A novel variant of the POLR3A gene in a Chinese patient with POLR3-related leukodystrophy.

Haojun Yang, Zhongling Wu, Xiaolei Li, Yuanxin Huang, Jing Li, Fang He, Li Feng, Bo Xiao, Weiting Tang

Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology 2023 Sep

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POLR3-related leukodystrophy is a group of rare neurodegenerative disorders characterized by degeneration of the white matter with different combinations of major clinical features. An 18-year-old lady was admitted for no menstruation since childhood. She gradually developed slight symptoms, such as choking after drinking water and unsteady walking in the last 2 years. Furthermore, her test scores and response capability were far lower than that of her peers. Physical examination revealed her to be of a slightly short stature, with stiff expressions and bilateral breast enlargement. She revealed clumsy movements when examined for ataxia, with an SARA score of 9. The laboratory data revealed a decreased level of estradiol, FSH, and LH, with a MoCA score of 7. Conventional karyotype analysis revealed a 46 XX 9qh + karyotype. Ultrasound indicated primordial uterus (19 × 11 × 10 mm). Brain MRI showed bilateral cerebral hemisphere myelin dysplasia, brain atrophy, thin corpus callosum, and small pituitary gland with uneven reinforcement and enlarged ventricles. Exome sequencing exhibited two missense mutations in the POLR3A gene (c.3013C > T and c.1757C > T), which were inherited from her mother and father, respectively. Collectively, we identified novel compound heterozygous mutations of the POLR3A gene that caused POLR3A-related hypomyelinating leukodystrophy with hypogonadism in the patient combined with the clinical presentation, MRI brain pattern, and medical exome sequencing. The complexity of clinical phenotypes and heterogeneity of genotypes raise new challenges in genetic diagnoses. This study will further aid our understanding of POLR3A-related leukodystrophy and promote further analysis of phenotype-genotype correlations of related diseases. © 2023. Fondazione Società Italiana di Neurologia.

Citation

Haojun Yang, Zhongling Wu, Xiaolei Li, Yuanxin Huang, Jing Li, Fang He, Li Feng, Bo Xiao, Weiting Tang. A novel variant of the POLR3A gene in a Chinese patient with POLR3-related leukodystrophy. Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. 2023 Sep;44(9):3363-3368