Screening of the LIX1 gene in Japanese and Malaysian patients with SMA and/or SMA-like disorder.

BACKGROUND

The majority of spinal muscular atrophy (SMA) patients showed homozygous deletion or other mutations of SMN1. However, the genetic etiology of a significant number of SMA patients has not been clarified. Recently, mutation in the gene underlying cat SMA, limb expression 1 (LIX1), has been reported. Similarity in clinical and pathological features of cat and human SMA may give an insight into possible similarity of the genetic etiology.

PATIENTS AND

METHODS

In this study, we screened for a mutation in LIX1 using direct DNA sequencing in our SMA and/or SMA-like patients who retained SMN1. A total of 33 patients were enrolled in this study, of which 22 were Japanese and 11 were Malaysians. All these patients possessed at least two copies of SMN1.

RESULTS

We did not identify any pathogenic mutations in the coding regions or splice sites of LIX1 in the patients. In addition, we described a polymorphism within LIX1 intron 3, c.387+107A>T. We found that A-allele is significantly more frequent in SMA patients compared to normal individuals.

CONCLUSION

Molecular genetic analysis of our SMA and/or SMA-like patients suggests that LIX1 is not associated with the development of their disorders. However, the number of patients analyzed in this study was very limited, and a larger study with bigger sample size is needed to confirm this result.