[A genomic study of adult-onset idiopathic hypoparathyroidism in Chinese by targeted next-generation sequencing].

OBJECTIVE: Several genes have been recognized to be associated with non-surgical hypoparathyroidism. Data about gene mutations in adult-onset hypoparathyroidism patients is lacking. This study was designed to screen gene mutation in adult-onset hypoparathyroidism in Chinese through the targeted next-generation sequencing (NGS). METHODS: We recruited 17 patients with adult-onset hypoparathyroidism who were regularly followed or newly diagnosed at our centre during the past one year. Nine of them developed hypercalciuria during the treatment with calcium and vitamin D. Eight of them were newly diagnosed with no treatment. Targeted NGS was performed to screen 11 related genes, including AIRE, AP2S1, CASR, CLDN16, FAM111A, GATA3, GCM2, PTH, TBCE, TBX1 and TRPM6. RESULTS: A novel homozygosis mutation of GCMB gene[c.130G>A (p.G44S)]was identified which was predicted to be deleterious by PolyPhen2. The patient was a 36-year-old woman who suffered from paroxysmal carpopedal spasms for ten years. Before treatment, the serum calcium and phosphorus was 1.48 mmol/L and 2.29 mmol/L, respectively.Parathyroid hormonel (PTH) concentration was lower than 3.0 ng/L. Intracranial calcification and cataract were also identified. She developed hypercalciuria during treatment with calcium and vitamin D. She had no physical deformity or family history of hypoparathyroidism. CONCLUSIONS: In this study, the genetic defect was only identified in 1 patient (5.9%). In adult-onset hypoparathyroidism without other diagnostic clues, the gene mutation screening as the first choice to clarify the etiology was not recommended.

Early Hypoparathyroidism Reversibility with Treatment of Riedel's Thyroiditis.

BACKGROUND: Riedel's thyroiditis (RT) is a rare, fibroinflammatory condition which induces gradual thyroid gland destruction and adjacent soft-tissue fibrous infiltration. About one- seventh of RT cases are associated with hypoparathyroidism, necessitating long-term therapy for symptomatic hypocalcemia. The reversibility of the parathyroid hormone deficit has not been fully described. PATIENT FINDINGS: A 40-year-old woman with no prior history of thyroid disease presented with a six month history of progressive thyroid enlargement complicated by worsening dysphagia and positional dyspnea. Her past medical history was remarkable only for retroperitoneal fibrosis. Physical examination revealed a large, hard, non-mobile goiter. Thyroid indices while maintained on levothyroxine were normal, but marked asymptomatic hypocalcemia with an inappropriately normal parathyroid hormone level was noted. Thyroid imaging and fine needle aspiration were consistent with RT. Isthmectomy and subsequent serial corticosteroid and tamoxifen treatment led to rapid symptom improvement. Serum calcium and parathyroid hormone levels returned to the reference range within three months. SUMMARY: We describe a case of RT in which hypoparathyroidism resolved after treatment targeted the mechanical compression and the fibroinflammatory milieu of the patient's thyroidal disease. CONCLUSIONS: RT can be associated with hypoparathyroidism that is clinically silent at presentation. Mechanical decompression of the goiter and immunomodulatory therapy can reverse the fibrosclerotic process and lead to rapid recovery of parathyroid gland function, as in this patient. However, in most cases hypoparathyroidism is persistent and requires continued treatment to prevent symptomatic hypocalcemia.

Evaluation of the autoimmune regulator (AIRE) gene mutations in a cohort of Italian patients with autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) and in their relatives.

OBJECTIVE: Autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) is a rare syndrome characterized by chronic candidiasis, chronic hypoparathyroidism and Addison's disease. APECED has been associated with mutations in autoimmune regulator (AIRE) gene. Our aim is to perform a genetic analysis of the AIRE gene in Italian APECED patients and in their relatives. Design AIRE mutations were determined by DNA sequencing in all subjects. Patients were tested for clinical autoimmune or non-autoimmune diseases, or for organ and non-organ specific autoantibodies. PATIENTS: A total of 24 Italian patients with APECED (15 from the Venetian region, 2 from Southern-Tyrol, 4 from Apulia, 3 from Sicily), 25 relatives and 116 controls were studied. RESULTS: Ten out of the 15 Venetian patients (66%) were homozygous for R257X or compound heterozygous with 1094-1106del13. One patient was homozygous for 1094-1106del13 and another for R139X. A novel mutation (1032-1033delGT) in combination with 1094-1106del13 was identified in one patient. No mutations were found in two cases. Two patients from Southern Tyrol were homozygous for R257X and for 1094-1106del13bp. All patients from Apulia were homozygous or heterozygous for W78R combined with Q358X. The patients from Sicily were homozygous for R203X or compound heterozygous with R257X. The analysis of the genotype-phenotype revealed that patients carrying 1094-1106del13 at the onset of Addison's disease were significantly older than those carrying other mutations. The genetic study of 25 relatives identified 20 heterozygous subjects. They suffered from various autoimmune and non-autoimmune diseases but no major disease of APECED was found. CONCLUSION: These data demonstrate the great genetic heterogeneity for the AIRE mutations in Italian APECED patients, and that the heterozygosity for AIRE mutations do not produce APECED.

Spontaneous hypoparathyroidism: clinical, biochemical and radiological features.

The clinical, biochemical and radiological features of spontaneously occurring hypoparathyroidism in 13 patients (mean age 9 years, range 4 months to 20 years) are highlighted. Nine patients presented with a history of generalised seizures and 2 were in acute hypocalcemic crisis at the time of admission. Ocular involvement (corneal opacities, cataract) was present in 3 patients and vitiligo in 1 patient. The serum calcium level was low (mean 5.46 mg/dl, range 5.0-7.2) and serum phosphorus level was high (mean 8.49 mg/dl, range 6-14 mg/dl) in all the patients. Six patients had elevated serum alkaline phosphatase (greater than 20 KAU). Radiological examination revealed osteopenia in 3 patients. Nine patients underwent a head CT scan; 5 had evidence of basal ganglia calcification. The findings of elevated serum alkaline phosphatase and osteopenia are at variance with existing literature and may possibly reflect pre-existing vitamin D deficiency.

Idiopathic hypoparathyroidism in black South Africans.

The spectrum of idiopathic hypoparathyroidism in black South Africans is described. Twelve patients were seen over a seven-year period. Major presenting features were tetany in 11, epilepsy in four, congestive cardiac failure in three, cataracts in four, neuropsychiatric disease in two, and basal ganglia calcification in four. Hypocalcaemia and hyperphosphataemia were apparent in all subjects at presentation. Parathyroid hormone levels were absent or inappropriately low in all. Important features highlighted were the long duration of symptoms before diagnosis, the suppression of tetany by treatment with diphenylhydantoin, the association of idiopathic hypoparathyroidism and epilepsy in adults, and the occurrence of reversible cardiac muscle dysfunction.