NFIX and syndrome caused by partial chromosomal deletion: However, with contiguous gene deletion of 300 kilobases to 3 megabases at the 19p13.13 locus that includes NFIX and CACNA1A, also known as the 19p13.13 microdeletion syndrome (OMIM 613638), seizures occur frequently; the deletion of NFIX results in overgrowth and the loss of the voltage-gated calcium channel CACNA1A causes seizures.