No abstract

No abstract

ABSTRACT:The uridine diphosphoglucuronate-glucuronosyltransferase 1A1 (UGT1A1) gene encodes the enzyme responsible for bilirubin glucuronidation. To evaluate the contribution of UGT1A1 promoter mutations to neonatal jaundice, we determined the genotypes of c.-3279TϾG, c.-3156GϾA, and A(TA)7TAA in Malay infants with neonatal jaundice (patients) and in infants without neonatal jaundice (controls). In our population study, only c.-3279TϾG was associated with neonatal jaundice. The genotype distributions between both groups were significantly different (p ϭ 0.003): the frequency of homozygosity for c.-3279G was much higher in patients than those in controls. Allele frequency of c.-3279G was significantly higher in patients than those in controls (p ϭ 0.006). We then investigated changes in transcriptional activity because of c.-3279TϾG. Luciferase reporter assay in HepG2 cells demonstrated that transcriptional activity of the c.-3279G allele was significantly lower than that of the c.-3279T allele in both the absence and presence of bilirubin. Luciferase reporter assay in COS-7 cells elucidated that c.-3279TϾG modified the synergistic effects of the nuclear factors associated with transcriptional machinery. In conclusion, the c.-3279TϾG mutation in the UGT1A1 promoter is a genetic risk factor for neonatal jaundice. T he uridine diphospho (UDP)-glucuronate-glucuronosyltransferase 1A1 (UGT1A1) gene encodes bilirubin UDPglucuronosyltransferase (UGT1A1), which is the enzyme responsible for bilirubin glucuronidation. A decrease in UGT1A1 activity leads to unconjugated hyperbilirubinemia. Inherited UGT1A1 deficiencies because of UGT1A1 mutations are classified into three forms based on clinical severity: Crigler-Najjar syndrome type 1 (CN-1, a severe form), Crigler-Najjar syndrome type 2 (CN-2, an intermediate form), and Gilbert's syndrome (GS, a mild form) (1,2). Such inherited UGT1A1 deficiencies may cause neonatal jaundice.A mutant TATA box with an additional TA insertion, A(TA)7TAA, was first found in patients with CN-1, CN-2, and GS (3-5). GS with homozygosity for A(TA)7TAA accelerates or prolongs neonatal jaundice (6). This mutation is frequently observed in whites and Africans (7). Another GScausing gene mutation, c.211GϾA, is frequent in the East Asian population (8). The c.211GϾA mutation causes an amino acid change, glycine to arginine at codon 71.Recently, polymorphic mutations, c.-3279TϾG and c.-3156GϾA, were identified in the UGT1A1 promoter region (9,10). The c.-3279TϾG mutation is located in the phenobarbital responsive enhancer module (gtPBREM), which is activated by a nuclear receptor, constitutive androstane receptor (CAR) (11). Sugatani et al. (9) showed using luciferase reporter assay that mutant gtPBREM with c.-3279TϾG decreases the transcriptional activity of the UGT1A1 promoter by 60%. The c.-3156GϾA mutation is located between the gtPBREM and TATA box. A haplotype analysis showed that there is a high extent of linkage disequilibrium between c.-3156GϾA and A(TA)7TAA (10,12). However, it is unknown ...

Diagnostic physical interventions in the patient confirmed the phenotype presentation consistent with PMC, and the in silico protein modeling analysis of p.Arg1448His predicted structural changes which can affect function of the protein. All the data confirmed the diagnosis of PMC in the patient and added to existing literature emphasizing the important role of arginine residue at 1448.

The SMA-diagnosing system, combined with the mailing of DBS on filter paper, will be beneficial for patients suffering from neuromuscular disorders in areas with limited or no access to diagnostic facilities with molecular capabilities.

Licorice ingestion, as well as mutations in the HSD11B2 gene, inhibits 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) enzyme activity, causing the syndrome of apparent mineral corticoid excess (AME). However, the combined effect of licorice ingestion and an HSD11B2 mutation has never been reported, until now. In this study, we demonstrated that licorice ingestion can produce overt hypertension in an individual without medical history of hypertension who is heterozygous for wild-type and mutant HSD11B2 genes. Our patient was a 51-year-old female with serious hypertension who had been taking herbal medicine containing licorice for more than one year. She was clinically diagnosed as having licorice intoxication, because she did not present with hypertension after ceasing the herbal medicine. Molecular analysis showed that she carried a missense mutation, c.40C>T, in HSD11B2. In conclusion, licorice ingestion is an environmental risk factor for hypertension or AME state in patients with a mutation in HSD11B2. Carrying a mutation in HSD11B2 is, conversely, a genetic risk factor for licorice-induced hypertension or AME state. Herbal medicine containing licorice may, therefore, be contraindicated in patients with an HSD11B2 mutation.

The patient was an 8-year-old Japanese girl with Gilbert's syndrome (GS). Based on the DNA analysis, she was homozygous for a T-to-G transversion at nucleotide position 1456 in the UGT1A1 gene, leading to the substitution of aspartate for tyrosine at position 486 of the UGT1A1 enzyme. Because this mutation is located in an exon common to UGT1A genes, all the UGT1A enzymes may be affected. It is well-known that UGT1A1, UGT1A6 and UGT1A9 enzymes glucuronidate acetaminophen. To evaluate acetaminophen tolerance in the patient, serum acetaminophen levels were determined after oral administration of acetaminophen (15 mg/kg). The maximum serum acetaminophen level reached (12.8 µg/mL) was far below the toxic level. The finding suggested that the usual therapeutic dose of acetaminophen is safe for the GS patient. The combination of mutation analysis in UGT1A1 and acetaminophen loading test may be useful to avoid adverse effect in GS patients.

HRMA is a simple but versatile tool to add to the existing arsenal of diagnostic techniques that could aid clinicians/researchers in diagnosing SMA. However, as we demonstrate in the present study, the design and selection of primers is of monumental importance in ensuring the successful application of HRMA to screening for pathogenic variants.