Expanding the phenotyping spectrum of Witteveen Kolk syndrome: first report of generalized dystonia and cerebellar ataxia.

Witteveen-Kolk syndrome (WITKOS) is an autosomal dominant disorder characterized by distinct facial features, microcephaly, short stature, intellectual disability, and subtle neuroimaging abnormalities. The syndrome is attributed to a loss of function mutation in the SIN3A gene, a member of the switch-insensitive 3 transcription regulator family. Herein, we present a 21-year-old woman with dysmorphic facial features, short stature, and a chronic, progressively worsening symmetric cerebellar ataxia, along with generalized dystonia. Whole-exome sequencing identified a heterozygous mutation in exon 7 of the SIN3A gene (c.1051 C>T, p.Pro351Ser), consistent with a diagnosis of WITKOS. Notably, dystonia has not been previously associated with this syndrome. This case underscores the clinical variability and broadens the phenotypic spectrum of WITKOS.