Two infant sisters were born with a rare genetic condition that made their bodies unable to keep calcium levels normal, causing dangerous seizures. Doctors discovered both girls had the same genetic mutation affecting how their bodies sense and control calcium. While current treatments helped somewhat, the girls still had serious problems including kidney damage. This case study shows why doctors need better treatment options for this rare inherited condition, and highlights exciting new medicines called calcilytics that might work better in the future.

The Quick Take

  • What they studied: How doctors can better treat a rare genetic condition where babies are born with dangerously low calcium levels and seizures
  • Who participated: Two infant sisters (ages 28 days and 38 days old) with the same genetic mutation, plus their father who carried the mutation but had no symptoms
  • Key finding: Both sisters had a specific genetic change in their calcium-sensing receptor gene that caused their bodies to lose calcium and develop kidney problems, even with current standard treatments
  • What it means for you: If you have a family history of seizures in newborns or low calcium problems, genetic testing might identify this condition early. New experimental treatments may offer better options than current medications, though more research is needed.

The Research Details

This is a case report, which means doctors documented the medical history and treatment of two specific patients. The doctors carefully tracked the babies’ calcium levels, seizure episodes, and response to medications over time. They also performed genetic testing to identify the exact mutation causing the problem.

The babies received standard treatments including vitamin D supplements and calcium supplements, but doctors noticed these treatments weren’t working well enough. The babies kept having seizures and developed kidney damage despite treatment. This led doctors to investigate the genetic cause more deeply.

When genetic testing revealed both sisters had the identical rare mutation, it confirmed the diagnosis of autosomal dominant hypocalcemia type 1 (ADH1). This means the condition runs in families and only one copy of the faulty gene is needed to cause the disease.

Case reports like this one are important because they document rare diseases that doctors don’t see often. By carefully describing what happened with these two patients, doctors can help other physicians recognize and treat similar cases. This report also highlights why current treatments aren’t perfect and why new medicines are needed.

This is a detailed medical case report from a respected journal, which means it was reviewed by experts before publication. However, because it only describes two patients, the findings may not apply to everyone with this condition. Larger studies would be needed to confirm whether new treatments work better for all patients with this genetic mutation.

What the Results Show

Both infant sisters had dangerously low calcium levels at birth, which caused seizures (uncontrolled muscle shaking). The first sister had calcium levels of 5.7 mg/dL (normal is around 8.5-10.5), and her younger sister had levels of 7.7 mg/dL. Both girls also had very low parathyroid hormone levels, which is the hormone that normally controls calcium in the body.

Despite receiving vitamin D supplements and calcium supplements, both sisters continued to have seizures during febrile episodes (when they had fevers). The first sister had repeated seizures, and the second sister had three seizures during infancy. This showed that standard treatments weren’t adequately controlling their calcium levels.

Genetic testing revealed both sisters had the same mutation in a gene called CASR (calcium-sensing receptor gene). Interestingly, their father had the exact same genetic mutation but never developed symptoms, showing that the same genetic change can affect people differently.

Both girls developed nephrocalcinosis, which means calcium deposits formed in their kidneys. This happened even though doctors tried to prevent it with a medication called hydrochlorothiazide. This complication shows how difficult it is to manage this condition with current treatments.

The fact that the father carried the same genetic mutation but remained healthy is significant. It suggests that other factors—possibly environmental or related to how genes are expressed—influence whether someone develops symptoms. This variability makes the condition harder to predict and treat. The development of kidney calcium deposits in both sisters despite preventive medication highlights a major challenge in managing this condition long-term.

This case report adds to the growing understanding of autosomal dominant hypocalcemia type 1. Previous research has shown that this condition is caused by mutations in the calcium-sensing receptor gene, but this case demonstrates the real-world challenges doctors face when treating affected infants. The report emphasizes that current standard treatments, while helpful, are often insufficient for preventing serious complications like seizures and kidney damage.

This is a case report of only two patients, so the findings may not apply to everyone with this condition. Different people with the same genetic mutation might respond differently to treatments. The report doesn’t include long-term follow-up data showing how these girls fared as they grew older. Additionally, the new treatments mentioned (calcilytics) are still experimental and haven’t been tested in these patients, so we don’t yet know if they would actually help.

The Bottom Line

For families with a history of seizures in newborns or low calcium problems, genetic testing may help identify this condition early. Standard treatments (vitamin D and calcium supplements) should be started immediately if low calcium is detected, though doctors should monitor closely for breakthrough seizures. New experimental medications called calcilytics show promise but are not yet widely available—families should discuss with their doctors whether participation in research studies might be appropriate. Confidence level: Moderate (based on case reports and expert opinion, not large clinical trials).

Parents of infants with unexplained seizures or low calcium levels should ask their doctors about this condition. Families with a known history of autosomal dominant hypocalcemia should be aware of this genetic mutation. Healthcare providers treating rare calcium disorders should consider this diagnosis. People who carry the genetic mutation but don’t have symptoms may want genetic counseling before having children.

Symptoms typically appear within the first few weeks of life. With proper treatment, seizures can often be reduced within days to weeks, though complete control may take longer. Long-term management requires ongoing medication adjustments and regular monitoring. New treatments, if approved, would likely take several years to become widely available.

Want to Apply This Research?

  • If you have this condition or a family member does, track daily calcium supplement doses, any seizure episodes (date, time, duration, triggers), and calcium blood test results. Note any fevers or illnesses that might trigger calcium fluctuations.
  • Set daily reminders for calcium and vitamin D supplements at the same time each day. Keep a seizure diary noting what happened before, during, and after any episodes. Schedule regular blood tests to monitor calcium levels and adjust medications as needed.
  • Maintain a long-term log of calcium levels, medication doses, and any health changes. Share this data with your healthcare team at regular appointments. Track patterns in seizure frequency related to illness or medication changes to help doctors optimize treatment.

This case report describes a rare genetic condition in two specific patients and should not be used for self-diagnosis. If you or your child experiences unexplained seizures, low calcium levels, or symptoms of this condition, consult with a qualified healthcare provider immediately. Genetic testing and specialized medical care are necessary for proper diagnosis and treatment. The experimental treatments mentioned (calcilytics) are not yet approved for general use and should only be pursued under medical supervision. This information is educational and not a substitute for professional medical advice.