|
SMN AND NAIP GENE DELETION IN CHINESE FAMILIES WITH SPINAL MUSCULAR ATROPHY Ma HW1, Gao W2, Xue YN2,
Wang Y1, Guo YY1 1 The Second Clinical
College, China Medical University, Shenyang, China 2 Mineral Hospital, Fuxin,
China Objective: Our purpose was to investigate the frequency of deletions of the
survival moter neurone (SMN) and neuronal apoptosis inhibitory protein (NAIP)
gene in Chinese patients with spinal muscular atrophy (SMA), and the
feasibility of clinical application of detection of deletion of SMN gene in
SMA patients. Methods: Multiple polymerase chain reaction (PCR) or combined restriction
fragment lenth polymophism (RFLP) was used to detect the deletion of exon 7
and exon 8 of SMN gene. And exon 5 of NAIP gene in 35 children with SMA (type
I: 12; type II: 14; type III: 9) and 2 adults with SMA. Prenatal diagnosis of
SMA was performed in 5 cases. Results: Homozygous deletions of SMN exon 7 and exon 8 were identified in
97.1% (34/35) and 74.3% (26/35) of children with SMA, respectively. Homozygous
deletion of the NAIP exon 5 was found in only type I SMA (2/7, 28.6%). No
deletion of SMN or NAIP was found in adult with SMA. Homozygous deletion of
SMN exon 7 was found in one case (1/5) for prenatal diagnosis. Conclusion: The percentage of homozygous deletions of the SMN gene of exon 7 in
Chinese SMA patients with is high. This DNA analysis is paticularly useful in
prenatal diagnosis and confirming the diagnosis of SMA inpatients with
atypical clinical features. Because NAIP gene was deleted mainly in severely
affected patients (type I), NAIP andlysis may be used in prognosing. This
study provides evidence for the non-allelic origin of SMA. |
0186