Signs of Sanfilippo can be present in the newborn period, but often go unnoticed without newborn screening.
Most symptoms begin to be recognized between 1 and 6 years of age when the child begins showing signs of developmental delay.
Common Symptoms
Early Features:
- Transient Tachypnea Of Newborn*
- Coarse Facial Features*
(frontal bossing/prominent forehead, full lips, and nose) - Prominent, thick eyebrows*
- Persistent Hirsutism*
- Macrocephaly*
- Speech & Developmental Delays+
- Hearing Loss+
(typically high-frequency, sensorineural hearing loss) - Recurrent Ear/Sinus Infections
- Chronic Upper Respiratory Congestion
- Challenging Behaviors
(hyperactivity, impulsivity, poor sense of safety, difficulty cooperating) - Features of Autism
(speech regression, mouthing/oral fixation, loss of interest in social interactions, repetitive speech/behaviors) - Sleep Disturbances
(difficulty going to sleep; frequent nighttime waking, often with disruptive behaviors; difficulty getting back to sleep) - Diarrhea/Chronic Loose Stools
- Umbilical/Inguinal Hernia
- Enlarged Liver/Spleen
Later Features:
- Continued Coarsening of Facial Features
- Development of features of Autism
- Progressive Intellectual Disability
- Brain Atrophy (
shrinking of brain tissue from loss of nerve cells) - Seizures/Movement Disorders
- Behavioral problems
- Hyperactivity
- Impulsivity
- Loss of Ambulation
- Loss of Oral Feeding
(chewing and swallowing problems) - Enlarged Liver/Spleen
- Hearing Loss
(typically high-frequency, sensorineural hearing loss) - Early Death
*The most-specific indicators of Sanfilippo syndrome in infants, as reported in Escolar C, Bradshaw J, Byers V, et. al, 2020, Development of a Clinical Algorithm for the Early Diagnosis of Mucopolysaccharidosis III. Journal of Inborn Errors of Metabolism & Screening. 2020, Volume 8: e20200002.
+Early neurological features of Sanfilippo.
Progression of Coarse Facial Features in Sanfilippo
These images compare the progression of coarse facial features of children with Sanfilippo syndrome, compared to their unaffected siblings. These images are from Escolar C, et. al, 2020, Development of a Clinical Algorithm for the Early Diagnosis of Mucopolysaccharidosis III. Journal of Inborn Errors of Metabolism & Screening. 2020, Volume 8: e20200002..
Average Age at Diagnosis of Patients With Sanfilippo
| Sanfilippo Type | No. of Diagnoses+ | Median Age (Range)++ |
|---|---|---|
| Type A | 31 | 3.5 (0.2-17.1) |
| Type B | 17 | 3.5 (0.0-21.4) |
| Type C | 3 | 10.7 (5.7-12.0) |
| Type D | 4 | 3.1 (0.4-7.4) |