Distal spinal muscular atrophy type 1 (DSMA1), also known as spinal muscular atrophy with respiratory distress type 1 (SMARD1), is a rare neuromuscular disorder involving death of motor neurons in the spinal cord which leads to a generalised progressive atrophy of body muscles. The condition is caused by a genetic mutation in the IGHMBP2 gene and is inherited in an autosomal recessive manner. There is no known cure to DSMA1, and research of the disorder is still in early stages due to low incidence and high mortality rates. Signs and symptoms
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. 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. Due to the severe nature of diaphragmatic paralysis, the patient eventually needs continuous ventilation support to survive. Continuous ventilation, however, may in itself cause damage to the anatomy of the lungs.In addition to diaphragmatic paralysis, other issues may arise: as the name suggests, the distal limbs are most affected with symptoms of weakness, restricting mobility due to (near-)paralysis of the distal limbs as well as the head and neck. Also, dysfunction of the peripheral nerves and the autonomic nervous system may occur. Due to these dysfunctions, the patients have been shown to suffer from excessive sweating and irregular heartbeat.
The discrepancies in the practitioners’ knowledge, family resources, and differences in patients culture and/or residency have played a part in the outcome of the patient. Prognosis
DSMA1 is usually fatal in early childhood. The patient, normally a child, suffers a progressive degradation of the respiratory system until respiratory failure. There is no consensus on the life expectancy in DSMA1 despite a number of studies being conducted. 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. Research directions
The disease has only been identified as distinct from SMA recently, so research is still experimental, taking place mostly in animal models. Several therapy pathways have been devised which include gene therapy, whereby an IGHMBP2 transgene is delivered to the cell using a viral vector, and small-molecule drugs like growth factors (e.g., IGF-1 and VEGF) or olesoxime. Studies in amyotrophic lateral sclerosis are also considered helpful because the condition is relatively similar to DSMA1. See also
Distal hereditary motor neuropathies
Spinal muscular atrophies
Spinal muscular atrophy

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