Subtle mutation analysis of survival motor neuron gene in families with spinal muscular atrophy / 中华检验医学杂志

ABSTRACT

ObjectiveTo establish a analytical system for the survival motor neuron (SMN) subtle mutation,and evaluate its application in two families with spinal muscular atrophy (SMA).MethodsSMN genes in seven family members from two SMA families were analyzed at both transcript level and genomic level,by the use of the conventional PCR-RFLP,allele-specific PCR,multiplex ligation-dependent probe amplification (MLPA) and T subcloning and sequencing of SMNI gene.ResultsIn family A,the patient had a single SMN1 copy who was carrying nonsense mutation L228X,which was also found in his father.In family B,as the patient's sample was unavailable,the father was indeed a carrier with one normal SMN1 allele and the other SMN1 allele carrying a frameshift mutation 22_23insA.The remaining family members were SMA carriers with one SMN1 copy.ConclusionThis analytical system for SMN subtle mutation offers viable molecular basis for genetic counseling and prenatal diagnosis in SMA families.