background participants

Participant 155

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 5 with seizures, ataxia, brain abnormalities, small head size (postnatal microcephaly), and severe expressive and receptive language delay

Date of Report

Dec 16, 2019


At 6 months of age, the participant’s parents noticed she was not rolling over or reaching or playing with toys. They also noticed abnormal eye movements. She was eventually diagnosed with nystagmus and oculomotor apraxia.

At 15 months, the participant experienced her first seizure when she had a fever (simple febrile seizure) and had a non-febrile seizure soon after (generalized tonic-clonic seizure). Brain imaging showed multiple brain abnormalities (cerebellar atrophy, small cerebral cortex, hypoplasia of the brainstem).

Currently, the participant has difficulty controlling voluntary movements (limb ataxia, truncal ataxia, chorea) and is nonverbal. She utilizes an eye gaze device to communicate and can express likes and dislikes and say hello and goodbye.

Symptoms / Signs
  • Global developmental delay
  • Severe expressive and receptive language delay
  • Difficulty controlling voluntary movements (limb ataxia, truncal ataxia, chorea)
  • Low muscle tone (generalized hypotonia)
  • Seizures (generalized tonic-clonic seizures, simple febrile seizures)
  • EEG abnormality (presence of slow background activity and focal epileptiform discharge in bilateral cerebral hemisphere)
  • Brain abnormalities (cerebellar atrophy, small cerebral cortex, hypoplasia of the brainstem)
  • Small head size (postnatal microcephaly)
  • Horizontal, repetitive, uncontrolled eye movements (nystagmus)
  • Inability to control voluntary eye movement (oculomotor apraxia)
  • Farsightedness (hypermetropia)
  • Involuntary nodding of head (titubation)
  • Gastroesophageal reflux
  • Increased ammonia levels in blood (mild hyperammonemia)
  • Increased alanine levels in blood (mild hyperalaninemia)
  • Mitochondrial Childhood Disorder
Current Treatments
  • Carnitor
  • Omeprazole, Rantinidine – gastroesophageal reflux
  • Topomax, Epidiolex, ketogenic diet – seizures
  • Vitamin B1, Vitamin B2, CoQ 10
Prior Treatments
  • Keppra, Lamictal, Banzel – seizures
Considered treatments
Previously Considered Diagnoses
  • Angelman syndrome
  • Metabolic condition
  • Microdeletion/duplication condition
Other Photographs
Genetic Variants of Interest

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

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
Autosomal recessive
Chr5:157158585/ Chr5:157159997
c.137C>A/ c.313G>A

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


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