What is Mucopolysaccharidosis Type IIIA (MPS3A)?
Mucopolysaccharidosis Type IIIA is a rare genetic metabolic disorder. It is often also referred to as Sanfilippo syndrome.
The disease usually presents itself post infancy in early childhood, and a major symptom is developmental regression.
The disease is progressive and affects, over time, the brain and spinal cord.
Syndrome Synonyms:
Heparan Sulfate Sulfatase Deficiency; MPS IIIA; MPS IIIA-D; MPSIII; Mucopolysaccharidosis III Mucopolysaccharidosis type III; Sanfilippo Syndrome; A Sulfamidase Deficiency
What gene change causes Mucopolysaccharidosis Type IIIA (MPS3A)?
The syndrome caused by mutations on SGSH gene, however, other subtypes of type III, should be considered as differential diagnoses.
The syndrome is a lysosomal storage disease, that affects the body’s ability to break down the large sugar molecules known as glycosaminoglycans. The buildup of these molecules in the body tissue triggers the symptoms of the syndrome. It is inherited in an autosomal recessive pattern.
Autosomal recessive inheritance means an affected individual receives one copy of a mutated gene from each of their parents, giving them two copies of a mutated gene. Parents, who carry only one copy of the gene mutation will not generally show any symptoms but have a 25% chance of passing the copies of the gene mutations onto each of their children.
What are the main symptoms of Mucopolysaccharidosis Type IIIA (MPS3A)?
Symptoms of the syndrome included delayed and regressive speech development and behavior problems. Many individuals are also diagnosed with an autism spectrum disorder. Other symptoms may include issues with sleep, seizures, chronic diarrhea, and an umbilical or inguinal hernia. A slightly enlarged liver is also often a symptom.
Physical features of the syndrome include a large head and issues with both hearing and vision.
Possible clinical traits/features:
Autosomal recessive inheritance, Ovoid thoracolumbar vertebrae, Thickened ribs, Seizure, Recurrent upper respiratory tract infections, Sleep disturbance, Splenomegaly, Synophrys, Intellectual disability, Joint stiffness, Asymmetric septal hypertrophy, Coarse hair, Coarse facial features, Dysostosis multiplex, Diarrhea, Dense calvaria, Growth abnormality, Hepatomegaly, Heparan sulfate excretion in urine, Hearing impairment, Hirsutism, Hyperactivity
How is it diagnosed?
To find out if someone has a diagnosis of Mucopolysaccharidosis Type IIA (MPS3A), it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
