A 12-year-old boy presented with a new onset generalized tonic-clonic seizure. He is the first child of a phenotypically normal mother. The patient was born at term after an uneventful pregnancy by an uncomplicated caesarean section with low birth weight of 2,900g (10–25th percentile). At 8 months the child underwent surgical repair of a cleft palate and at age 2 years had two episodes of febrile convulsion. He had a learning disability in his school-aged years. On family history, his father had a prominent forehead, small down-turned mouth, micrognathia, and nasal voice (). He had not undergone any prior specific evaluation, but seemed to have normal intelligence without any neuropsychiatric symptoms including a seizure history.\nPhysical examination revealed prominent forehead, small down-turned mouth, micrognathia (), and repaired cleft palate with not well formed uvula (). His height was 146 cm (25–50th percentile) and weight was 38.5 kg (25–50th percentile). Chvostek’s and Trousseau’s signs were negative. He had mild mental retardation with an intelligence quotient (IQ) of 68 on the Korean version of Wechsler Intelligence Scale for Children (K-WISC).\nThe electrocardiogram (ECG) was abnormal due to a prolonged corrected QT interval and the chest radiograph failed to show a thymus shadowing. Computed tomography (CT) of the heart revealed right aortic arch (), and CT of the brain showed multiple calcifications in the bilateral basal ganglia and both frontal white matters (). The electroencephalogram (EEG) revealed generalized intermittent slow waves without any epileptiform discharges.\nLaboratory tests showed hypocalcemia (calcium 6.5 mg/dL, ionized calcium 2.8 mg/dL), hyperphosphatemia (9.1 mg/dL) and normal level of magnesium (1.8 mg/dL). Parathyroid hormone (PTH) was decreased to 4.76 pg/mL (reference range 15–65 pg/mL) and 25-vitamin D3 was decreased to 13.6 ng/mL (reference range 30–60 ng/mL). Peripheral blood count, hepatic, renal and thyroid function tests were all normal except thrombocytopenia (144,000/μL). Immunological studies showed normal levels of Immunoglobulins but T cell subpopulation analysis was abnormal. T lymphocyte was decreased to 42.8 %/μL (reference range 52–78%/μL), CD4/CD8 T cell ratio was decreased to 0.79 (reference range 0.8–3.0).\nFluorescent in situ hybridization (FISH) analysis was performed using peripheral blood and chromosomal study was carried out using DiGeorge/VCFS TUPLE1 region probe (22q11.2) with an ARSA control probe (22q13) which confirmed a 22q11.2 deletion. His father revealed the same chromosomal abnormality, which suggests paternal inheritance in this case.\nThe patient was treated with calcium citrate and calcitriol. He remained asymptomatic with normalization of his serum calcium level with medications.
A 12-year-old boy presented with a new onset generalized tonic-clonic seizure. He is the second child of phenotypically normal parents, born at term after an uneventful pregnancy by an uncomplicated caesarean section with low birth weight of 2,800 g (10–25th percentile). At age 1 year, the child underwent surgical repair of patent ductus arteriosus. At age 6 and 7 years, he had two episodes of febrile convulsion. He had a learning difficulty in his school-aged years. He did not have any family history of similar clinical conditions.\nPhysical examination was abnormal due to a prominent forehead, small down-turned mouth, micrognathia and bifida uvula. His height was 155.8 cm (90–97th percentile) and weight was 59.7 kg (75–90th percentile). Chvostek’s and Trousseau’s signs were negative. On neurological evaluation, his verbal fluency was decreased.\nThe ECG showed a prolonged corrected QT interval and chest X-ray failed to show a thymus shadowing. The brain CT revealed calcification located in the left basal ganglia (). The EEG was abnormal due to generalized intermittent slow waves without any epileptiform discharges.\nLaboratory tests showed hypocalcemia (calcium 6.9 mg/dL, ionized calcium 3.8 mg/dL), hyperphosphatemia (8.3 mg/dL) and normal level of magnesium (1.7 mg/dL). PTH was normal with 21.91 pg/mL (reference range 15–65 pg/mL) and 25-vitamin D3 was decreased to 22.9 ng/mL (reference range 30–60 ng/mL). Peripheral blood count, hepatic and renal function tests were all within normal range except mild thrombocytopenia (130,000/μL). A 22q11.2 deletion was confirmed by a FISH analysis.\nThe patient was treated with calcium citrate and calcitriol. He remained asymptomatic with normal serum calcium level with medications.