On this page, you will find information about a genetic change that was identified in a UDN participant. We are trying to find others with the same or similar condition.

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Date of Report

Apr 14, 2016

Full Name


Chromosome 17 (17q23.2)


The TBX2 gene codes for a transcription factor that is thought to be important in regulating development (Harrelson et al., 2004).

Database Links

GeneCards: GC17P061399

NCBI Gene: 6909

OMIM: 600747

UniProtKB/Swiss-Prot: Q13207

Clinical Significance

A change in the TBX2 gene was identified in a UDN participant, his mother, and his sister. Research is underway to see if this change is causing symptoms in this family.

The participant, an 8-year-old Caucasian male with DiGeorge syndrome (with unknown cause), was found to carry the following genetic variant in the TBX2 gene: c.59G>A/p.R20Q/p.Arg20Gln.

Gene TBX2
Inheritance Pattern autosomal dominant
Position chr17:59477596
Transcript NM_005994.3
DNA Change c.59G>A
Protein Change p.R20Q p.Arg20Gln

The patient was born with a cleft lip, cleft palate, atrial septal defect, skeletal abnormalities, and absent thymus with severe T-cell deficiency. At 6 months, he underwent a thymus transplant and was diagnosed with complete DiGeorge syndrome. He later developed inflammation of the thyroid gland with hypothyroidism, followed by hyperthyroidism. At 3 years, he was found to have early learning, communication, and social-emotional delays. At 6 years old, his cognitive ability was average, but he still had delays in verbal, math, and reading comprehension skills. While he does show some autistic behaviors, he does not meet criteria for an autism spectrum disorder. He has been diagnosed with ADHD. His mother and sister have similar, milder symptoms.

Some of his other features include:

  • Cleft lip and palate (unilateral)
  • Heart defect (atrial septal defect)
  • Absent thymus
  • No functional T-cells
  • Short neck (Klippel Feil anomaly; specific skeletal anomalies include fusion of the posterior elements of C2-C4 and fusion of the vertebral bodies of C3 and C4)
  • One shoulder blade higher than the other (Sprengel deformity)
  • Bent fingers (camptodactyly of the third and fourth fingers bilaterally)
  • Rib abnormalities (fusion of the left 4th/5th ribs and 2nd/3rd ribs)
  • Fair coarse hair
  • Asymmetric pupils (ectopia pupillae)
  • Widely spaced eyes (hypertelorism)
  • Low-set ears and cupped right ear
  • Flat nose (depressed nasal bridge and tip)
  • Short uvula
  • Sandal gap
  • Mild global developmental delay
  • Features of autism
  • ADHD
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