medication. When studied longitudinally, point prevalence of active seizures is relatively low in Rett syndrome, although lifetime risk of epilepsy is higher than previously reported. While daily seizures are uncommon in Rett syndrome, prolonged remission is less common than in other causes of childhood onset epilepsy. Complete remission off anti-seizure medications is possible, but future efforts should be directed at determining what factors predict when withdrawal of medications in those who are seizure free is propitious.

Growth, nutritional, and gastrointestinal aspects of focal dermal hypoplasia (Goltz-Gorlin syndrome).

Focal dermal hypoplasia (FDH) is a rare genetic disorder caused by mutations in the PORCN gene located on the X-chromosome. In the present study, we characterized the pattern of growth, body composition, and the nutritional and gastrointestinal aspects of children and adults (n = 19) affected with this disorder using clinical anthropometry and a survey questionnaire. The mean birth length (P < 0.06) and weight (P < 0.001) z-scores of the participants were lower than the reference population. The mean head circumference (P < 0.001), height (length) (P < 0.001), weight (P < 0.01), and BMI (P < 0.05) for age z-scores of the participants were lower than the reference population. The height-for-age and weight-for-age z-scores of the participants did not differ significantly between birth and current measurements. Three-fourths of the group reported having one or more nutritional or gastrointestinal problems including short stature (65%), underweight (77%), oral motor dysfunction (41%), gastroesophageal reflux (24%), gastroparesis (35%), and constipation (35%). These observations provide novel clinical information about growth, body composition, and nutritional and gastrointestinal aspects of children and adults with FDH and underscore the importance of careful observation and early clinical intervention in the care of individuals affected with this disorder.

Methyl-CpG-binding protein 2 (MECP2) mutation type is associated with disease severity in Rett syndrome.

BACKGROUND: Rett syndrome (RTT), a neurodevelopmental disorder that primarily affects girls, is characterised by a period of apparently normal development until 6-18 months of age when motor and communication abilities regress. More than 95% of individuals with RTT have mutations in methyl-CpG-binding protein 2 (MECP2), whose protein product modulates gene transcription. Surprisingly, although the disorder is caused by mutations in a single gene, disease severity in affected individuals can be quite variable. To explore the source of this phenotypic variability, we propose that specific MECP2 mutations lead to different degrees of disease severity. METHODS: Using a database of 1052 participants assessed over 4940 unique visits, the largest cohort of both typical and atypical RTT patients studied to date, we examined the relationship between MECP2 mutation status and various phenotypic measures over time. RESULTS: In general agreement with previous studies, we found that particular mutations, such as p.Arg133Cys, p.Arg294X, p.Arg306Cys, 3° truncations and other point mutations, were relatively less severe in both typical and atypical RTT. In contrast, p.Arg106Trp, p.Arg168X, p.Arg255X, p.Arg270X, splice sites, deletions, insertions and deletions were significantly more severe. We also demonstrated that, for most mutation types, clinical severity increases with age. Furthermore, of the clinical features of RTT, ambulation, hand use and age at onset of stereotypies are strongly linked to overall disease severity. CONCLUSIONS: We have confirmed that MECP2 mutation type is a strong predictor of disease severity. These data also indicate that clinical severity continues to become progressively worse regardless of initial severity. These findings will allow clinicians and families to anticipate and prepare better for the needs of individuals with RTT.

Low bone mineral mass is associated with decreased bone formation and diet in girls with Rett syndrome.

OBJECTIVE: The aim of the present study was to characterize biomarkers of bone turnover and their relation with bone mineral mass in a cross-sectional cohort of girls with Rett syndrome (RTT) and to examine the role of dietary, biochemical, hormonal, and inflammatory factors on bone mineral mass and bone biomarkers in this disorder. METHODS: Total body bone mineral content (BMC) and bone mineral density (BMD) were determined by dual-energy x-ray absorptiometry. Dietary nutrient intakes were determined from 3-day food records. Biomarkers of bone turnover, bone metabolites, vitamin D metabolites, hormones, and inflammatory markers were measured by standard clinical laboratory methods. RESULTS: Serum osteocalcin, bone alkaline phosphatase, and C-telopeptide showed significant inverse relations with age in the RTT cohort. Mean osteocalcin concentrations were significantly lower and mean bone alkaline phosphatase concentrations were significantly higher for individual age groups in the RTT cohort than mean values for their respective age ranges in the reference population. Significant inverse associations were identified between urinary calcium losses, expressed as calcium:creatinine ratios, and total body BMC and BMD z scores. Dietary protein, calcium, and phosphorus intakes, expressed as a proportion of Dietary Reference Intakes for age and sex, showed significant positive associations with total body BMD z scores. CONCLUSIONS: The present study suggests decreased bone formation instead of increased bone resorption may explain in part the deficits in bone mineral mass in RTT and that attention to the adequacy of dietary protein, calcium, and phosphorus intakes may offer an opportunity to improve bone health in RTT.

