Clinical and genetic analysis of 7 Chinese patients with β-ureidopropionase deficiency.

beta-Ureidopropionase (beta UP) deficiency is an autosomal recessive disease caused by abnormal changes in the pyrimidine-degradation pathway. This study aimed to investigate the mutation of beta-ureidopropionase gene (UPB1) gene and clinical features of 7 Chinese patients with bUP deficiency. We reported 7 Chinese patients with bUP deficiency who were admitted at Tianjin Children's Hospital. Urine metabolomics was detected by gas chromatography-mass spectrometry (GC-MS). Then genetic testing of UPB1 was conducted by polymerase chain reaction (PCR) method. The patients presented with developmental delay, seizures, autism, abnormal magnetic resonance imaging, and significantly elevated levels of N-carbamyl-beta-alanine and N-carbamyl-beta-aminoisobutyric acid in urine. Subsequent analysis of UPB1 mutation revealed 2 novel missense mutations (c.851G>T and c.853G>A), 3 previously reported mutations including 2 missense mutations (c.977G>A and c.91G>A) and 1 splice site mutation (c.917-1G>A). The results suggested that the UPB1 mutation may contribute to bUP deficiency. The c.977G>A is the most common mutation in Chinese population.