Mucopolysaccharidosis type III, also known as Sanfilippo syndrome, is a multisystem lysosomal storage disorder. Mutations in the genes GNG, HGSNAT, NAGLU, and SGSH encode the synthesis of enzymes involved in the catabolism of mucopolysaccharides (a large sugar molecule). The deficiency of the enzymes leads to the accumulation of the substrate. It primarily affects the central nervous system causing neurological problems, including autism, intellectual disability, behavioral problems, sleep disturbances, developmental regression, and seizures. The disease usually decreases the lifespan of the patient to two or three decades.
Since the disease is genetic in origin, there is no complete cure yet. Symptomatic and supportive treatment helps improve the quality of life. They are as follows:
1. Seizures: Anti-epileptic medicines such as carbamazepine, clobazam, lamotrigine, levetiracetam, oxcarbazepine, phenytoin, sodium valproate, topiramate, lacosamide, and zonisamide.
2. Neurodevelopmental delays: Supportive therapies include speech therapy, physiotherapy, and occupational therapy.
3. Psychiatric or behavioral problems: Risperidone is a preferable drug to treat hyperactivity.
Antipsychotic drugs may also help.
A physically safe environment at home for children prevents secondary injuries due to aggressive and hyperactive behavior.
4. Sleep disorder: Melatonin or Melatonin agonist (ramelteon) can treat sleep disturbances. Other medicines such as benzodiazepine and z-drugs can help insomnia with sleep onset issues.
Pulmonologist involvement is necessary for sleep apnea.
5. Skeleto-muscular problems: Physical therapy and hydrotherapy for joint stiffness. Vitamin D therapy for low bone mineral density.
6. Hearing loss: Ear tube insertion and hearing aid use are viable options for patients with hearing loss.
Neurological manifestations: autism, intellectual disability, behavioral problems, sleep disturbances, developmental regression, seizures (in later stages),Systemic manifestations: joint stiffness, contractures, scoliosis, hip dysplasia, respiratory tract and sinopulmonary infections, cardiac disease, hearing loss,In children: loss of motor and cognitive skills, verbal skills (between 10 and 15 years), Coarse and thick hair, Dysmorphisms (alae nasi, lips, and ear helices or lobules and macroglossia),Hyperactivity and aggressive behavior (decreases with age),Gastrointestinal problems: episodic diarrhea, problems with chewing and swallowing food, increasing risks for aspiration pneumonia and weight loss, Inguinal and umbilical hernias,Atrophy of the optic nerve and retinal degeneration at later stages
Autism spectrum disorder,Klüver-Bucy syndrome,Carpal tunnel syndrome
Melatonin and melatonin agonists (sleep disturbances), risperidone(for psychiatric disorder),Anti-epileptic medicines such as carbamazepine, clobazam, lamotrigine, levetiracetam, oxcarbazepine, phenytoin, sodium valproate, topiramate, lacosamide, and zonisamide