Recommendations for the management of gastrointestinal comorbidities with or without trofinetide use in rett syndrome.

INTRODUCTION: Although gastrointestinal (GI) comorbidities are experienced by over 90% of individuals with Rett syndrome (RTT), a neurodevelopmental disorder associated with mutations in the MECP2 gene, many neurologists and pediatricians do not rank the management of these comorbidities among the most important treatment goals for RTT. Trofinetide, the first approved pharmacologic treatment for RTT, confers improvements in RTT symptoms but is associated with adverse GI events, primarily diarrhea and vomiting. Treatment strategies for GI comorbidities and drug-associated symptoms in RTT represent an unmet clinical need. AREAS COVERED: This perspective covers GI comorbidities experienced by those with RTT, either with or without trofinetide treatment. PubMed literature searches were undertaken on treatment recommendations for the following conditions: constipation, diarrhea, vomiting, aspiration, dysphagia, gastroesophageal reflux, nausea, gastroparesis, gastritis, and abdominal bloating. EXPERT OPINION: The authors recommend a proactive approach to management of symptomatic GI comorbidities and drug-associated symptoms in RTT to enhance drug tolerance and improve the quality of life of affected individuals. Management strategies for common GI comorbidities associated with RTT are reviewed based on authors' clinical experience and augmented by recommendations from the literature.

Development and validation of parent-reported gastrointestinal health scale in MECP2 duplication syndrome.

BACKGROUND/AIMS: We aimed to develop a validated patient-reported Gastrointestinal Health Scale (GHS) specific to MECP2 Duplication Syndrome (MDS) to be used in clinical trials. METHODS: MDS parents completed a Gastrointestinal Health Questionnaire (GHQ) to investigate the most relevant and important items associated with gastrointestinal problems in MECP2-related disorders. Item reduction was executed according to EORTC guidelines. We performed reliability and validity studies for the finalized scale. RESULTS: A total of 106 surveys were eligible for item reduction and validation processes. The initial 55 items were reduced to 38 items based on parent responses, expert opinion, and initial confirmatory factor analysis (CFA). The final MDS-specific GHS included 38 items and 7 factors that underwent further reliability and validity assessments. The power of the study was at least 0.982. The Cronbach's alphas of the instruments were General Health: 0.799, Eating-Chewing-Swallowing: 0.809, Reflux: 0.794, Motility: 0.762, Mood: 0.906, Medication: 0.595, Parenting: 0.942 and all items together: 0.928. The correlation coefficient between total and individual item scores ranged from 0.215 to 0.730. Because of the ordinal nature of the variables, the diagonal weighted least squares estimation (DWLS) method was used to execute the CFA and Structural Equation Modeling. The GHS had excellent model fit with the acceptable range of fit indices values. CONCLUSIONS: We developed a parent-reported, reliable, and valid MDS-specific GHS. This scale can be utilized in clinical settings or as an outcome measure in translational and clinical research.

Detection of rarely identified multiple mutations in MECP2 gene do not contribute to enhanced severity in Rett syndrome.

The objective of our study was to characterize the influence of multiple mutations in the MECP2 gene in a cohort of individuals with Rett syndrome. Further analysis demonstrated that nearly all resulted from de novo in cis mutations, where the disease severity was indistinguishable from single mutations. Our methods involved enrolling participants in the RTT Natural History Study (NHS). After providing informed consent through their parents or principal caretakers, additional molecular assessments were performed in the participants and their parents to assess the presence and location of more than one mutation in each. Clinical severity was assessed at each visit in those participants in the NHS. Non-contiguous MECP2 gene variations were detected in 12 participants and contiguous mutations involving a deletion and insertion in three participants. Thirteen of 15 participants had mutations that were in cis; four (of 13) had three MECP2 mutations; two (of 15) had mutations that were both in cis and in trans (i.e., on different alleles). Clinical severity did not appear different from NHS participants with a single similar mutation. Mutations in cis were identified in most participants; two individuals had mutations both in cis and in trans. The presence of multiple mutations was not associated with greater severity. Nevertheless, multiple mutations will require greater thought in the future, if genetic assignment to drug treatment protocols is considered.

Exploring gastrointestinal health in MECP2 duplication syndrome.

