Date	Event	Description
18 June 2019	New search has been performed	A search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register identified 16 potentially relevant references. A total of 14 references were excluded on title alone and one was an additional reference to the included study (Wraith 2004) and one to an excluded study (Chen 2015). An additional 21 references were identified by a search of clinical trials registries and these were discarded as not relevant. A new summary of findings table has been added to the review and findings from this incorporated into all relevant sections.
18 June 2019	New citation required but conclusions have not changed	The review was updated throughout. Minor changes have been made. Given that there are unlikely to be any trials published in this area, this review will no longer be regularly updated.
5 January 2016	New citation required but conclusions have not changed	Minor changes have been made throughout the review for this update. The 'Plain language summary' was updated in line with the most recent guidelines.
5 January 2016	New search has been performed	A search of the Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register identified 35 references. A total of 30 references were disregarded as they were not relevant to the review. Two were additional references to an included study but included data only on a non‐randomised extension phase of the study (data not included in the review) (Wraith 2004). One was an overview of enzyme replacement therapy (Kakkis 2001b); two were on intrathecal enzyme replacement therapy (Chen 2015; Salehpour 2015).
20 November 2013	New citation required but conclusions have not changed	A P value has been corrected in the abstract section of the review.
20 November 2013	Amended	An amendment has been made to the abstract.