Background: Chromosome 6p25 deletion syndrome is a rare neurocristopathy with variable clinical features. The objective of the current study was to describe a novel phenotype for autosomal-dominant chromosome 6p25 deletion syndrome. The presentation included bilateral basal ganglia and subcortical calcifications and juvenile parkinsonism, resembling primary familial brain calcification.
Methods: Phenotypic characterization, exome sequencing, and oligonucleotide array were carried out in the index family.
Results: The index patient and her mother had a history of developmental delay, mild facial dysmorphism, Axenfield eye anomalies, slight intellectual disability, and subsequently developed levodopa-responsive parkinsonism in early adulthood. Brain-computed tomography showed bilateral basal ganglia and subcortical calcifications. Magnetic resonance imaging revealed diffuse white matter lesions. A 99mTc TRODAT single-photon emission computed tomography scan revealed bilateral dopaminergic denervation. Whole-exome sequencing and oligonucleotide array-based comparative genomic hybridization revealed a 2.27-Mb chromosome 6pter-p24 deletion, which cosegregated within the family.
Conclusions: Our findings extended the current phenotypic spectrum of chromosome 6p25 deletion syndrome. © 2020 International Parkinson and Movement Disorder Society.
Keywords: chromosome 6p25 deletion syndrome; parkinsonism; primary familial brain calcifications.
© 2020 International Parkinson and Movement Disorder Society.