Hypoparathyroidism Identified as Sign of DiGeorge Syndrome in Adult Man
Symptoms of hypoparathyroidism were among the first signs of DiGeorge syndrome (DGS) in a man in whom standard treatment successfully restored calcium levels before surgery to remove his thyroid, which showed evidence of cancer, according to a recent case report.
The report, “Newly Diagnosed Hypoparathyroidism as the Initial Presentation of DiGeorge Syndrome in a 26-Year-Old Man,” was recently published in the journal AACE Clinical Case Reports.
Low bodily amounts of the parathyroid hormone (PTH), an important regulator of blood calcium levels, cause hypoparathyroidism. This results in hypocalcemia, or low blood calcium levels, and high phosphorus levels, leading to hypoparathyroidism symptoms of muscle cramps, pain, and twitching, among others.
Hypoparathyroidism is a symptom of DiGeorge syndrome, a genetic disorder caused by a deletion of a part of chromosome 22. DGS is accompanied by a range of symptoms, including cardiac, neuropsychiatric, skeletal, endocrine, and thyroid abnormalities. Diagnosis is typically early in life, but some cases may only be identified later.
During a preoperative doctor’s appointment before thyroid gland removal due to the presence of a goiter, or thyroid enlargement, a 26-year-old African American male said he had leg cramps and breathing difficulties.
His medical history noted developmental delay, short stature, dental problems, a sideways spine curvature known as scoliosis, and a previous surgery to correct undescended testicles in infancy.
During a physical exam, a prominent forehead, bulbous nose, and abnormal folding of ear cartilage were observed. The man also had a displaced trachea, which occurs when the tube that carries air from the lungs is pushed to one side. He did not have any cardiac symptoms.
Lab tests showed signs of hypoparathyroidism, including diminished calcium levels at 6.1 milligrams per deciliter (mg/dL; normal range: 8.7–10.4 mg/dL) and vitamin D deficiency, with levels at 12.21 nanograms per mL (ng/mL; normal range: 25–80 ng/mL).
Vitamin D, which is also regulated by PTH, is important for helping the body absorb calcium. Low levels of the vitamin are another sign of hypoparathyroidism.
His PTH level was 10 picograms per mL (pg/mL), lower than the normal range of 11.1–79.5 pg/mL.
The man was given a standard treatment for hypoparathyroidism: oral calcium and the vitamin D supplements calcitriol and ergocalciferol.
Two weeks later, his calcium levels were 7.1 mg/dL, which is still below the normal range. His calcitriol dose was subsequently increased from once to twice a day. After one month, his calcium levels normalized at 9.1 mg/dL and then at 9.4 mg/dL two months later.
As previously planned, the man then underwent surgery for partial thyroid removal. His thyroid showed evidence of papillary carcinoma, the most common form of thyroid cancer. The cancer had not spread.
Based on characteristic features, including hypoparathyroidism and face structure abnormalities, the patient was suspected to have DGS. The researchers then used a technique called in situ hybridization to detect the characteristic deletion on chromosome 22, confirming that diagnosis.
The symptoms of DGS are often identified in newborns, making this diagnosis in adults unusual, the researchers noted. They added that papillary thyroid cancer has only been reported in DGS patients twice before.
“Our case was unique as the patient presented with hypocalcemia in adulthood, had no relevant cardiac findings, had some facial features, short stature, and scoliosis, and was later diagnosed to have papillary thyroid cancer,” the team summarized.