Abstract:

Objective To conduct the genetic analysis of a family with one patient suffering from juvenile Parkinson’s disease （JP） and discuss the clinical manifestations， genetic mutation characteristics， and treatment plans prompted by PRKN gene compound heterozygous mutations，and to enhance the clinicians’ awareness of this disease. Methods The clinical data of one patient with JP caused by PRKN gene mutations was analyzed， the clinical manifestations and genetic mutation features of the patient were summarized， and the related literatures were reviewed. Results The patient， a 16-year-old male， was admitted to the hospital due to unstable gait， trembling limbs with rigidity in both lower limbs for three years.The examination results revealed a panic gait， clear consciousness， fluent speech， normal muscle strength in limbs， increased “gear-like” muscle tone in both upper limbs， and “lead-pipe” rigidity in both lower limbs；the sensory functions and tendon reflexes were normal. The head， neck， and thoracic magnetic resonance imaging （MRI） results showed no abnormalities. ¹⁸F-fluorodeoxyglucose （¹⁸F-FDG） positron emission tomography/computed tomography （PET/CT）results showed that the head size and shape were normal， the glucose metabolism in the left cerebellum and middle temporal gyrus was slightly decreased， and the glucose metabolism in bilateral thalami， right frontal lobe， parietotemporal lobe， and left medial frontal lobe was increased. The dopamine transporter （DAT） PET/CT results showed that there was no radioactive distribution in the brain cortex and the DAT distribution in the posterior part of both striata was decreased. The whole-exome sequencing results showed the patient had two PRKN gene mutations，such as codons c.8T>A and c.850G>C compound heterozygous mutations，and each mutation was from one parent；the patient’s father carried the c.8T>A mutation， the patient’s mother carried the c.850G>C mutation， and the patient’s sister had the same genetic mutation site as the patient’s father. Conclusion PRKN gene compound heterozygous mutations may be the basis of the disease in this family. Identification of the mutation c.8T>A expands the mutation spectrum of the PRKN gene， and provides the valuable information for the research on the pathogenic genetic mutations of the JP patients.

Key words: Juvenile, Parkinson’s disease, PRKN gene, Gene mutation