Novel mutations in a Chinese family with two patients with succinic semialdehyde dehydrogenase deficiency

• Published in: Gynecological endocrinology Vol. 36; no. 10; pp. 1 - 933
• Main Authors: Chen, Xiao-Dan, Lin, Yun-Ting, Jiang, Min-Yan, Li, Xiu-Zhen, Li, Duan, Hu, Hao, Liu, Li
• Format: Journal Article
• Language: English
• Published: England 02.10.2020
• Subjects: SSADH deficiency; ALDH5A1 gene; novel mutation; whole exome sequencing
• ISSN: 0951-3590; 1473-0766
• DOI: 10.1080/09513590.2020.1744555

A considerable proportion of pediatric disease burden is mainly caused by inborn errors of metabolism. Succinic semi-aldehyde dehydrogenase (SSADH) deficiency is an unusual disorder of the gamma-aminobutyric acid metabolism. Till date, very few cases have been reported in China. Trio-WES was used to characterize the gene in two children of a Chinese family, who presented with seizures, psychomotor delay, development regression, borderline cognition, hypotonia, and harbored the compound heterozygotes NM_001080.3: c.1321G > A (p. Gly441Arg) and c.727_735del (p. Leu243_Ser245del). The former has been reported earlier (rs1041467895), whereas the latter is novel. Amino acid coding at highly conserved amino acid residues was observed to be altered by both mutations. This structural impairment influenced the enzyme structure as indicated by the protein modeling. Cerebral magnetic resonance imaging of the proband and her brother showed excessive gap in the cerebrum and abnormal signals in the bilateral frontal lobe, bilateral basal ganglia, and cerebral foot. Elevated levels of Gamma-hydroxybutyric aciduria were found in their patients on urine organic acid analysis. Our findings contribute to the current knowledge of missense and deletion mutations associated with SSADH deficiency.