Spinal muscular atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Its incidence is approximately 1 in 11,000 live births. In 2007, an International Conference on the Standard of Care for SMA published a consensus statement on SMA standard of care that has been widely used throughout the world. Here we report a two-part update of the topics covered in the previous recommendations. In part 1 we present the methods used to achieve these recommendations, and an update on diagnosis, rehabilitation, orthopedic and spinal management; and nutritional, swallowing and gastrointestinal management. Pulmonary management, acute care, other organ involvement, ethical issues, medications, and the impact of new treatments for SMA are discussed in part 2.

This is the second half of a two-part document updating the standard of care recommendations for spinal muscular atrophy published in 2007. This part includes updated recommendations on pulmonary management and acute care issues, and topics that have emerged in the last few years such as other organ involvement in the severe forms of spinal muscular atrophy and the role of medications. Ethical issues and the choice of palliative versus supportive care are also addressed. These recommendations are becoming increasingly relevant given recent clinical trials and the prospect that commercially available therapies will likely change the survival and natural history of this disease.

Over the past decade there have been major advances in defining the genetic basis of the majority of congenital myopathy subtypes. However the relationship between each congenital myopathy, defined on histological grounds, and the genetic cause is complex. Many of the congenital myopathies are due to mutations in more than one gene, and mutations in the same gene can cause different muscle pathologies. The International Standard of Care Committee for Congenital Myopathies performed a literature review and consulted a group of experts in the field to develop a summary of (1) the key features common to all forms of congenital myopathy and (2) the specific features that help to discriminate between the different genetic subtypes. The consensus statement was refined by two rounds of on-line survey, and a three-day workshop. This consensus statement provides guidelines to the physician assessing the infant or child with hypotonia and weakness. We summarise the clinical features that are most suggestive of a congenital myopathy, the major differential diagnoses and the features on clinical examination, investigations, muscle pathology and muscle imaging that are suggestive of a specific genetic diagnosis to assist in prioritisation of genetic testing of known genes. As next generation sequencing becomes increasingly used as a diagnostic tool in clinical practise, these guidelines will assist in determining which sequence variations are likely to be pathogenic.

The motor skills of patients with spinal muscular atrophy, type I (SMA-I) are very limited. It is difficult to quantify the motor abilities of these patients and as a result there is currently no validated measure of motor function that can be utilized as an outcome measure in clinical trials of SMA-I. We have developed the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (“CHOP INTEND”) to evaluate the motor skills of patients with SMA-I. The test was developed following the evaluation of 26 infants with SMA-I mean age 11.5 months (1.4–37.9 months) with the Test of Infant Motor Performance and The Children’s Hospital of Philadelphia Test of Strength in SMA, a newly devised motor assessment for SMA. Items for the CHOP INTEND were selected by an expert panel based on item mean and standard deviation, item frequency distribution, and Chronbach’s alpha. Intra-rater reliability of the resulting test was established by test–retest of 9 infants with SMA-I over a 2 month period; Intraclass correlation coefficient (ICC) (3,1) = 0.96. Interrater reliability was by video analysis of a mixed group of infants with neuromuscular disease by 4 evaluators; ICC (3,4) = 0.98 and in a group of 8 typically developing infants by 5 evaluators ICC (3,5) = 0.93. The face validity of the CHOP INTEND is supported by the use of an expert panel in item selection; however, further validation is needed. The CHOP INTEND is a reliable measure of motor skills in patients with SMA-I and neuromuscular disorders presenting in infancy.

Aim An international Clinical Outcomes Group consisting of clinicians, scientists, patient advocacy groups, and industries identified a need for a scale to measure motor performance of the upper limb. We report the steps leading to the development of the Performance of the Upper Limb (PUL), a tool specifically designed for assessing upper limb function in ambulant and non‐ambulant patients with Duchenne muscular dystrophy (DMD). Method The development of the PUL followed a number of steps, from the systematic review and a preliminary study exploring the suitability of the existing measures, to the application of a pilot version in a multicentric setting, with Rasch analysis of the preliminary results, leading to a revised pro forma. Results The PUL was specifically designed for DMD, with a conceptual framework reflecting the progression of weakness and natural history of functional decline in DMD. Modern psychometric methods were used to create a scale with robust internal reliability, validity, and hierarchical scalability; males with DMD and their families were involved iteratively throughout the process of the clinician‐reported outcome assessment tool development to establish clinical meaningfulness and relevance of individual PUL items to activities of daily living. Interpretation The module was developed using innovative approaches and will be useful for designing clinical trials.