Intracardiac calcifications in a case of pseudohypoparathyroidism type Ia (PHP-Ia)

Case report: Metastatic cardiac calcifications in a patient with a history of rickets

Background

Metastatic cardiac calcifications are often seen in patients with renal failure and dialysis associated with vascular calcification and calcifications in other organs. There is little to no evidence of metastatic cardiac calcification in patients with a history of rickets.

Case summary

A 40-year-old patient with a history of rickets treated in infancy and no personal history of cardiovascular or renal disease came for a periodical examination. Transthoracic echocardiogram showed an important calcification in the mitral annulus and the mitro-aortic junction. Computed tomography (CT) showed marked calcification affecting the heart fibrous skeleton. Coronary arteries were not affected.

Discussion

Distribution of heart calcification seen both with echocardiography and CT is important to report so they can be identified as dystrophic or metastatic. These two have different aetiologies so the description may help identify the possible cause.

Intraarticular heterotopic ossification as the initial manifestation in a child with pseudohypoparathyroidism 1a

The authors describe a 6 year old girl who initially presented with limping due to intraarticular ossification of left knee joint but later developed carpopedal spasms. She had Albright's hereditary osteodystrophy phenotype with hypocalcemia and hyperphosphatemia with elevated parathyroid hormone. She was diagnosed to have pseudohypoparathyroidism 1a (PHP1a) with heterotopic intraarticular ossification. This case emphasizes the need for evaluation of PHP in patients with intraarticular ossification to facilitate early diagnosis of PHP.

Pseudohypoparathyroidism type 1a and insulin resistance in a child

Background. A 5-year-old white girl with a history of hypothyroidism in infancy presented to the endocrinology clinic of a tertiary hospital. Her physical examination noted a stocky physique, broad chest, short neck and short digits. Two years later, skin examination revealed subcutaneous nodules and acanthosis nigricans.Investigations. Measurement of levels of serum phosphate, parathyroid hormone, ionized calcium and insulin; measurement of peak growth hormone by the arginine-levodopa stimulation test; calculation of homeostasis model assessment of insulin resistance; assessment of bone age; DNA analysis of the GNAS gene.Diagnosis. Pseudohypoparathyroidism type 1a in a patient with Albright hereditary osteodystrophy, characterized by hypocalcemia, hypothyroidism, growth-hormone deficiency and insulin resistance.Management. The child continued to take levothyroxine 25 microg once daily, and at 5 years of age she was started on 40 mg/kg elemental calcium as calcium carbonate daily, and calcitriol (active vitamin D) 0.25 microg twice daily. Lifestyle modifications were also recommended for weight control. At 6 years and 4 months of age, treatment with growth hormone was initiated at a dose of 0.3 mg/kg weekly.

Ectopic cardiac calcification associated with hyperparathyroidism in a boy with hypophosphatemic rickets

An adolescent with hypophosphatemic rickets developed cardiac calcifications in the absence of hypercalcemia or elevation of the phosphocalcic product (the product of the total serum calcium and phosphorus concentrations). Cardiac calcifications led to aortic and mitral valve dysfunction, myocardial calcification, and arrhythmia. Hyperparathyroidism probably played a significant role in the development of this complication, which emphasizes the necessity for intermittent assessment of parathyroid status in individuals receiving medical therapy for hypophosphatemic rickets.

Albright's hereditary osteodystrophy

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Endocrine and molecular biological studies in a German family with Albright hereditary osteodystrophy

We examined a German family with five members affected by Albright hereditary osteodystrophy (AHO). The only patient with pseudohypoparathyroidism type Ia (PHP-Ia) presented clinically with latent tetany, mental retardation, round face, short stature, brachymetacarpia and calcifications of subcutaneous tissue, heart and brain, whereas all other four members with pseudopseudohypoparathyroidism (pseudo-PHP) showed only subcutaneous calcifications and brachymetaphalangia. The PHP-Ia patient exhibited hypocalcaemia, hyperphosphataemia, elevated immunoreactive parathyroid hormone (PTH), and a blunted response of cyclic adenosine monophosphate (cAMP) in plasma and urine to synthetic 1-38 hPTH. In addition, latent primary hypothyroidism was found. In contrast, all tested healthy family members as well as the patients with pseudo-PHP exhibited normal calcium metabolism including cAMP response to exogenous PTH. In Northern blot experiments all patients with AHO, regardless whether affected by PHP-Ia or pseudo-PHP, revealed significantly reduced mRNA levels coding for the alpha subunit of the G protein that stimulates adenylyl cyclase (Gs alpha), when compared with healthy family members. In contrast, there was no significant difference between healthy and affected subjects with regard to the levels of the mRNA coding for the alpha subunit of Gi alpha-2, the main inhibitory G protein of adenylyl cyclase. The results indicate that reduced expression of Gs alpha is a useful genetic marker in some families with AHO, regardless whether patients are affected by PHP-Ia or by pseudo-PHP.