BACKGROUND: MECP2 duplication syndrome (MDS) is a rare neurogenetic syndrome caused by duplications of MECP2 at the Xq28 region. Although constipation and gastrointestinal reflux are reported in MDS, a comprehensive characterization of gastrointestinal health has not been fully explored. METHODS: We conducted a parent survey to explore the characteristics of gastrointestinal health in individuals with MDS using a secure online registry and compared differences in gastrointestinal symptoms between individuals with MDS and those with Rett syndrome (RTT). KEY RESULTS: One hundred six surveys were analyzed. Symptoms commonly associated with constipation occurred in 72% to 89% of MDS individuals. Eleven percent of MDS individuals underwent surgery for complications associated with constipation. We observed a bimodal distribution for gastroesophageal reflux disease (GERD) and gastrostomy feeding, with higher prevalence in 0-3 and >12-year-old MDS individuals. Constipation and GERD were significantly more common, and gas bloating was significantly less common in MDS than in RTT. Biliary tract disease requiring surgery was an unrecognized problem in 5% of MDS individuals. We determined that gastrointestinal problems in MDS individuals contribute to caretaker burden. CONCLUSION AND INFERENCES: Our study is the first in-depth investigation that characterizes gastrointestinal health in MDS and enumerates differences in gastrointestinal symptoms between MDS and RTT. Strategies to reduce gastrointestinal symptoms will alleviate caregiver burden in MDS. Further studies are needed to examine the mechanisms that cause gastrointestinal problems in MDS.

Prevalence of atopic disorders and immunodeficiency in patients with ectodermal dysplasia syndromes.

BACKGROUND: Ectodermal dysplasia (ED) syndromes are a diverse group of disorders that affect multiple ectodermally derived tissues. Small studies and case reports suggest an increase in atopy and primary immunodeficiencies (PIDs) among patients with ED syndromes. OBJECTIVE: To determine the prevalence of clinical symptoms suggestive of atopy or immunodeficiency among a large cohort of children with ED syndromes. METHODS: A 9-page questionnaire was mailed to families who were members of the National Foundation for Ectodermal Dysplasias. The surveys were completed by parents of children younger than 18 years with a diagnosis of an ED syndrome or carrier state. Portions of the questionnaire were adapted from previously validated questionnaires developed by the International Study of Asthma and Allergies in Childhood (ISAAC). RESULTS: We received 347 completed questionnaires (41%). When compared with the 13- to 14-year-old children surveyed by ISAAC, we found both all-aged and age-matched children with ED syndromes, respectively, had significantly higher rates of asthma (32.2% and 37.2% vs 16.4%), rhinitis symptoms (76.1% and 78.3% vs 38.9%), and eczema (58.9% and 48.9% vs 8.2%). The prevalence of physician-diagnosed food allergies (20.7%) and PIDs (6.1%) in these ED patients also exceeded known rates in the general pediatric population. CONCLUSION: This large-scale, retrospective study demonstrates a greater reported prevalence of symptoms suggestive of atopic disorders and PIDs among children with ED syndromes than the general pediatric population. A combination of genetic and environmental factors in ED syndromes may contribute to breaches of skin and mucosal barriers, permitting enhanced transmission and sensitization to irritants, allergens, and pathogens.

Gastrointestinal and nutritional problems occur frequently throughout life in girls and women with Rett syndrome.

OBJECTIVE: We conducted a nationwide survey to determine the prevalence of common gastrointestinal and nutritional disorders in Rett syndrome (RTT) based on parental reporting and related the occurrence of these problems to age and methyl-CpG-binding protein 2 (MECP2) gene status. METHODS: We designed a questionnaire that probed symptoms, diagnoses, diagnostic tests, and treatment interventions related to gastrointestinal and nutritional problems in RTT. The International Rett Syndrome Foundation distributed the questionnaire to 1666 family-based members and forwarded their responses for our review. We interrogated the Rare Disease Clinical Research Network database to supplement findings related to medications used to treat gastrointestinal problems in RTT. RESULTS: Parents of 983 female patients with RTT (59%) responded and identified symptoms and diagnoses associated with gastrointestinal dysmotility (92%), chewing and swallowing difficulties (81%), weight deficits or excess (47%), growth deficits (45%), low bone mineral content or fractures (37%), and biliary tract disorders (3%). Height-for-age, weight-for-age, and body mass index z scores decreased significantly with age; height- and weight-, but not body mass index-for-age z scores were significantly lower in female subjects with MECP2 mutations than in those without. Vomiting, nighttime awakening, gastroesophageal reflux, chewing difficulty, and choking with feeding were significantly less likely to occur with increasing age. Short stature, low bone mineral content, fractures, and gastrostomy placement were significantly more likely to occur with increasing age. Chewing difficulty, choking with feeding, and nighttime awakening were significantly less likely to occur, whereas short stature was significantly more likely to occur, in female subjects with MECP2 mutations than in those without. Diagnostic evaluations and therapeutic interventions were used less frequently than the occurrence of symptoms or diagnoses in the RTT cohort. CONCLUSIONS: Gastrointestinal and nutritional problems perceived by parents are prevalent throughout life in girls and women with RTT and may pose a substantial medical burden for their caregivers. Physician awareness of these features of RTT may improve the health and quality of life of individuals affected with this disorder.

