Congenital absence of parathyroid

Congenital Absence of the Parathyroid Glands

The congenital absence of the parathyroid glands is a rare condition that affects the endocrine system, specifically the parathyroid glands. These glands are crucial for maintaining balanced levels of calcium and phosphorus in the blood. Their absence leads to a condition known as hypoparathyroidism, which is characterized by low levels of calcium in the blood (hypocalcemia) and high levels of serum phosphorus.

Causes

The congenital absence of the parathyroid glands can occur as an isolated anomaly or as part of a genetic syndrome. One of the most common syndromes associated with this condition is DiGeorge Syndrome (22q11.2 deletion syndrome), which affects several body systems and can lead to heart defects, immune deficiencies, and developmental delays. The exact cause of the congenital absence of the parathyroid glands when it occurs in isolation is not well understood but is believed to involve genetic mutations affecting the development of the third and fourth pharyngeal pouches during embryogenesis.

Symptoms

The primary symptom of the congenital absence of the parathyroid glands is hypocalcemia, which can lead to neuromuscular irritability, including tetany (involuntary muscle contractions), seizures, and, in severe cases, heart failure. Children and infants may exhibit feeding difficulties, poor weight gain, and developmental delays. The condition can also cause dental abnormalities and cataracts.

Diagnosis

Diagnosis of the congenital absence of the parathyroid glands involves measuring serum calcium and phosphorus levels, as well as parathyroid hormone (PTH) levels. Low calcium, high phosphorus, and undetectably low PTH levels are indicative of hypoparathyroidism due to the absence of the parathyroid glands. Imaging studies, such as ultrasound or MRI, may be used to confirm the physical absence of the glands. Genetic testing can also be helpful, especially if a syndrome like DiGeorge Syndrome is suspected.

Treatment

Treatment focuses on managing hypocalcemia and includes oral calcium supplements and active forms of vitamin D (e.g., calcitriol) to help increase calcium absorption from the gut. Regular monitoring of calcium and phosphorus levels is necessary to adjust treatment and prevent complications. In cases associated with genetic syndromes, additional treatments may be required to address other symptoms or anomalies.

Prognosis

With appropriate treatment, individuals with congenital absence of the parathyroid glands can lead relatively normal lives. However, they require lifelong monitoring and treatment to manage hypocalcemia and prevent complications.

See Also

• Hypoparathyroidism
• DiGeorge Syndrome
• Endocrine System
• Calcium Metabolism