Mucopolysaccharidosis Type IIIB (NAGLU)

Mucopolysaccharidosis type IIIB, also known as Sanfilippo syndrome type B, is a pan-ethnic, autosomal recessive disease caused by pathogenic variants in the gene NAGLU. This disease is characterized by severe behavioral disturbances, including hyperactivity, sleep disturbances and destructive behavior. The age of onset is usually around 3 to 4 years of age. Other features include intellectual disability, enlarged liver and spleen, stiffness of the joints, hearing loss and seizures. No treatment is known. Life expectancy is generally reported to be into adolescence or early adulthood, but may be variable. No clear genotype-phenotype correlation is known.









Disease Name
 GeneGuaranteed Exons 
 Inheritance Ethnicity
 Carrier Frequency
 Detection Rate
Residual Risk

Mucopolysaccharidosis, Type IIIBNAGLU1, 2, 4-6 [6] (*11)ARCaucasian1 in 34632%0.00196850393700787
Mucopolysaccharidosis, Type IIIBNAGLU1, 2, 4-6 [6] (*11)ARAsian1 in 29856%0.0014792899408284
Mucopolysaccharidosis, Type IIIBNAGLU1, 2, 4-6 [6] (*11)ARWorldwide< 1 in 50035%0.00130039011703511