spinal muscular atrophy type 1


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spinal muscular atrophy type 1

An autosomal recessive condition (OMIM:253300) characterised by degeneration of the anterior horn cells of the spinal cord, leading to symmetrical muscle weakness and atrophy. Disease severity is inversely proportional to the copy number of SMN2, a copy gene which predominantly produces exon 7-skipped transcripts and only low amounts of full-length transcripts that encode for a protein identical to SMN1. Only about 4% of SMA patients bear one SMN1 copy with an intragenic mutation. SMA1 is the severest form of the SMAs, with onset before age 6 months. Infants never achieve the ability to sit.

Molecular pathology
Defects of SMN1, which encodes a survival motor neuron protein, cause spinal muscular atrophy types 1–4.
References in periodicals archive ?
Current statistics show an 8-month average lifespan for a child born with spinal muscular atrophy Type 1 who is not put on a ventilator, according to Ms.
Comorbid conditions were present in 22 children: cystic fibrosis (1), spinal muscular atrophy type 1 (4), Down syndrome (4), cardiac abnormalities (5), and HIV infection (8).
April 18 /PRNewswire/ -- Lisa's 4-year-old son Billy has Spinal Muscular Atrophy Type 1, a disease that has minimized his movement and muscle control, leaving him with just the slightest movement in his hands.

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