Variants of organic anion transporter polypeptide 2 gene are not risk factors associated with severe neonatal hyperbilirubinemia.
OBJECTIVE
This study aimed to determine the prevalence of four variants of organic anion transporter polypeptide 2 (OATP2) gene, and their association with severe hyperbilirubinemia.


METHODS
Observational study.


METHODS
A tertiary university unit.


METHODS
Term infants of Chinese descent.


METHODS
175 infants, consisting of 65 admitted for treatment of severe hyperbilirubinemia (with serum bilirubin levels > 250 mmol/L at age 1-2 days or > 300 micromol/L at age > or = 3 days) and 110 randomly selected inborn infants without severe hyperbilirubinemia during their first month of life, were recruited. Their blood samples were subjected to sequencing analysis of exon 4 and exon 5 of OATP2 gene for detection of c.388A > G, c.521T > C, c.571T > C and c.597C > T variants.


RESULTS
The c.388A > G variant was the most common, and the c.521 T > C was least common, being present in 90.9% and 26.9% of the infants, respectively. Forward logistic regression analysis showed that the only significant risk factors associated with severe hyperbilirubinemia among these Chinese infants were: exclusive breast feeding (adjusted odds ratio (OR) = 12.5, 95% C.I.: 2.9, 53.4; p = 0.001), infants with homozygous 211 variant of the UDPG 1A1 gene (adjusted OR = 37.7, 95% C.I.: 4.4, 324.1; p = 0.001), and G6PD enzyme level < 8.5 IU/g Hb (adjusted OR = 7.3, 95% C.I.: 3.1, 17.5; p < 0.00001). Gestational age, G6PD mutation status, actual G6PD enzyme level, and the 4 variants of the OATP2 gene mutation were not significant risk factors.


CONCLUSIONS
Variants of OATP2 gene were not significant risk factors associated with severe hyperbilirubinemia in Malaysian Chinese infants.
Unit of Haematology, Department of Diagnostic Laboratory Services, Universiti Kebangsaan Malaysia Medical Center, Kuala Lumpur, Malaysia.
Fei-Liang
FL
Wong
Nem-Yun
NY
Boo
Othman
O
Ainoon
May-Kay
MK
Wang
D001724:Birth Weight; D004252:DNA Mutational Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005865:Gestational Age; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000235:genetics* / Q000378:metabolism; D007231:Infant, Newborn; D027381:Liver-Specific Organic Anion Transporter 1 / Q000235:genetics*; D008297:Male; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors
D027381:Liver-Specific Organic Anion Transporter 1