background participants

Participant 144

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 3, with developmental delay, staring spells, low muscle tone (hypotonia), and uncontrolled eye movements (nystagmus)

Date of Report

Sep 25, 2019


The participant was born at 38 weeks. During the pregnancy, there was less amniotic fluid than normal (oligohydramnios). Around 8 months old, the participant’s parents noticed delays in her development and that she would fall over frequently. Since then, she has made slow developmental progress.

At 10 months old, the participant was seen by Neurology and was noted to have low muscle tone (hypotonia). Around the same time, she was found to have uncontrolled eye movements (nystagmus) as well as staring spells. During these starting spells, her eyes roll back, and she is unresponsive for about 10 seconds. These continue to happen daily, up to 10 times per day.

At 15 months old, the participant said her first word, and currently can say about 10-15 words. She has significant balance issues and is currently unable to stand or walk independently.

The participant attends preschool 3 days a week and has an Individualized Education Program (IEP). She is a very social and happy child.

Symptoms / Signs
  • Global developmental delay
  • Expressive language delay
  • Failure to thrive
  • Abnormality of coordination
  • Difficulty walking (gait disturbance, gait imbalance)
  • Decreased muscle mass
  • Low muscle tone (generalized hypotonia)
  • Large head size (macrocephaly)
  • Narrow head shape (dolichocephaly)
  • Facial differences (triangular face, fused teeth)
  • Horizontal, repetitive, uncontrolled eye movements (nystagmus)
  • Drooping eyelids (congenital bilateral ptosis)
  • Staring gaze
  • Seizures (febrile seizures)
  • Constipation
Current Treatments
  • Occupational, physical, and speech therapy
Prior Treatments
  • Amoxicillin – ear infection
Considered treatments
Previously Considered Diagnoses
  • Angelman syndrome
  • Metabolic condition
  • Mitochondrial disorder
  • Prader-Willi syndrome
Other Photographs
Genetic Variants of Interest

Clinicians and researchers are investigating the following genetic change to see if it is causing the participant’s symptoms:

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
see gene page
see gene page
see gene page
see gene page
see gene page

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


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