Departamento de Endocrinologia e Nutrição, Centro Hospitalar de Vila Nova de Gaia/Espinho (CHVNG/E), Vila Nova de Gaia, Portugal,
Departamento de Endocrinologia e Nutrição, Centro Hospitalar de Vila Nova de Gaia/Espinho (CHVNG/E), Vila Nova de Gaia, Portugal.
Arch Endocrinol Metab. 2021 Nov 1;65(1):112-116. doi: 10.20945/2359-3997000000316. Epub 2020 Dec 15.
Pseudohypoparathyroidism comprehends an assorted group of genetically rare disorders that share end-organ resistance to parathyroid hormone. Genetic and epigenetic modifications on guanine nucleotide-binding protein alpha-stimulating gene locus are the most common underlying mechanisms associated with pseudohypoparathyroidism. Biochemical and molecular analysis stratify pseudohypoparathyroidism into types 1A, 1B, 1C, and 2. We describe an unusual case of sporadic pseudohypoparathyroidism type 1B. A 34-year-old Caucasian woman was admitted to the emergency department, with persistent asthenia, limb paresthesias, and tactile hyposensitivity. Her physical examination, previous personal and family histories were unsuspicious, except for mild, intermittent and self-limited complaints of paresthesia during her two pregnancies, but no detailed workup was done. No typical features of Albright hereditary osteodystrophy were observed. The initial laboratory investigation showed elevated parathyroid hormone level (311.2 pg/mL), hypocalcemia (albumin-corrected serum calcium 4.3 mg/dL), hypocalciuria, hyperphosphatemia, hypophosphaturia, and vitamin D deficiency. Combined calcium, vitamin D, and magnesium supplementation was commenced, with symptomatic and analytical improvement. Albeit resolution of vitamin D deficiency, the patient relapsed with mild and intermittent lower limb paresthesias. Pseudohypoparathyroidism was confirmed by molecular identification of the 3-kb STX16 deletion. The treatment was readjusted, and one year later, symptomatic remission was attained. Clinical and biochemical features, and their respective course, along with lack of distinctive features of Albright hereditary osteodystrophy pointed to pseudohypoparathyroidism type 1B. A careful follow-up is needed to avoid complications and recurrence. Once correction of hypocalcemia and hyperphosphatemia is achieved, with no reported complications and recurrence, a good prognosis is anticipated, comparable to the general population.
假性甲状旁腺功能减退症包括一组遗传罕见疾病，这些疾病具有甲状旁腺激素作用的终末器官抵抗。鸟嘌呤核苷酸结合蛋白α刺激基因座的遗传和表观遗传修饰是与假性甲状旁腺功能减退症相关的最常见潜在机制。生化和分子分析将假性甲状旁腺功能减退症分为 1A、1B、1C 和 2 型。我们描述了一例罕见的散发性假性甲状旁腺功能减退症 1B 型病例。一名 34 岁的白人女性因持续性乏力、四肢感觉异常和触觉感觉减退而被收入急诊部。她的体格检查、既往个人和家族史均无异常，仅在两次妊娠期间出现短暂性、间歇性和自限性感觉异常，但未进行详细检查。未观察到典型的 Albright 遗传性骨营养不良特征。初始实验室检查显示甲状旁腺激素水平升高（311.2 pg/mL）、低钙血症（白蛋白校正血清钙 4.3 mg/dL）、低钙尿症、高磷血症、低磷血症和维生素 D 缺乏。开始联合补充钙、维生素 D 和镁，症状和分析均有所改善。尽管维生素 D 缺乏得到纠正，但患者仍有轻度间歇性下肢感觉异常。通过分子鉴定发现 STX16 3kb 缺失，从而确诊为假性甲状旁腺功能减退症。调整治疗后，一年后，患者症状缓解。临床和生化特征及其各自的病程，以及缺乏 Albright 遗传性骨营养不良的特征性表现，均提示为假性甲状旁腺功能减退症 1B 型。需要进行仔细的随访，以避免并发症和复发。一旦实现低钙血症和高磷血症的纠正，且无报道的并发症和复发，预期预后良好，与一般人群相当。
