Gene causative of rothmund-thomson syndrome and gene product

Abstract

The RecQ4 helicase gene, belonging to the RecQ helicase gene family, is revealed herein to be the causative gene of Rothmund-Thomson syndrome. The present inventors found out that it is possible to diagnose Rothmund-Thomson syndrome by detecting mutation of this gene. Further, they uncovered that it is possible to treat patients of Rothmund-Thomson syndrome by utilizing normal RecQ4 helicase gene or proteins thereof.

1 . A genomic DNA encoding RecQ4 helicase.  
     
     
         2 . A vector comprising the genomic DNA of  claim 1 .  
     
     
         3 . A host cell containing the vector of  claim 2 .  
     
     
         4 . A DNA used for the diagnosis of Rothmund-Thomson syndrome, which hybridizes to a DNA encoding the RecQ4 helicase or the expression regulatory region thereof and has a chain length of at least 15 nucleotides.  
     
     
         5 - 14 . (Cancelled)  
     
     
         15 . A method for the diagnosis of Rothmund-Thomson syndrome, characterized by detecting mutations in the DNA encoding RecQ4 helicase or the expression regulatory region thereof.  
     
     
         16 . The method for the diagnosis of Rothmund-Thomson syndrome in  claim 15  comprising the steps of: 
 (a) preparing DNA samples from patients;  
 (b) amplifying the prepared DNA samples using the DNA of  claim 4  as a primer and determining the base sequence; and  
 (c) comparing the determined base sequence with that of a healthy normal person.  
 
     
     
         17 . The method for the diagnosis of Rothmund-Thomson syndrome in  claim 15 , comprising the steps of: 
 (a) preparing RNA samples from patients;    (b) separating the prepared RNA samples according to their size;    (c) using the DNA of  claim 4  as a probe, hybridizing it to the separated RNAs; and    (d) detecting the hybridized RNA and comparing the results with that of a normal, healthy person.    
     
     
         18 . The method for the diagnosis of Rothmund-Thomson syndrome in  claim 15 , comprising the steps of: 
 (a) preparing DNA samples from patients;    (b) amplifying the prepared DNA samples using the DNA of  claim 4  as a primer;    (c) dissociating the amplified DNA into single-stranded DNA;    (d) fractionating the dissociated single-stranded DNA on a non-denaturing gel; and    (e) comparing the mobility of the fractionated single-stranded DNA on the gel with that of a healthy normal person.    
     
     
         19 . The method for the diagnosis of Rothmund-Thomson syndrome in  claim 15 , comprising the steps of: 
 (a) preparing DNA samples from patients;    (b) amplifying the prepared DNA samples using oligonucleotides comprising a base that forms a base pair with the mutated base specific to Rothmund-Thomson syndrome in the DNA encoding RecQ4 helicase, or the expression regulatory region thereof, as at least one of the primers; and    (c) detecting the amplified DNA fragment.    
     
     
         20 . The method for the diagnosis of Rothmund-Thomson syndrome in  claim 15 , comprising the steps of: 
 (a) preparing DNA samples from patients;    (b) amplifying the prepared DNA samples using a pair of DNA of  claim 4  which is prepared so as to flank the mutated base specific to Rothmund-Thomson syndrome as the primer;    (c) hybridizing to the amplified product a pair of oligonucleotides selected from the group of: 
 (i) an oligonucleotide synthesized such that the base forming a base pair with the mutated base in the amplified product corresponds to the 3′-terminus, and an oligonucleotide synthesized such that the neighboring (on the 3′ side) base to said 3′-terminus corresponds to the 5′-terminus;  
 (ii) an oligonucleotide synthesized such that the base forming a base pair with the base of a normal healthy person which corresponds to the mutated base in the amplified product corresponds to the 3′-terminus, and an oligonucleotide synthesized such that the neighboring (on the 3′ side) base to said 3′-terminus corresponds to the 5′-terminus;  
 (iii) an oligonucleotide synthesized such that the base forming a base pair with the mutated base in the amplification product corresponds to the 5′-terminus, and an oligonucleotide synthesized such that the neighboring (on the 5′ site) base to said 5′-terminus corresponds to the 3′-terminus; and  
 (iv) an oligonucleotide synthesized such that the base forming a base pair with the base of a normal healthy person which corresponds to the mutated base in the amplified product corresponds to the 5′-terminus, and an oligonucleotide synthesized such that the neighboring (on the 5′ site) base to said 5′-terminus corresponds to the 3′-terminus;  
   (d) ligating the oligonucleotides; and    (e) detecting the ligated oligonucleotides.