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.
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mdor na grong pa sgo gcig gi mdo phran gcig 'bri bar mi gda' zhing / drung gi phyag dpe lags pas kun gyis gzab pa gal che'o // zhabs thog rnams kyang 'bad pa chen pos sgrub cing / phyis yon rdzong rnams kyang bzang por yon tan la ji ltar 'os pa bzhin zhu ba bgyid pa lags pas kun gyis gzab pa gal che'o // gal che'o // subham //.
2-5: dgung lo brgyad cu bgrangs pa dang /mdo khams kyi khams pa gnyis kyis gdams ngag zhus nas/ don thams cad rdzogs pa dang / da dpe gnang bar zhus pas/ sgros 'dogs gcod pa don gyi rgyud pa la/ yig chung gi lhad ma zhugs pa zhig dgos pa yin/ nga la yi ge ka tsam zhig yod re gsungs nas dbu bsnyung bzhes/ phyis yang ston gyis yi ger 'debs par zhu ba phul/ nan bskyed nas yang yang zhus pas/ 'bri mkhan gsum gyi bla ma'i thugs la bris pas zhag nyi shu'i khongs su 'bri rgyu byung / de nas dbu bzung nas dpon sras rnams kyis kyang / brjed tho than thun yig chung du zhus nas bkod pa yang gda'o/.