[1] Usually, the first respiratory symptoms are shortness of breath (dyspnea) and paradoxical respirations which then escalate within the first few months of life to diaphragmatic paralysis.

[2] The symptoms of diaphragmatic paralysis come on very rapidly and without warning, and the patient is often rushed to a hospital where they are placed on a ventilator for respiratory support.

[3] Due to the severe nature of diaphragmatic paralysis, the patient eventually needs continuous ventilation support to survive.

[2] DSMA1 is caused by a genetic mutation in the IGHMBP2 gene (located on chromosome 11, locus 11q13.3), which codes the immunoglobulin helicase μ-binding protein 2.

Non-ambulant patients may develop pressure ulcers, severe constipation, urinary incontinence, and (rarely) reflux nephropathy in the advanced stages of the disease.

[citation needed] Although the patient may have a variety of other symptoms, the diaphragmatic palsy confirmed by fluoroscopy or other means is the main criteria for diagnosis.

[3] Currently, various classifications include DSMA1 either among spinal muscular atrophies or among distal hereditary motor neuropathies, though the latter has been argued to be more correct.

A small number of patients survive past two years of age but they lack signs of diaphragmatic paralysis or their breathing is dependent on a ventilation system.

[1] The disease has only been identified as distinct from SMA recently, so research is still experimental, taking place mostly in animal models.