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Deletion analyses of SMN1 and NAIP genes in Malaysian spinal muscular atrophy patients
Author(s) -
WATIHAYATI MOHD S.,
ZABIDIHUSSIN AZHAR M.H.,
TANG THEAN H.,
MATSUO MASAFUMI,
NISHIO HISAHIDE
Publication year - 2007
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/j.1442-200x.2007.02302.x
Subject(s) - smn1 , exon , spinal muscular atrophy , sma* , gene , biology , genetics , medicine , mathematics , combinatorics
Background: The survival motor neuron 1 ( SMN1 ) gene has been recognized to be responsible for spinal muscular atrophy (SMA) because it is homozygously deleted in more than 90% of SMA patients, irrespective of their clinical severity, whereas the neuronal apoptosis inhibitory protein ( NAIP ) gene is now considered to be a modifying factor of the severity of SMA. In Malaysia, it remains to be elucidated whether deletion of the SMN1 gene is also a main cause of SMA or whether deletion of the NAIP gene is found in the SMA patients. Methods: To clarify the pathogenesis of SMA in Malaysia, a deletion analysis of the SMN1 and NAIP genes was performed in 24 Malaysian SMA patients. Deletion analysis of exons 7 and 8 of the SMN1 gene was performed according to the method described by van der Steege et al. , while deletion analysis of exon 5 of the NAIP gene was performed according to a method described by Roy et al. Results: Homozygous deletion of SMN1 exon 7 and exon 8 were identified in 19 out of 24 patients (79%). As to the NAIP gene, deletion of exon 5 was detected in six out of 24 patients (25%). NAIP gene deletion was correlated with severity of the disease. Conclusions: Deletion of the SMN1 exon 7 is a major cause of SMA in Malaysia, and NAIP gene deletions are not rare in type I SMA in Malaysia. The lower percentage of the SMN1 gene deletion may be due to the possibility that the present study included some patients without SMN1 gene abnormality and/or some patients with non‐deletion type mutations in the SMN1 gene.