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Participant 156

On this page, you will find information about a UDN participant.

Sharing information on this website is not a requirement of UDN participation. Only descriptions about participants who give explicit consent will appear here. While these participant pages are helpful to understand our participants’ stories, they do not begin to describe their diagnostic odysseys. A special thank you goes out to our participants and their families for sharing their experiences.


Female, age 1, with low T-cell lymphocyte levels (T-cell lymphopenia) and immune system abnormalities (decreased IgG level in blood)

Date of Report

Dec 20, 2019


The participant was born at 33 weeks and stayed in the NICU for three weeks. While in the NICU, she received breathing and nutrition support though a CPAP (Continuous Positive Airway Pressure) machine and NG (nasogastric) tube. She was identified by newborn screening to have very low T-cell lymphocyte levels. Since her T-cell levels are low, her immune system is weakened but the levels do not meet the criteria for a diagnosis of severe combined immunodeficiency syndrome (SCID).

The participant experienced growth deficiency as an infant, which has now resolved. A skeletal survey done at 8 months old was essentially normal. She also has a history of excess calcium in the blood (hypercalcemia).

The participant is currently 22 months old and receives treatment to boost her immune system (Hizantra).

Symptoms / Signs
  • Immune system abnormalities (decreased IgG level in blood)
  • Low white blood cell levels (leukopenia)
  • Low lymphocyte levels (lymphopenia)
  • Excess calcium in the blood (infantile hypercalcemia)
Current Treatments
  • Hizantra – immune system support
Prior Treatments
  • Intravenous immunoglobulin, prophylactic antibiotics – immune system support
Considered treatments
Previously Considered Diagnoses
  • Chromosomal breakage syndromes
  • Primary immunodeficiency diseases (PIDD)
  • Severe Combined Immunodeficiency syndrome (SCID)
Other Photographs
Genetic Variants of Interest

In 2021, clinicians and researchers identified the following genetic change to be causing the participant’s symptoms:

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
Autosomal dominant
Chr17: 1782557

If this participant sounds like you or someone you know, please contact us!


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