Causes include the following: * Losses from translocation * Chromosomal crossovers within a chromosomal inversion * Unequal crossing over * Breaking without rejoining For synapsis to occur between a chromosome with a large intercalary deficiency and a normal complete homolog, the unpaired region of the normal homolog must loop out of the linear structure into a<unk> or compensation loop.
Deletion 
Flagging 
Mutation
Efference copy
Aplasia
Honeycombing
Exon shuffling
ConFusion