B4GALNT1
Function
Involved in the biosynthesis of gangliosides GM2, GD2, GT2 and GA2 from GM3, GD3, GT3 and GA3, respectively.
Involvement in disease
Spastic paraplegia 26, autosomal recessive
SPG26
A form of spastic paraplegia, a neurodegenerative disorder characterized by a slow, gradual, progressive weakness and spasticity of the lower limbs. Rate of progression and the severity of symptoms are quite variable. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. SPG26 is a complicated form characterized by onset in the first 2 decades of life of gait abnormalities due to lower limb spasticity and muscle weakness. Some patients have upper limb involvement. Additional features include intellectual disability, peripheral neuropathy, dysarthria, cerebellar signs, extrapyramidal signs, and cortical atrophy. The disorder is slowly progressive.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Sphingolipid metabolism.
Sequence Similarities
Belongs to the glycosyltransferase 2 family.
Cellular localization
- Golgi apparatus membrane
- Single-pass type II membrane protein
Alternative names
GALGT, SIAT2, B4GALNT1, (N-acetylneuraminyl)-galactosylglucosylceramide, GM2/GD2 synthase, GalNAc-T