background participants

Participant 006

increased weight
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.


Male, age 3, with low muscle tone (hypotonia), developmental delay, and increased weight caused by a change in the PRKAR1B gene

YouTube channel MIT Technology Review article

Date of Report

Aug 05, 2016


This patient is 3 years old and has low muscle tone (hypotonia), developmental delay, and increased weight. During the first trimester of pregnancy, there was a concern of increased amniotic fluid (polyhydramnios). The patient was born by C-section at 38 weeks and his birth weight was 6 pounds 14 ounces. He had trouble gaining weight initially, but then had issues of being overweight starting at 6 months. A muscle biopsy was performed and showed myofiber smallness mostly affecting type 1 fibers, which is consistent with dysmaturation myopathy. Overall, the patient has been in good health.

Developmentally, the patient has been making progress with therapies he is receiving. His receptive language is good and sensory processing issues are improving. However, he does seem to be regressing in spoken language. In June of 2014, his parents reported that he had about 40-50 words, but now he has very few.

Symptoms / Signs
  • Low muscle tone (hypotonia)
  • Muscle weakness
  • Increased body weight
  • Obesity
  • Delayed motor development
  • Delayed speech and language development
  • Sensory impairment
  • Simple febrile seizures
  • Poor coordination
  • Developmental regression
  • Cow milk allergy
  • Sleep apnea (obstructive)
  • Eczema
  • Asthma
  • Head twists to one side (torticollis)
  • Slight unibrow (synophrys)
  • Eye folds (epicanthus)
  • Cross-eyed (strabismus)
  • Astigmatism
  • Slightly upturned nose (anteverted nares)
  • Flat bridge of nose (depressed nasal bridge)
  • Low-set, posteriorly rotated ears
  • Chewing difficulties
  • Inverted nipples
  • Small (hypoplastic) toenails
  • Short finger bones
Current Treatments
  • Proventil, Ventolin, Pulmicort, Duoneb- asthma
Prior Treatments
Considered treatments
Previously Considered Diagnoses
  • Prader Willi syndrome
  • Microdeletion/duplication syndrome
Other Photographs
Genetic Variants of Interest

In 2021, clinicians and researchers identified the following de novo genetic change to be causing the participant’s symptoms (Marbach et al., 2021):

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
Autosomal dominant

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


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