background participants

Participant 040

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 40, with mucopolysaccharidosis type IIIC (Sanfilippo C) caused by genetic changes in the HGSNAT gene

Date of Report

Nov 27, 2017


The participant’s parents became concerned with his development when he was about 3-4 years old. At this time, his speech was delayed and he was learning a bit slower than other children in school. He was able to graduate from high school, but had difficulty with college level work. Otherwise he was generally healthy and had normal development. He moved into a group home during a transitional period in his mid-twenties in which his frustration and inability to perform created job issues and strained family relationships.

At the age of 34, he had a trance-like episode with staring and drooling. Initially this was thought to be a seizure, but an EEG was normal. This episode marked the start of a significant decline where the participant lost his ability to process information and communicate complex ideas. He also started to experience a significant physical decline with poor coordination and difficulty with daily activities.

Symptoms / Signs
  • Intellectual disability
  • Lack of insight
  • Attention deficit hyperactivity disorder
  • Depression
  • Involuntary muscle movements (dyskinesia)
  • Motor disorder due to brain damage (apraxia)
  • Poor coordination
  • Loss of brain tissue (cerebral atrophy)
  • Memory impairment
  • Reduced consciousness/confusion
  • Abnormality of eye movements
  • Language impairment (aphasia)
  • Repetitive vocalizations (echolalia)
  • Slurred speech
  • Shuffling walk (shuffling gait)
  • Obstructive sleep apnea
Current Treatments
  • Acetaminophen- pain
  • Cerovite tabs- vitamin deficiency
  • Hydrocortisone- rash
  • Levocetrizine- allergies
  • Mineral oil- earwax
  • Minocycline- infections
  • Mirtazapine and Citalopram- depression
  • Triamcinolone ointment- sores
Prior Treatments
Considered treatments
Previously Considered Diagnoses
  • Fragile X syndrome
  • Lyme disease
  • Niemann-Pick disease type C
  • Syphilis
Other Photographs
Genetic Variants of Interest

Clinicians and researchers have identified the following genetic changes to be causing the patient’s symptoms:

Inheritance Pattern
Position (hg19)
DNA Change
Protein Change
Autosomal recessive
chr8:g.43037317G>A & g.43047463G>T
c.1042G>A & c.1267G>T
p.Val348Met & p.Gly423Trp

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


The information provided here is based on individual patient experiences. This information is not meant to substitute for advice of a qualified health care provider. Please do not use this information to diagnose or develop a treatment plan for a health problem or disease without consulting a qualified health care provider.

Any mention of products or services is not meant as a recommendation of the products or services. Please discuss any options with a qualified health care provider.

Developments in medical research may impact the information that appears here. No assurance can be given that the information in this site will include the most recent findings or developments.

The use of any information provided on this site is solely at your own risk.