Open-labelled study to monitor the effect of an amino acid formula on symptom management in children with spinal muscular atrophy type I: The SMAAF pilot study.

BACKGROUND: An increasing number of families with children who have spinal muscular atrophy (SMA) are incorporating a special amino acid diet into their child's feeding regimens. Characteristics of the diet include high-carbohydrate and low-fat content with added probiotics. However, because of insufficient evidenced-based research, clinicians are unable to prescribe or endorse this diet. Our aim was to assess the tolerability of an adapted version of the traditional amino acid diet in children with SMA type I. METHODS: Children with SMA type I were recruited if they were enterally fed and experienced at least one gastrointestinal symptom (reflux, vomiting, constipation, and/or diarrhea). Children were transitioned to an amino acid formula (Neocate Syneo-Nutricia) for 8 weeks. Feeding tolerance was measured weekly by telephone consultation to monitor reflux, vomiting, stool consistency, and frequency. RESULTS: Fourteen children were recruited, the mean age was 4.1 years (±1.2 SD), and 64% of participants were female. The mean resting energy expenditure determined by indirect calorimetry was 51.5 kcal/kg (±7 SD). The most common gastrointestinal complaint before switching to the amino acid formula was constipation, which was reported in 12 of 14 (85%) patients, of which 10 of the 12 (83%) children required daily stool softeners/laxatives to help regulate bowel function. After 8 weeks on the amino acid formula, 10 out of 12 (83%) children stopped or reduced constipation medication. CONCLUSION: Children with SMA type I who display gastrointestinal symptoms such as constipation and reflux may benefit from an amino acid formula that is fortified with probiotics.

Growth pattern trajectories in boys with Duchenne muscular dystrophy.

OBJECTIVES: The objective of this study is to analyse retrospective, observational, longitudinal growth (weight, height and BMI) data in ambulatory boys aged 5-12 years with Duchenne muscular dystrophy (DMD). BACKGROUND: We considered glucocorticoids (GC) use, dystrophin isoforms and amenability to exon 8, 44, 45, 51 and 53 skipping drug subgroups, and the impact of growth on loss of ambulation. We analysed 598 boys, with 2604 observations. This analysis considered patients from the UK NorthStar database (2003-2020) on one of five regimes: "GC naïve", "deflazacort daily" (DD), "deflazacort intermittent" (DI), "prednisolone daily" (PD) and "prednisolone intermittent" (PI). A random slope model was used to model the weight, height and BMI SD scores (using the UK90). RESULTS: The daily regime subgroups had significant yearly height stunting compared to the GC naïve subgroup. Notably, the average height change for the DD subgroup was 0.25 SD (95% CI - 0.30, - 0.21) less than reference values. Those with affected expression of Dp427, Dp140 and Dp71 isoforms were 0.77 (95% CI 0.3, 1.24) and 0.82 (95% CI 1.28, 0.36) SD shorter than those with Dp427 and/or Dp140 expression affected respectively. Increased weight was not associated with earlier loss of ambulation, but taller boys still ambulant between the age of 10 and 11 years were more at risk of losing ambulation. CONCLUSION: These findings may provide further guidance to clinicians when counselling and discussing GCs commencement with patients and their carers and may represent a benchmark set of data to evaluate the effects of new generations of GC.