Analysis of UGT1A1 Polymorphism and Clinical Risk Factors for Neonatal Jaundice in Chinese Tibetan Newborns: Comparison with Han Newborns

Abstract Background Neonatal jaundice is a common health issue in infants. Tibetan newborns living at high altitudes may face greater risks due to chronic hypoxia and potential genetic factors. To better understand this issue, we conducted a study to analyze the clinical features of neonatal jaundice and investigate UDP-glucuronosyltransferase 1A1 (UGT1A1) gene mutations among Tibetan newborns living in the Tibetan Plateau Region of China.Methods We collected umbilical cord blood samples, birth records, and maternal clinical data from healthy full-term Tibetan newborns born at Shannan Maternal and Child Health Hospital (3,000–4,000 m altitude). As a comparison group, Han newborns (the predominant ethnic group in China) born and residing in low-altitude regions were also included. UGT1A1 polymorphisms were analyzed by PCR and sequencing.Results A total of 121 Tibetan and 80 Han newborns were included. Among Tibetan newborns, Higher maternal red blood cell (RBC) counts, white blood cell (WBC) counts, and lower mid-pregnancy glucose levels were associated with neonatal jaundice. Meanwhile, compared to Han newborns, Tibetan newborns exhibited lower transcutaneous bilirubin (TcB) levels on postnatal days 2 and 3(P < 0.01), but no differences were observed on days 1, 4, or 5. Also, mothers of Tibetan newborns had higher blood pressure and liver/kidney function markers but lower MCV, WBC, NLR, and PLT (P < 0.05) as compared with Han neonates. Furthermore, Homozygous UGT1A1 c.211G > A mutations were associated with increased jaundice risk in both groups, while the frequency of -c.-3279T > G mutation was lower in our studied Tibetan newborns (P = 0.023).Conclusion Tibetan neonates with UGT1A1 c.211G > A mutation or whose mothers have high RBC and WBC and low glucose levels may have a higher jaundice risk. The lower frequency of the c.-3279T > G mutation in Tibetans may indicate a genetic adaptation to high altitude, potentially reducing jaundice susceptibility.