Department of Endocrinology, University of Sydney Nepean Clinical School, Penrith, NSW, Australia.
Endocr Pract. 2011 Sep-Oct;17(5):e123-5. doi: 10.4158/EP11102.CR.
To describe the first case of established chromosome 22q11 deletion syndrome with late onset presentation of hypocalcemia secondary to hypoparathyroidism.
We present the history, clinical and laboratory investigations, and management of a 17-year-old adolescent boy who presented with 3 separate seizures secondary to hypocalcemia. This patient had an established diagnosis of chromosome 22q11 deletion syndrome at the time of the seizure presentations, but had previously normal calcium levels.
Hypocalcemia was noted during each seizure, with corrected calcium levels ranging from 6.64 to 7.76 mg/dL (reference range, 8.52 to 10.52 mg/dL). The hypocalcemia was secondary to hypoparathyroidism, with parathyroid hormone levels < 2.75 pg/mL (reference range, 22.9 to 68.75 pg/mL). He was treated with calcitriol, 0.5 μg daily, and calcium carbonate, 2,400 mg daily, leading to normalization of serum calcium and resolution of seizures.
Chromosome 22q11 deletion syndrome is a relatively common genetic disorder with a wide variety of phenotypic manifestations including cardiac abnormalities, abnormal facies, thymic dysfunction, cleft palate, and hypocalcemia. This case shows that medical practitioners should be aware that hypocalcemia can present after an established diagnosis, which has implications for the management of this disorder.
描述首例染色体 22q11 缺失综合征病例，该病例表现为甲状旁腺功能减退引起的低钙血症，且发病较晚。
我们报告了一名 17 岁青少年的病史、临床和实验室检查以及治疗情况，该患者因低钙血症发作了 3 次癫痫。该患者在癫痫发作时被确诊为染色体 22q11 缺失综合征，但此前血钙水平正常。
每次癫痫发作时均出现低钙血症，校正后的血钙水平为 6.64-7.76mg/dL（参考范围为 8.52-10.52mg/dL）。低钙血症继发于甲状旁腺功能减退，甲状旁腺激素水平<2.75pg/mL（参考范围为 22.9-68.75pg/mL）。他接受了骨化三醇治疗，每天 0.5μg，碳酸钙治疗，每天 2400mg，导致血清钙正常化并缓解了癫痫发作。
染色体 22q11 缺失综合征是一种较为常见的遗传性疾病，其表型表现多种多样，包括心脏异常、异常面容、胸腺功能障碍、腭裂和低钙血症。本病例表明，临床医生应该意识到，在确诊后可能会出现低钙血症，这对这种疾病的管理有影响。
