background participants

Participant 041

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 11, with intellectual disability, absent speech, and very happy disposition caused by a change in the SMARCC2 gene.

Date of Report

Nov 30, 2017


At 11 months old, the participant’s parents noticed that he was delayed developmentally and was unable to sit up on his own. He began walking with a walker at age 3. He was evaluated by neurology and received a brain MRI that showed an abnormality of brain white matter (periventricular leukomalacia). However, follow-up brain MRIs have been normal.

At age 8, the patient started to be able to feed himself using a pincher grasp. Currently he is nonverbal and uninterested in signing or using a communication device.

Overall, he is a very pleasant and happy child and has never developed stranger anxiety.  His demeanor is reminiscent of Angelman syndrome, but his other symptoms do not fit with this condition.

Symptoms / Signs
  • Global developmental delay
  • Intellectual disability
  • Absent speech
  • Abnormal social behavior
  • Conspicuously happy disposition
  • Agitation
  • Repetitive behaviors (stereotypic behavior)
  • Delayed cranial suture closure
  • Abnormality of brain white matter (periventricular leukomalacia)
  • Loss of skin color (generalized hypopigmentation)
  • Downslanted eyes (downslanted palpebral fissures)
  • Eyes turned outward (exotropia)
  • Increased distance between eyes (hypertelorism)
  • Abnormal tear production (alacrima)
  • Thin upper lip (thin vermilion border)
  • Broad length between end of nose and top of lip (broad philtrum)
  • Large ear (macrotia)
  • Recurrent hand flapping
  • Tissue bulge in abdomen (inguinal hernia)
  • Decreased tone (muscular hypotonia)
  • Constipation
  • Abnormal walking (broad-based gait)
  • Toes fused together (2-3 toe syndactyly)
Current Treatments
Prior Treatments
Considered treatments
Previously Considered Diagnoses
  • Angelman syndrome
  • Fragile X syndrome
  • Microdeletion/duplication syndrome
  • Mowat-Wilson syndrome
  • Pitt Hopkins syndrome
  • Prader Willi syndrome
  • Williams syndrome
Other Photographs
Genetic Variants of Interest

Clinicians and researchers have identified the following genetic change to be causing the patient’s symptoms (Machol et al, 2018):

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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