ABSTRACT. Objectives. Diminished bone density and a propensity to fracture with minimal trauma are common in children and adolescents with moderate to severe cerebral palsy (CP). The purpose of this study was to provide a detailed evaluation of bone mineral density (BMD) and metabolism in this population and to assess the relationship of these measures to multiple other clinical, growth, and nutrition variables.Methods. The study group consisted of 117 subjects ages 2 to 19 years (mean: 9.7 years) with moderate to severe CP as defined by the Gross Motor Functional Classification scale. Population-based sampling was used to recruit 62 of the participants, which allows for estimations of prevalence. The remaining 55 subjects were a convenience sampling from both hospital-and school-based sources. The evaluation included measures of BMD, a detailed anthropometric assessment of growth and nutritional status, medical and surgical history, the Child Health Status Questionnaire, and multiple serum analyses. BMD was measured in the distal femur, a site specifically developed for use in this contracted population, and the lumbar spine. BMD measures were converted to age and gender normalized z scores based on our own previously published control series (n > 250).Results. Osteopenia (BMD z score <؊2.0) was found in the femur of 77% of the population-based cohort and in 97% of all study participants who were unable to stand and were older than 9 years. BMD was not as low in the lumbar spine (population-based cohort mean ؎ standard error z score: ؊1.8 ؎ 0.1) as in the distal femur (mean z score: ؊3.1 ؎ 0.2). Fractures had occurred in 26% of the children who were older than 10 years. Multiple clinical and nutritional variables correlated with BMD z scores, but interpretation of these findings is complicated by covariance among variables. In stepwise regression analyses, it was found that severity of neurologic impairment as graded by Gross Motor Functional Classification level, increasing difficulty feeding the child, use of anticonvulsants, and lower triceps skinfold z scores (in decreasing order of importance) all independently contribute to lower BMD z scores in the femur.Conclusions. Low BMD is prevalent in children with moderate to severe CP and is associated with significant fracture risk. The underlying pathophysiology is complex, with multiple factors contributing to the problem and significant variation between different regions of the skeleton. Pediatrics 2002;110(1). URL: http://www. pediatrics.org/cgi/content/full/110/1/e5; cerebral palsy, bone mineral density, osteoporosis, pediatrics, bone metabolism, growth, nutrition, osteopenia.

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Lung transplantation with its attendant life-long immunosuppression contributes to bone loss and its sequelae, fractures and kyphosis, in patients with lung disease, many of whom already suffer from severe osteoporosis. Patients with cystic fibrosis (CF) are one of the most severely affected groups. We conducted a controlled, randomized, nonblinded trial of pamidronate (30 mg intravenously every 3 mo) with vitamin D (800 IU/d) and calcium (1 g/d) (n = 16) compared with vitamin D and calcium alone (n = 18, the control subjects) for 2 yr in 34 patients after lung transplant to improve bone mineral density (BMD). The treatment groups were similar in age, sex, baseline T-scores, renal function, hospitalization rates, immunosuppressant levels, change in lung function, and body mass index (BMI) over the study period. The patients treated with pamidronate gained 8.8 +/- 2.5% and 8.2 +/- 3.8% in spine and femur BMD after 2 yr in comparison to control subjects, who gained, on average (+/- SD), 2.6 +/- 3.2 and 0.3 +/- 2.2%, respectively (p 0.2). Measures of bone resorption were highest immediately after lung transplant and improved with both pamidronate and time. Measures of bone formation were very poor after lung transplant, but recovered in the first post-lung transplant year irrespective of therapy. We conclude that pamidronate was more effective than control in improving bone mineral density after lung transplantation in patients with CF and appears to be one of the most promising agents studied to date for posttransplant osteoporosis.

Interferon regulatory factor 2 binding protein-like (IRF2BPL) encodes a member of the IRF2BP family of transcriptional regulators. Currently the biological function of this gene is obscure, and the gene has not been associated with a Mendelian disease. Here we describe seven individuals who carry damaging heterozygous variants in IRF2BPL and are affected with neurological symptoms. Five individuals who carry IRF2BPL nonsense variants resulting in a premature stop codon display severe neurodevelopmental regression, hypotonia, progressive ataxia, seizures, and a lack of coordination. Two additional individuals, both with missense variants, display global developmental delay and seizures and a relatively milder phenotype than those with nonsense alleles. The IRF2BPL bioinformatics signature based on population genomics is consistent with a gene that is intolerant to variation. We show that the fruit-fly IRF2BPL ortholog, called pits (protein interacting with Ttk69 and Sin3A), is broadly detected, including in the nervous system. Complete loss of pits is lethal early in development, whereas partial knockdown with RNA interference in neurons leads to neurodegeneration, revealing a requirement for this gene in proper neuronal function and maintenance. The identified IRF2BPL nonsense variants behave as severe loss-of-function alleles in this model organism, and ectopic expression of the missense variants leads to a range of phenotypes. Taken together, our results show that IRF2BPL and pits are required in the nervous system in humans and flies, and their loss leads to a range of neurological phenotypes in both species.