Severe epilepsy, retardation, and dysmorphic features with a 2q deletion including SCN1A and SCN2A

Case report.

The patient was the only child of healthy, unrelated parents. During gestation a cleft lip and palate were detected. The fetal karyotype was considered normal. Vaginal delivery was at 39 weeks. Birth weight was 2,750 g and length was 49 cm. Additional dysmorphic features included microcephaly, downslanting and small palpebral fissures, abnormal external ears with thick helix, single palmar creases bilaterally, and partial syndactyly between the second and third toes. Neurologic examination was normal. Cardiologic examination revealed a small interventricular communication. A new karyotype detected a deletion at chromosome 2q24 (data not shown).

She first had epileptic seizures at age 2 months, which were predominantly tonic and asymmetric, involved the left or right limb and face, and were accompanied by severe apnea and cyanosis. Seizures were brief and responded temporarily to phenobarbital. She subsequently had multiple seizures and status epilepticus lasting 2 to 3 days and occurring in clusters. Seizure-free intervals lasted 4 days to 3 weeks. Within a few months the seizure pattern became clonic, multifocal, and migratory. Neurologic and developmental assessment became abnormal at age 2 months. Visual behavior was abnormal with no consistent fixation or tracking. Response to sounds was questionable, and suction was poor. She had poor …