GM2 Synthase Deficiency (B4GALNT1) Targeted Testing

AKA: Autosomal Recessive Spastic Paraplegia-26

Short Name: B4GALNT1 Targeted

GM2 synthase deficiency is caused by variants in the B4GALNT1 gene. B4GALNT1 encodes β-1,4-N-acetyl-galactosaminyl transferase 1 (GM2 synthase), an enzyme involved in the biosynthesis of complex gangliosides. GM2 synthase deficiency is an autosomal recessive disorder characterized by onset of gait abnormalities due to lower limb spasticity and muscle weakness. A homozygous missense mutation, c.1514G>A (p.Arg505His), in B4GALNT1 was identified in Old Order Amish as the genetic cause of this condition. This test will specifically analyze the c.1514G>A variant in the Amish population.

CPT Code: 81403

Turn-Around Time: 4 weeks