Intrafamilial variability in a polish family harbouring a frameshift THAP1 mutation

We report a family of Polish origin with a heterozygous mutation in the THAP1 gene. Sanger sequencing of the entire coding region of the THAP1gene identified a heterozygous frameshift mutation (c.377_378delCT) in exon 3, segregating both in the affected mother and daughter. The same frameshift deletion has been described only in three other patients with young onset generalized dystonia.It is important to report new families with THAP1 mutations in order to better delineate the phenotypic spectrum of DYT6-dystonia, which lacks clear correlates with mutation types and expands well beyond the early onset, predominantly cranial-cervical presentation initially associated to this condition.