Supplementary Material for: Ring Chromosome 17 Not Involving the Miller-Dieker Region: A Case with Drug-Resistant Epilepsy

Chromosomal abnormalities are often identified in people with
neurodevelopmental disorders including intellectual disability, autism,
and epilepsy. Ring chromosomes, which usually involve gene copy number
loss, are formed by fusion of subtelomeric or telomeric chromosomal
regions. Some ring chromosomes, including ring 14, 17, and 20, are
strongly associated with seizure disorders. We report an individual with
a ring chromosome 17, r(17)(p13.3q25.3), with a terminal 17q25.3
deletion and no short arm copy number loss, and with a phenotype
characterized by intellectual disability and drug-resistant epilepsy,
including a propensity for nonconvulsive status epilepticus.