Seizures as the first manifestation of chromosome 2q24.2-q24.3 in a two and a half years old girl: A case report

Abstract

Background: Mutations and/or duplications in the chromosome 2q24.3 region are known to be responsible for various epilepsy phenotypes. However, microdeletion in childhood epilepsy is rarely reported. Case presentation: A two-and-a-half-year-old girl with no history of hypocalcemia or seizures developed new symptoms of generalized tonic-clonic epilepsy. The clinical manifestations were growth retardation, prominent forehead, closed anterior fontanelle, and poor muscle tension. Peripheral blood, echocardiography, abdominal ultrasound, and electroencephalogram (EEG) examinations were all normal. No karyotype abnormality was found in the patient, but a single nucleotide polymorphism (SNP) array test detected that a 3.5 Mb single-copy microdeletion had occurred in the q24.2-q24.3 region on chromosome 2. Fluorescence in situ hybridization (FISH) tests revealed that the 2q24 fragment was inserted into the q11.2 region of the patient's chromosome 15, as well as that of her sister. In both cases, the patient's mother is the source carrier of the chromosome 15 insertion. Conclusions: The deletion of the sodium channel gene cluster (SCN1A, SCN2A, and SCN3A), but not SCN1A haploinsufficiency ​alone, may contribute to complex infant epilepsy syndromes. However, the pathogenic mechanism still needs to be studied further.

Keywords

• Seizure
• Chromosome 2q22.2-q24.3
• Microdeletion
• Maternal origin