Two variants (c.571C>T and c.1259delG) in the MSTO1 gene (NM_018116.3) and one variant (c.1068dupT) in the B3GALNT2 gene (NM_152490.2) detected in both of the affected siblings were related to cerebellar atrophy and ataxia. The gene discussed is B3GALNT2; the disease is Ataxia.