[Mutation and polymorphism in exon 4 of tuberous sclerosis complex gene].

OBJECTIVE

To study the characteristic of mutation and polymorphism in exon 4 of tuberous sclerosis complex gene(TSC1) in Chinese.

METHODS

Twenty-five TSC patients and 23 parents from 21 families were enrolled. The mutation of exon 4 in these subjects was identified by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and further confirmed by direct sequencing.

RESULTS

The normal controls had the same SSCP bands. In 25 TSC patients, a sporadic case was found to display variant banding pattern and be heterozygous for 352 insA mutation by sequencing. In 23 parents who were normal on clinical examination, another bandshift was found on a mother who had two affected children, which was confirmed as 347A-->C(Val42Val) single nucleotide polymorphism(SNP) by sequencing.

CONCLUSION

The 352 insA mutation is a new causative mutation and the 347A-->C is a rare single nucleotide polymorphism.