An isolated nucleic acid molecule comprising the nucleotide sequence set forth in SEQ ID NO: 1.
1. A method of detecting the presence of a mutation in the human ARX gene comprising: isolating a nucleotide sequence comprising at least an exon of the human ARX gene from a test sample; performing an assay to compare said nucleotide sequence with the nucleotide sequence of a wild-type human ARX gene, and identifying a difference between the nucleotide sequences that is an insertion of trinucleotide repeats coding for additional alanine residues within a polyalanine tract, wherein identification of said difference between the nucleotide sequences indicates the detection of the presence of a mutation in the human ARX gene.
2. The method of claim 1 , wherein the wild-type ARX gene comprises SEQ ID NO:1.
3. The method of claim 1 , wherein the test sample comprises SEQ ID NO:4.
4. A method for detecting the presence of X-linked infantile spasms in a human subject comprising: isolating a nucleotide sequence comprising at least an exon of the human ARX gene from a sample obtained from the subject; performing an assay to compare said nucleotide sequence with a nucleotide sequence that encodes wild-type ARX; and identifying a difference between the nucleotide sequences that is an insertion of trinucleotide repeats coding for additional alanine residues within a polyalanine tract, wherein identification of said difference between the nucleotide sequences is indicative of the detection of the presence of X-linked infantile spasms.
5. The method of claim 4 , wherein the assay is selected from the group consisting of: SSCP, PCR, DGGE, DHPLC, microarray and Southern blot-based tests.
6. The method of claim 5 , wherein a sequence comparison is made by a hybridization assay.
7. A method for predicting the likelihood that a human individual will have X-linked infantile spasms, comprising isolating a nucleotide sequence comprising at least an exon of the human ARX gene from a nucleic acid sample obtained from the individual, performing an assay to compare said nucleotide sequence with a nucleotide sequence that encodes wild-type ARX; and identifying a difference between the nucleotide sequences that is an insertion of trinucleotide repeats coding for additional alanine residues within a polyalanine tract of the ARX gene, wherein said difference, is indicative of the likelihood that the individual from whom the sample was obtained will have X-linked infantile spasms.
8. The method of claim 7 , wherein the nucleic acid sample comprises an mRNA sample.
9. The method of claim 8 , wherein the nucleotide sequence is analyzed using specific hybridization probes.
10. The method of claim 7 , wherein the nucleotide sequence is analyzed using an assay selected from the group consisting of: SSCP, PCR, DGGE, DHPLC, microarray and Southern blot-based tests.
11. The method of claim 1 , wherein the mutation is an insertion of (GCG) 7 trinucleotide repeats within the first polyalanine tract.