Hypoparathyroidism

The Adult Endocrinology Clinic provides diagnosis and follow-up for adult patients with an endocrine problem, that is, a condition affecting the secretion of a hormone (excessive or insufficient secretion) and/or the gland that secretes it. The department therefore manages conditions affecting the thyroid, parathyroid glands, adrenal glands, gonads (ovaries and testicles) and pituitary gland.

Since 2016, the Endocrinology Department of Erasme Hospital, together with the Queen Fabiola Children’s University Hospital (HUDERF) for the paediatric component, has been part of ENDO-ERN (European Reference Network for Rare Endocrine Conditions), the European Reference Network for rare endocrine diseases.

The mission of this network is to improve access to high-quality care for patients with rare endocrine disorders. It supports clinical research and contributes to the creation of registries listing patients monitored for rare conditions, in order to promote knowledge sharing and improve clinical practices. 

The management of rare endocrine diseases is multidisciplinary. Regular consultations are organised to discuss complex cases, involving numerous specialists within our institution, as well as through virtual consultations with recognised European experts via the ENDO-ERN network or during international multidisciplinary case-review meetings (France).

Some endocrine diseases begin at birth or during childhood and require lifelong treatment and follow-up. Transition consultations have been provided for many years in collaboration with our paediatric colleagues at HUDERF, to ensure the smoothest possible transition from paediatric to adult care.

Hypoparathyroidism and pseudohypoparathyroidism (recently referred to as IPPSD type 2, or “Inactivating PTH/PTHrP Signaling Disorder”) are rare diseases of the parathyroid glands. The parathyroid glands are four small glands located next to the thyroid gland that secrete parathyroid hormone (PTH), a hormone essential for regulating calcium and phosphorus levels in the body. These diseases cause a decrease in the level of calcium in the blood. This hypocalcaemia can cause a range of symptoms, depending on its severity and how quickly it develops: cramps, muscle stiffness, tingling in the extremities, unusual fatigue, irritability, attention and concentration problems, and seizures.

The disease may be present from birth or childhood, as part of a genetic syndrome, or may be acquired later in life, most often as a complication of thyroid surgery (thyroidectomy). Pseudohypoparathyroidism is a particular and very rare form of hypoparathyroidism, linked to a genetic mutation that makes the body resistant to the action of parathyroid hormone. There is no defect in PTH secretion, but the mutation impairs its action. The disease generally appears during childhood and is associated with resistance to other hormones, most often thyroid hormones, but sometimes also growth hormone or the hormones involved in puberty.

In most cases, the diagnosis is suspected on the basis of symptoms suggestive of hypocalcaemia (cramps, tingling, etc.) and confirmed by a blood test (calcium, phosphate, PTH levels, etc.). In the majority of cases, hypoparathyroidism in adults occurs after a thyroidectomy. In other cases, genetic testing may be necessary to rule out hereditary conditions and to guide the diagnosis and management. The aim of treatment is to maintain calcium and phosphate levels as close to normal and as stable as possible, in order to alleviate symptoms and prevent complications. Treatment generally combines calcium and active vitamin D supplementation, with individualised adjustment. New molecules that are very similar in structure to parathyroid hormone (= “PTH analogues”) are currently being evaluated in clinical studies and are already being used in some European countries for adult patients.

Management is multidisciplinary, involving endocrinologists, dietitians (advice on dietary calcium intake) and, depending on the situation, geneticists, nephrologists and psychologists. The aim is to provide patients with the best possible support in understanding their condition and treatment, and to sustainably improve their quality of life.

Adherence to treatment and regular medical follow-up are essential. It is important to respect the number of doses and the prescribed doses of the supplements, and to report any change in general condition to the healthcare team, such as unusual fatigue or persistent or recurrent symptoms of hypocalcaemia. A balanced diet also contributes to maintaining good mineral balance. In the event of unusual acute symptoms (discomfort, severe spasms, altered consciousness), it is recommended to go to the Emergency Department without delay. If in doubt, the medical team remains the best point of contact for adapting the care plan.

During adolescence, a gradual preparation for the transition to adult care is organised. This stage helps strengthen the young patient’s autonomy, ensure continuity of medical follow-up and transfer all the necessary information to the specialised adult service. The transition is planned in collaboration with the patient, their family, and the paediatric and adult teams.

Patients are treated by a licensed adult endocrinologist. Hormone assays and genetic tests are performed in a specialised laboratory. An on-call service is available 24 hours a day. Our centre is actively involved in improving knowledge and care for patients with rare endocrine diseases. A local registry has been established. A dedicated European ERN database for hypoparathyroidism will be set up shortly. The aim is to better understand the course of the disease, optimise follow-up practices, and compare management approaches between different specialised centres. The team undertakes continuous professional development, participates in congresses and seminars, initiates and collaborates on studies, and publishes in the field of parathyroid disorders. It also provides training and teaching for students and doctors in training.