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Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder resulting from biallelic mutations of ABCC2 gene, with long-term or intermittent conjugated hyperbilirubinemia being the main clinical manifestation. This paper aims to report the clinical features and ABCC2 genotypes of an infant with DJS. A 9.5-month-old male infant was referred to the hospital due to abnormal liver function discovered over 9 months. The major clinical presentation was prolonged jaundice since neonatal period. A series of biochemistry analysis revealed markedly elevated total bilirubin, conjugated bilirubin and total bile acids. The patient had been managed in different hospitals, but the therapeutic effects were unsatisfactory due to undetermined etiology. Physical examination revealed jaundiced skin and sclera, and a palpable liver 3 cm below the right subcostal margin with medium texture. The spleen was not enlarged. Genetic analysis revealed a splice-site variant c.3988-2A>T and a nonsense variant c.3825C>G (p.Y1275X) in the ABCC2 gene of the infant, which were inherited from his mother and father respectively. The former had not been previously reported. Then ursodeoxycholic acid and phenobarbital were given orally. Half a month later, as a result, his jaundice disappeared and the biochemistry indices improved. However, the long-term outcome needs to be observed. Literature review revealed that neonates/infants with DJS presented with cholestatic jaundice soon after birth as the major clinical feature, and the ABCC2 variants exhibited marked heterogeneity.

Objective: To detect potential mutations of OTC gene in a male infant affected with ornithine transcarbamylase deficiency., Methods: Genomic DNA were isolated from peripheral blood samples of family members and 100 healthy individuals. Potential mutations of the 10 exons of OTC gene were screened with PCR and Sanger sequencing., Results: A homozygous missense mutation c.917G>C in exon 9, which results in p.R306T, was identified in the infant. Sequencing of the mother and two female members of the family indicated a heterozygous status for the same mutation. The same mutation was not found in other members of the family and 100 healthy controls., Conclusion: A missense mutation c.917G>C in the OTC gene is responsible for the pathogenesis of the disease. Identification of the mutation can facilitate prenatal diagnosis and genetic counseling for the family.

VH and Vkappa genes were amplified from human ScFv B17 specific against botulinum neurotoxin serotype A (BoNTa). Gene sequence encoding 5'-terminal 12 amino acid of heavy chain constant region CH1, as a linker, linked VH and Vkappa to construct a new three-domain antibody molecule VH/Vkappa. VH/Vkappa was expressed at high level over 34% of total host cell proteins in E. coli. Recombinant protein were purified up to 95% by affinity column. As a result, recombinant VH/Vkappa could recognize and bind specific to BoNTa in ELISA. However, comparing with its parent ScFv, VH/Vkappa has higher relative affinity and stability.