Publication

The Phenotypic Variation of a Family and the Role of Heterozygosity

Journal Paper/Review - Sep 16, 2019

Units
PubMed
Doi

Citation
Stark R, Walch J, Kägi G. The Phenotypic Variation of a Family and the Role of Heterozygosity. Mov Disord Clin Pract 2019; 6:700-703.
Type
Journal Paper/Review (English)
Journal
Mov Disord Clin Pract 2019; 6
Publication Date
Sep 16, 2019
Issn Electronic
2330-1619
Pages
700-703
Brief description/objective

Background
Parkinson's disease (PD) is a common neurodegenerative disorder with both sporadic occurrence and Mendelian heredity, as it is true for autosomal recessive -related PD (PARK-). related PD is characterized by early onset, slow progression, frequent lower limb dystonia, and a robust response to levodopa. Clinicians are increasingly confronted with heterozygous PD patients mimicking dominant inheritance. Nevertheless, the exact clinical implications of heterozygosity are not fully understood.

Cases
We present an illustrative PARK- family with 2 affected sisters (compound heterozygous) and their father (heterozygous). One sister expresses the classical phenotype, whereas the other has isolated jerky tremor. The father has left-sided action tremor of the hand with some dystonic posturing without clear bradykinesia and normal DaTSCAN.

Conclusion
This case series illustrates the phenotypic variability in -related PD with 1 classical phenotype and 1 patient with isolated jerky tremor. Unilateral hand tremor of the heterozygous father could mislead genetic testing by mimicking dominant inheritance.