Familial isolated hyperparathyroidism (SIHP) is a rare inherited disorder characterized by excessive production of parathyroid hormone (PTH), leading to hypercalcemia and a number of associated metabolic disturbances. The disease is usually caused by genetic mutations and manifests itself in various forms, including multiple endocrine neoplasia. The most pronounced clinical manifestations are associated with bone damage, kidney dysfunction, and frequent episodes of elevated calcium in the blood. Clinical features of the disease can vary from asymptomatic course to serious complications, including osteoporosis, kidney stones, and tissue dysplasia.
History of the disease and interesting historical facts
Familial isolated hyperparathyroidism was first described in the medical literature in the mid-20th century. Interestingly, the definition and diagnosis of this condition became possible due to an improved understanding of the endocrine system and its pathology. One of the earliest cases described in the literature was in the 1950s, when observation of the family history made it possible to identify the genetic nature of the disease. Further research helped establish a link between SIH and certain mutations in the genes that control parathyroid function.
Epidemiology
According to epidemiological data, the prevalence of familial isolated hyperparathyroidism varies from 1 to 4 cases per 100,000 people in different populations. It is known that the disease is more common in people of European descent. It is important to emphasize that in many cases hereditary factors are at play, which requires attention to the family history of diseases during diagnosis. Long-term studies show that the incidence of SIHP may be underestimated, since many cases remain unrecognized or do not have clear clinical manifestations.
Genetic predisposition to this disease
Familial isolated hyperparathyroidism is caused in most cases by mutations in genes responsible for PTH production. The most studied genes involved in pathogenesis include MEN1 (multiple endocrine neoplasia type 1 gene) and CASR (calcium receptor gene). In addition, similar mutations can be observed in the CDKN1B and RET genes. Changes in these genes can lead to dysregulation of parathyroid hormone production and secretion, causing hyperparathyroidism. Genetic studies play a key role in diagnosis and determination of appropriate treatment methods, as well as in predicting relapses of the disease.
Risk factors for the development of this disease
The main risk factors that contribute to the development of familial isolated hyperparathyroidism include:
- Heredity: Having relatives with the disease increases the risk of its occurrence.
- Age: the disease is most often diagnosed in middle-aged people.
- Gender: Studies show a slightly higher prevalence in women.
- Certain mutations in genes associated with the regulation of calcium metabolism may also serve as predictors of disease development.
Diagnosis of this disease
Diagnosis of familial isolated hyperparathyroidism is based on a combination of clinical manifestations, laboratory tests, and imaging studies. The main symptoms include:
- Fatigue and weakness;
- Bone and joint pain;
- Renal dysfunction, including stone formation;
- Difficulty concentrating and cognitive impairment.
Laboratory tests needed for diagnosis include blood calcium and PTH levels. Radiological examinations can help identify osteoporosis and bone changes. Other diagnostics may include genetic testing to identify mutations. It is important to differentiate the diagnosis from other forms of hyperparathyroidism, including primary and secondary hyperparathyroidism, to avoid misinterpretation of symptoms.
Treatment
Treatment for familial isolated hyperparathyroidism may vary depending on the severity of symptoms and the level of hypercalcemia. Possible approaches include:
- General treatment involves prescribing a low-calcium diet and vitamin D to reduce blood calcium levels.
- Pharmacological treatment may include the use of bisphosphonates and other calcium-lowering medications.
- Surgical treatment is indicated in cases of severe hyperparathyroidism and includes removal of the parathyroid glands, which is the most effective method.
- Other treatments may include the use of special medications aimed at correcting metabolism and hormone levels.
List of medications used to treat this disease
The group of drugs used to treat hyperparathyroidism include:
- Bisphosphonates (eg, allendronate, risedronate);
- Selective estrogen receptor modulators;
- Decreased parathyroid hormone (eg, prazosin, dinoporod);
- Calcitonin;
- Calcium and vitamin D preparations.
Disease monitoring
Monitoring of the patient with familial isolated hyperparathyroidism includes regular examinations to control calcium and PTH levels. The prognosis of the disease largely depends on the time of treatment initiation and compliance with the doctor's recommendations. Possible complications include osteoporosis, kidney stones, and cardiovascular disorders. Timely diagnosis and treatment can significantly reduce the risk of complications and determine a positive course of the disease.
Age-related features of the disease
Familial isolated hyperparathyroidism may present differently depending on the age group. In children and adolescents, the disease may lead to growth retardation and osteoporosis. In adults, symptoms are more often associated with disorders of bone metabolism and kidney function. In older people, the risk of the previously listed complications, such as osteoporosis and its consequences (fractures), is high, which requires special attention in diagnosis and treatment.
Questions and Answers
- What are the main symptoms of familial isolated hyperparathyroidism? The main symptoms include fatigue, bone pain, frequent kidney stones and cognitive impairment.
- How is familial isolated hyperparathyroidism diagnosed? Diagnosis includes laboratory tests for calcium and PTH levels, as well as genetic testing.
- What treatment is recommended for patients with this condition? Treatment may include diet, medications to lower calcium levels, and surgery if needed.
- What is the prognosis with timely diagnosis and treatment? The prognosis is often considered favorable with timely diagnosis and adequate treatment.
- How important is genetic counseling for this disease? Genetic counseling can help with early diagnosis and risk assessment for family members.
Dr. Oleg Korzhikov recommends paying attention to your family history and, if you have suspicious symptoms, contacting specialists in a timely manner. An important aspect is regularly checking the level of calcium and PTH in the blood, as well as following all doctor's instructions. If you have already been diagnosed with SIHP, it is important to monitor your condition, paying attention to nutrition and lifestyle issues, which can significantly improve your quality of life and reduce the risk of complications.
