Objectives: This study aimed to determine the prevalence of four variants of organic anion transporter polypeptide 2 (OATP2) gene, and their association with severe hyperbilirubinemia. Design: Observational study. Setting: A tertiary university unit. Patients: 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 μmol/L at age ≥ 3 days) and 110 randomly selected inborn infants without severe hyperbilirubinemia during their fi rst 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 signifi cant 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 signifi cant risk factors. Conclusion: Variants of OATP2 gene were not signifi cant risk factors associated with severe hyperbilirubinemia in Malaysian Chinese infants.

OBJECTIVETo determine the prevalence of a common GJB2 mutation in a big Chinese population of deaf children and the features of its distribution in regions all over the nation and to provide epidemiology data and expertise for genetic testing of deafness in China.

METHODSThe DNA samples of NSHI patients and normal controls were collected from different typical areas of China. The method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with ApaI was used to determine the genotype of GJB2 235 site.

RESULTSTotally 16.3% of patients carried at least one 235 delC mutant allele. Among them, 7.8% was homozygous and 8.5% was heterozygous. The prevalence of GJB2 235delC mutation in China was evident, and the significant difference of 235delC mutation frequency was found in sub-population from different areas and different ethnic groups.

CONCLUSIONSBased upon the result of this screening as stated, Chinese NSHI patients appear to have 235delC frequency and the number of GJB2 related deafness was estimated to be huge. The testing of GJB2 235delC mutation would play an important role in genetic diagnosis and screening in China. As high as 15% of patients could be diagnosed as GJB2 caused deafness (bi-allelic mutation) only by means of this simple, fast and economic assay. In addition, patients were negative for 235delC mutation would be candidates for further mutational analysis of GJB2 or other deafness related genes.

Adolescent ; Adult ; Alleles ; Asian Continental Ancestry Group ; genetics ; Child ; Child, Preschool ; China ; epidemiology ; Connexin 26 ; Connexins ; genetics ; Female ; Genotype ; Hearing Loss, Sensorineural ; epidemiology ; genetics ; Heterozygote ; Homozygote ; Humans ; Male ; Point Mutation ; Prevalence ; Young Adult