Potocki-Lupski syndrome: a microduplication syndrome associated with oropharyngeal dysphagia and failure to thrive.

OBJECTIVE: Failure to thrive (FTT) is a feature of children with Potocki-Lupski syndrome (PTLS) [duplication 17p11.2]. This study was designed to describe the growth characteristics of 24 subjects with PTLS from birth through age 5 years in conjunction with relevant physical features and swallow function studies. STUDY DESIGN: We evaluated 24 individuals with PTLS who were ascertained by chromosome analysis and/or array comparative genome hybridization. Clinical assessments included review of medical records, physical examination, otolaryngological examination, and swallow function studies. Measures of height and weight were converted to Z-scores. RESULTS: The mean weight-for-age and weight-for-length Z-scores at birth were lower (P < .01) than the reference standard and did not change with age. A history of poor feeding, hypotonia, and FTT were reported in 92%, 88%, and 71%, respectively. Individuals with hypotonia had lower weight-for-age and body mass index-for-age Z-scores (P = .01). Swallow function studies demonstrated at least one abnormality in all subjects. CONCLUSIONS: FTT is common in children with PTLS. We hypothesize that oropharyngeal dysphagia and hypotonia likely contribute to FTT in patients with PTLS and recommend that once a diagnosis is established, the individual be assessed for feeding and growth issues and be availed of oromotor therapy and nutritional services.

Rett syndrome diagnostic criteria: lessons from the Natural History Study.

Analysis of 819 participants enrolled in the Rett syndrome (RTT) Natural History Study validates recently revised diagnostic criteria. 765 females fulfilled 2002 consensus criteria for classic (653/85.4%) or variant (112/14.6%) RTT. All participants classified as classic RTT fulfilled each revised main criterion; supportive criteria were not uniformly present. All variant RTT participants met at least 3 of 6 main criteria in the 2002, 2 of 4 main criteria in the current format, and 5 of 11 supportive criteria in both. This analysis underscores the critical role of main criteria for classic RTT; variant RTT requires both main and supportive criteria.

Vitamin D deficiency is prevalent in girls and women with Rett syndrome.

OBJECTIVES: The aim of the study was to determine the prevalence of vitamin D deficiency and identify the relation between 25-hydroxyvitamin D (25-(OH)D) levels and the consumption of dietary sources of vitamin D or exposure to anticonvulsants in girls and women with Rett syndrome (RTT). SUBJECTS AND METHODS: Retrospective review of the medical records of 284 girls and women with RTT to determine serum 25-(OH)D and parathyroid hormone levels, nutritional status, dietary sources of vitamin D, exposure to anticonvulsants, degree of mobility, and MECP2 status. RESULTS: Twenty percent of girls and women who were tested (n = 157) had 25-(OH)D levels <50 nmol/L. Multivitamin supplements, vitamin D-fortified milk, and commercial formulas were consumed by 40%, 52%, and 54%, respectively. Anticonvulsants were used by 57%, and 39% ambulated independently. Median 25-(OH)D levels were lower in individuals who did not receive multivitamin supplements (P < 0.05) or commercial formulas (P < 0.001) than in those who did. Median 25-(OH)D levels differed (P < 0.01) among racial and ethnic groups, but the number in some groups was small. Nutritional status, use of anticonvulsants, degree of mobility, and MECP2 status did not influence 25-(OH)D levels. CONCLUSIONS: Vitamin D deficiency is prevalent in girls and women with RTT. The use of multivitamin supplements or commercial formulas is associated with improved vitamin D levels. Attention to vitamin D may enhance bone mineral deposition and reduce the frequency of bone fractures in these individuals.

Simple Energy Balance or Microbiome for Childhood Obesity Prevention?

Obesity prevention interventions generally have either not worked or had effects inadequate to mitigate the problem. They have been predicated on the simple energy balance model, which has been severely questioned by biological scientists. Numerous other etiological mechanisms have been proposed, including the intestinal microbiome, which has been related to childhood obesity in numerous ways. Public health research is needed in regard to diet and the microbiome, which hopefully will lead to effective child obesity prevention.