"CDC73-associated (hyperparathyroid-jaw tumor) syndrome" What Is It?
The CDC73-associated (hyperparathyroid-jaw tumor) syndrome (HPT-JT) is a rare disease caused by mutations, i.e. genetic changes, in the CDC73 gene (also HRPT-2). Those affected have a significantly increased risk of parathyroid tumors associated with hyperparathyroidism (primary hyperparathyroidism, PHPT), bone tumors (ossifying fibromas) in the upper and lower jaw, and kidney and uterine tumors.
How Is "CDC73-associated (hyperparathyroid-jaw tumor) syndrome" Diagnosed?
Clinical Diagnostics
- PHPT AND ossifying fibroma(s) of the upper and/or lower jaw
- PHPT AND close relative with HPT-JT syndrome
- Ossifying fibroma(s) of the upper and/or lower jaw AND a close relative with HPT-JT syndrome
Diagnosis confirmation
The clinical diagnosis is made by blood tests (measurment of calcium and parathyroid hormone) and diagnostic imaging (X-ray of the jaw, ultrasound of the kidneys and pelvis).
Genetic Diagnostics
The diagnosis of ‘HPT-JT’ is confirmed by the detection of a mutation, i.e. a genetic change in the CDC73 gene.
How High Is the Risk of Cancer?
Primary hyperparathyroidism
- Main finding in HPT-JT and found in up to 95% of patients
- Usually caused by a single benign parathyroid tumour, a second one can occur at the same time or with a time delay
- In 10-15% of cases, PHPT is caused by a malignant parathyroid carcinoma
- Occurs mostly in late adolescence to early adulthood
Jaw tumours
- In 30-40% of HPT-JT patients
- Partly space-occupying lesion with increase in size, partly only detectable on X-ray
- Can interrupt tooth eruption from the jaw and/or impair breathing
Kidney diseases
- 20% of HPT-JT patients have kidney involvement: Mostly cysts, hamartomas (tumour-llike, benign tissue change) or, more rarely, Wilms’ tumours (malignant kidney tumour)
- Cystic diseases can be a few small cysts, but also kidneys interspersed with cysts on both sides
Tumours of the uterus
- Found in about 75% of female HPT-JT patients, average age at diagnosis is 35 years
- Can be benign or malignant
- The following can occur: Endometriosis, adenofibroma, endometrial hyperplasia, leiomyoma and adenosarcoma
What Is Known About the Development of "CDC73-associated (hyperparathyroid-jaw tumor) syndrome"?
CDC73-associated (hyperparathyroid-jaw) syndrome is caused by a mutation, meaning a genetic change in the CDC73 gene. This gene codes for the protein parafibromin, which plays a role in the duplication of genetic material. If the CDC73 gene is present in an altered form, the parafibromin protein can no longer function correctly and tumours develop.
It is not yet known how frequently HPT-JT syndrome occurs. What is known is that the disease can be passed on from parents to their children. The inheritance is autosomal dominant.
Is There Any Form of Treatment Available?
Primary hyperparathyroidism
As there is usually only a single parathyroid tumour as the cause of PHPT, a minimally invasive procedure to remove the parathyroid tumour is preferred. This includes:
- Imaging before the operation (ultrasound, scintigraphy with 99mTc, CT/MRI) to localise the tumour
- Measurement of parathyroid hormone (hormone produced by the parathyroid gland) to check that the gland with hyperfunction has been removed
If a malignant parathyroid carcinoma is present, the parathyroid glands, including the equilateral thyroid lobe, should be removed.
Jaw Tumours
If possible, the tumour should be completely removed. Drug-based approaches for tumours that cannot be completely removed are not yet known. Due to the risk of recurrence, patients should attend follow-up examinations.
Kidney diseases
In the case of cystic diseases, an individualised therapy must be determined depending on the extent and appearance. There are no specific guidelines for HPT-JT patients.
Tumours of the uterus
In the case of uterine tumours, an individual therapy must be determined depending on the extent and appearance. There are no specific guidelines for HPT-JT patients.
Diagnose CDC73-associated (hyperparathyroid-jaw tumor) syndrome. Wie geht es weiter?
Nach der Diagnose wenden Sie sich bitte unbedingt an eine:n Spezialist:in für dieses Krebsprädispositionssyndrom. Im folgenden Abschnitt schildern wir Ihnen, ob Untersuchungen zur Krebsfrüherkennung oder andere Maßnahmen erforderlich sind und wie diese erfolgen sollten. Zudem geben wir Ihnen ein paar Tipps, was Sie selber tun können. Bei Fragen wenden Sie sich bitte jederzeit an uns oder Ihren behandelnden Arzt oder Ihre behandelnde Ärztin.
Diagnosis of "CDC73-associated (hyperparathyroid-jaw tumor) syndrome" What's Next?
Once you have been diagnosed, please be sure to consult a specialist for this cancer predisposition syndrome. In the following section, we will tell you whether cancer screening tests or other measures are necessary and how they should be carried out. We also give you a few tips on what you can do yourself. If you have any questions, please contact us or your doctor at any time.
Medical Measures for Early Detection
To date, there are no standardised screening recommendations for patients with CDC73 mutations. Based on the currently available literature, the following is suggested:
- Blood test annually, from 5-10 years of age
- Regular ultrasound of the parathyroid glands to detect the rare non-functional parathyroid carcinoma associated with a CDC73 mutation
- X-ray of the jaw at least every 5 years, regular professional teeth cleaning from the age of 10
- Ultrasound of the kidneys at least every 5 years, starting from the time of diagnosis. Creatinine in the blood should be determined regularly in patients with known cysts.
- Women of childbearing age should undergo regular gynaecological examinations. A pelvic ultrasound should be performed if there are any abnormalities in menstruation, possibly followed by imaging examinations (CT or MRI).
CDC73-associated (hyperparathyroid-jaw tumor) syndrome – What You Can Do Yourself
You should pay attention to this
Hyperparathyroidism can manifest itself as bone pain. In addition, kidney or gallstones can occur, which can cause pain in the flank area or upper abdomen. Kidney cysts can also cause pain in the flank area. Urinary abnormalities or urinary tract infections can also occur. Tumours of the uterus are usually noticeable due to bleeding or changes in menstruation. Tumours of the jaw can cause the teeth to fail to erupt from the jaw, swelling and pain.
If you notice any of the above symptoms or other complaints or abnormalities, a visit to the doctor is urgently recommended.
Further Information
Unfortunately, we are not yet aware of any support groups for patients with CDC73-associated (hyperparathyroid-jaw tumour) syndrome. As soon as we have new information, we will add it. However, patients can register for the KPS register at any time or have this done by the doctors looking after them.
Any Further Questions?
You can reach us by email and telephone. You can also visit us in person during our consultation hours. Further information can be found on our contact page.
