Gene diagnosis and genetic analysis of a Gilbert's syndrome pedigree

Objective To diagnosis a Gilbert′s syndrome patient on the basis of gene,testing her first degree relatives for the relative gene and making an analysis of heredity.Methods By ruling out other related diseases and in accordance with the result of low calorie diet test and characteristic history,a case of Gilbert′s syndrome was diagnosed.Blood samples were collected from the patient and her first degree relatives and the genomic DNA was extracted.Amplified the relative gene UGT1A1 by polymerase chain reaction(PCR) and mutations were identified by direct sequencing.Results The patient′s unconjugated bilirubin(UCB) is higher than normal and lead to a high total bilirubin.The low calorie diet test showed that after taking the low calorie diet,the patient′s UCB was two times higher than before.The patient and her sister had a TA insertion in TATA box of the promoter region as A(TA)7TAA.Their parents are both heterozygote individuals with A(TA)6/(TA)7TAA.Conclusions The TA insertion in the promoter region of the UGT1A1 gene affects the bilirubin metabolism of the patient.The A(TA)7TAA is essential for the pathogenesis of Gilbert′s syndrome and is inherited in an autosomal recessive manner.