CYP2A6 gene judgment methods

A method for identifying a wild-type a whole deletion-type, or a conversion-type CYP2A6 gene comprising the steps of:

• (a) obtaining genomic DNA containing a CYP2A6 gene from a human being;
• and
• (b) comparing said gene to the wild-type CYP2A6 gene, the whole deletion-type CYP2A6 gene that lacks exon 1-9, and the conversion-type CYP2A6 gene wherein said conversion-type gene contains a substitution of about 60 bp of exon 9 of the CYP2A7 gene in place of the corresponding exon 9 sequences of the CYP2A6 gene,
• wherein if the comparison shows that said CYP2A6 gene is identical to said wild-type gene then said CYP2A6 gene is identified as a wild-type gene;
• and if said comparison shows that said CYP2A6 gene is identical to said whole deletion-type gene, then said CYP2A6 gene is identified as a whole deletion-type gene;
• and if the comparison shows that said CYP2A6 gene is identical to said conversion-type gene then said CYP2A6 gene is identified as a conversion-type gene.

A diagnostic kit for determining a CYP2A6 genotype comprising:

• a 5′-primer that hybridizes to both exon 8 of the CYP2A6 gene and exon 8 of the CYP2A7 gene;
• a 3′-primer that specifically hybridizes to exon 9 of the CYP2A6 gene;
• AccII or an isochizomer thereof;
• and Eco81I or an isochizomer thereof.

A method for determining that a CYP2A6 gene is of the same length as that of a wild-type, a whole deletion-type, or a conversion-type CYP2A6 gene comprising the steps of:

• (a) obtaining genomic DNA containing a CYP2A6 gene from a human being;
• (b) preparing a 5′-primer having the nucleotide sequence of SEQ ID NO:
• 5 and a 3′-primer having the nucleotide sequence of SEQ ID NO:
• 6;
• (c) conducting a PCR using the genomic DNA of step (a) as the template, and the 5′ primer and 3′ primer of step (b);
• (d) digesting the amplified products obtained in step (c) with AccII or an isochizomer thereof and Eco81I or an isochizomer thereof;
• and
• (e) comparing the sizes of the resulting products of step (d) to the sizes of the fragments obtained by digesting with AccII or an isochizomer thereof and Eco81I or an isochizomer thereof the amplified products of the wild-type CYP2A6 gene, and the whole deletion-type CYP2A6 gene that lacks exon 1-9, and the conversion-type CYP2A6 gene wherein said conversion-type gene contains a substitution of about 60 bp of exon 9 of the CYP2A7 gene in place of the corresponding exon 9 sequences of the CYP2A6 gene, which are obtained by conducting a PCR using the wild-type CYP2A6 gene, and the whole deletion-type CYP2A6 gene and the conversion-type CYP2A6 gene as the templates, respectively, and said 5′ primer and 3′-primer of step (b),
• wherein if the comparison shows that said fragments produced from said CYP2A6 gene are identical in size to the fragments produced by said wild-type gene, then said CYP2A6 gene is identified as being the same length as said wild-type gene;
• and if said comparison shows that said fragments produced from said CYP2A6 gene are identical in size to said fragments produced by said whole deletion-type gene, then said CYP2A6 gene is identified as being the same length as said whole deletion-type gene;
• and if the comparison shows that said fragments produced from said CYP2A6 gene are identical in size to said conversion-type gene then said CYP2A6 gene is identified as being the same length as said conversion-type gene.

A method for determining that a CYP2A6 gene is of the same length as that of a wild or mutant type CYP2A6 gene comprising the steps of:

• (a) obtaining genomic DNA containing a CYP2A6 gene from a human being;
• (b) preparing a 5′-primer having the nucleotide sequence of SEQ ID NO:
• 5 and a 3′-primer having the nucleotide sequence of SEQ ID NO:
• 6;
• (c) conducting a PCR using the genomic DNA of step (a) as the template, and the 5′ primer and 3′ primer of step (b);
• (d) digesting the amplified products obtained in step (c) with AccII or an isochizomer thereof and Eco81I or an isochizomer thereof;
• and
• (e) comparing the size of the resulting products of step (d) to the sizes of the fragments obtained by digesting with AccII or an isochizomer thereof and Eco81I or an isochizomer thereof the amplified products of the wild-type CYP2A6 gene which are obtained using the wild-type CYP2A6 gene as a template, and the 5′-primer and 3′-primer of step (b),
• wherein if the comparison shows that said fragments produced from said CYP2A6 gene are identical in size to the fragments produced by said wild-type gene, then said CYP2A6 gene is identified as being the same length as said wild-type gene;
• and if said comparison shows that said fragments produced from said CYP2A6 gene are different in size compared to said fragments produced by said wild-type gene, then said CYP2A6 gene is identified as being the same length as a mutant-type CYP2A6 gene.