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Abstract: FR-PO599

22q11.2 Deletion Syndrome Presenting with Chronic Hypocalcemia

Session Information

  • Trainee Case Reports - III
    October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Reports

  • 1002 Genetic Diseases of the Kidney: Non-Cystic

Authors

  • Wang, Xiangling, Loma Linda University, Loma Linda, California, United States
  • Scheuner, Maren T., VA Greater Los Angeles Healthcare System, Los Angeles, California, United States
  • Fung, Enrica, Loma Linda VA, Redlands, California, United States
Introduction

22q11.2 deletion syndrome, also known as DiGeorge syndrome, is a genetic disorder characterized with distinguishing facial features and congenital anomalies. Hypocalcemia can be seen in up to 50% of patients. However, it can be challenging to reach the diagnosis in adult patients who have no or mild congenital anomalies. Here we report one female who was diagnosed with 22q11.2 deletion syndrome after symptomatic hypocalcemia for more than 40 years.

Case Description

The patient was a 66 years old Caucasian female who was the product of an uncomplicated twin pregnancy. She had frequent ear infections and nasal speech requiring speech therapy during childhood. She completed a college education and denied history of developmental delay. She experienced seizures and muscles spasms at the age of 22 while in the military service. Hypocalcemia was diagnosed and she was treated with calcium and vitamin D supplementation. Since then, she has only had episodes of muscle spasms. Family history was significant for one son with hypocalcemia and another son who died from congenital heart disease at age 6 weeks. Since her transfer to our facility in 2016, she had fluctuating levels of total serum calcium (Figure 1A) with normal range intact PTH (Figure 1B). Urine calcium excretion was low. On physical exam, she had short stature with mild facial dysmorphism, including hypertelorism and square nasal root (Figure 1C and 1D). Chromosomal microarray showed 22q11.2 deletion (Figure 1E). Diagnosis was established and she received genetic counseling about the mode of inheritance and the possibility that her son had the same diagnosis. In follow up, she continues to have intermittent asymptomatic hypocalcemia despite supplementation of calcium.

Discussion

This case highlights the importance to consider 22q11.2 deletion syndrome in chronic hypocalcemia patients who have inappropriately normal or low levels of PTH. Chromosomal microarray is available to establish the diagnosis in most cases.