Objective:To analyse the clinical presentation and pathogenic gene mutations of a family diagnosed with primary familial brain calcification (PFBC).Methods:A pedigree with primary familial brain calcification was recruited. The clinical data of the proband who was admitted to the Affiliated Hospital of Guizhou Medical University in March 2020 and the family members were collected. The DNA sequence of myogenesis regulating glycosidase (MYORG) gene was detected by Sanger sequencing in the proband and some available family members.Results:The proband is a male, 30 years old. There was only one patient of PFBC in this family. The first symptom of the proband was vagueness of speech, and gradually extrapyramidal symptoms such as slow and flexible movement and advanced cognitive impairment appeared. The brain CT of the proband and his second brother showed extensive symmetrical calcifications, mainly located in the bilateral cerebellar hemispheres, basal ganglia and thalamus. A homozygous mutation in the exon 2 of the MYORG gene [c.1967T>C(p.I656T)] was identified in the proband and an asymptomatic patient. The heterozygous mutation of MYORG gene was also detected in four healthy family members.Conclusions:All patients with homozygous mutations of MYORG gene showed calcification in CT scan, and most of the lesions were located in basal ganglia, cerebellum, subcortical white matter and thalamus. Compared with the patients with autosomal dominant gene mutation, the patients with MYORG gene mutation had more extensive intracranial calcification lesions, and the pontocerebellar lesions were more common. The most common symptoms of MYORG gene mutation patients were dyskinesia, mainly tremor paralysis and unclear speech.