Droplet digital PCR was used in concert with classic genotyping techniques (SNaPshot assays and pyrosequencing) to detect and characterize the tissue mosaicism of a somatic mutation (LIS1 c.190A>T; p.K64X) in a patient with posterior bilateral SBH and refractory epilepsy.
Patients with LIS1-associated classic lissencephaly typically present with severe psychomotor retardation and drug-resistant epilepsy within the first year.
Using microarray-based comparative genomic hybridization, 3 patients with epilepsy were revealed to have genomic copy number aberrations at 17p13.3: a partial LIS1 deletion in a patient with isolated lissencephaly and epilepsy, a triplication of LIS1 in a patient with symptomatic West syndrome, and a terminal deletion of 17p including YWHAE and CRK but not LIS1 in a patient with intractable epilepsy associated with distinctive facial features and growth retardation.