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Participant 101

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Female, age 4 with seizures, global developmental delay, and underdeveloped optic nerve (optic nerve hypoplasia)

Date of Report

Dec 19, 2018


The participant began to experience tremors at 4 months and concerns were raised for global developmental delay when she failed to meet developmental milestones. Early in life, she had episodic fevers, frequently requiring hospitalization, and staring spells thought to be seizures (absence seizures). After evaluation by neurology, she had an abnormal EEG and was identified to have low muscle tone in the arms and legs (appendicular hypotonia). At 15 months she was diagnosed with an underdeveloped optic nerve (optic nerve hypoplasia) and has poor depth perception. She also has episodes of hyperventilation, teeth grinding (bruxism), and stereotypical hand wringing.

Symptoms / Signs
  • Seizures (absence seizures)
  • Abnormal brain imaging (evidence of white matter injury/gliosis in the white periatrial white matter, asymmetric relative to the right side)
  • Underdeveloped optic nerve (optic nerve hypoplasia)
  • Low muscle tone in arms and legs (appendicular hypotonia)
  • Global developmental delay
  • Autism
  • Absent speech
  • Episodic fever
  • Hyperventilation and breath holding episodes
  • Stereotypical hand wringing
  • Mild eye folds (epicanthus)
  • Underdeveloped ears (microtia)
  • Teeth grinding (bruxism)
  • Enlarged tonsils
  • Curved pinky finger (clinodactyly of the 5th finger)
  • Foot abnormality (metatarsus adductus)
  • Broad big toe (hallux)
  • History of difficulty breathing (apnea)
  • Small, abnormal teeth (dysplastic teeth)
  • Gastroesophageal reflux
  • Constipation
  • Sleep disturbance
Current Treatments
  • Ankle foot orthoses (AFOs)
  • Melatonin – sleep disturbance
  • Lamictal – seizures
  • Clonidine
Prior Treatments
  • Tonsillectomy – enlarged tonsils
Considered treatments
Previously Considered Diagnoses
  • Angelman syndrome
  • Genetic neurologic disorder
  • Hypothalamic disorder
  • Microdeletion/duplication disorder
Other Photographs
Genetic Variants of Interest

Clinicians and researchers are investigating the following genetic changes to see if they are causing the patient’s symptoms:

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
c.4257C>G (mosaic)

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


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