Abstracts

Rationale: The deletion of the distal short arm of chromosome 12 are rare structural aberrations. The reported clinical manifestations in patients with 12p13.3 deletion were developmental delay/intellectual disability, facial dysmophisms, and psychiatric problems. Hear we report on a family with 3.2 Mb 12p13.33-p13.32 microdeletions, whose main phenotype is characterized by ID, epilepsy, and schizophrenia.  Methods: G-banded chromosome analysis was performed on peripheral blood lymphocytes according to standard techniques. A genomic microarray was performed using the SurePrint G3 Human CGH+SNP Microarray 4x180K kit (Agilent Technologies, Inc., Santa Clara, CA, USA), and no abnormalities were shown.  Results: The twelve-year-girl came to our hospital for status epilepticus and intellectual disability. She was born at 40 weeks of gestation, after spontaneous delivery, to non-consanguineous 28 year-old mother and 30-year-old father. The pregnancy was uneventful. Her birth weight was 3,420g (50th percentiles), length 52cm (75th percentile), head circumference 35cm (50th percentiles). Her elder sister was healthy and appeared normal and her mother, but her mother had mild intellectual disability and schizophrenia Under phenobarbital and levetiracetam, epilepsy has been controlled. Brain magnetic resonance imaging (MRI) showed no obvious abnormalities with a normal myelination pattern. Electroencephalography revealed sharp-and-slow waves on left central regions. Her intellectual quotient (IQ) was estimated at 60, indicating moderate intellectual disability on the Wechsler Intelligence Scale for Children Revised. Array CGH identified a 3.2 Mb terminal deletion at 12p13.33, which encompasses 27 genes (IQSEC3, SLC6A12, SLC6A13, KDM5A, CCDC77, B4GALNT3, NINJ2, WNK1, HSN2, RAD52, ERC1, LOC100292680, FBXL14, WNT5B, ADIPOR2, CACNA2D4, LRTM2, DCP1B, CACNA1C, FKBP4, ITFG2, NRIP2, FOXM1, C12orf32, TULP3, TEAD4, and TSPAN9). The deletion was inherited from the mother.  Conclusions: The 12p13 deletion should be considered in any child with a differential diagnosis of epilepsy, ID and schizopherenia. Further study focusing on careful phenotyping across the lifespan to understand the potential contributions of genetic modifiers and environmental influence on the expressivity of 12p13 deletion and associated characteristics will be invaluable to further determine the impact that 12p13 deletion have on human psychopathology.  Funding: No funding