Identification of a single base insertion in the COL4A5 gene in Alport syndrome

Identification of a single base insertion in the COL4A5 gene in Alport syndrome. We identified a novel mutation in the COL4A5 gene of a Japanese patient with Alport syndrome. A combination of in vitro amplification of the exons with single strand conformation polymorphisms (SSCP) analysis suggested the presence of a mutation in exon 48. Sequencing of the amplified DNA revealed a single base (T) insertion which was between nucleotides T 4750 and G 4751 within the methionine 1516. This mutation caused a shift in the reading frame of nine amino acids and introduced a premature termination signal that would be expected to lack about two-thirds of the noncollagenous (NCI) domain. This mutation may interfere with type IV collagen assembly leading to increased permeability and play a causative role in the glomerular basement membrane abnormality of this patient with typical Alport syndrome. Gene tracking by restriction enzyme NlaIII digestion revealed that the patient's mother is heterozygous whereas the patient's brother and one sister are normal, albeit they have hematuria and proteinuria. Without gene analysis, they would have been misdiagnosed. We propose that the diagnosis of Alport syndrome should be made on the basis of both clinical phenotypes and molecular defects

Mutations in the COL4A5 gene in Alport syndrome: A possible mutation in primordial germ cells

Mutations in the COL4A5 gene in Alport syndrome: A possible mutation in primordial germ cells. Using a combination of gene amplification with single strand conformation polymorphisms analysis and sequencing, we examined the COL4A5 gene in 37 patients with Alport syndrome. In patient A8, a single base insertion was noted at codon 1,597 tyrosine in exon 49. The premature terminal signal appeared and 89 amino acids (approximately one-third) of the non-collagenous domain were lost. The mutation was present in the mother, hence she is heterozygous. In patient A12, the nucleotide changed from C to T at codon 1,679 glutamine in exon 51, which created a termination codon, and 7 amino acids at the carboxyl terminus were lost. Gene tracking using peripheral leukocytes revealed that the parents did not carry the mutant allele, while the sister was heterozygous. DNA samples from hair roots and skin fibroblasts of the mother were normal and immunological examination of the epidermis of the mother indicated that the α5(IV) chain was normally expressed. As these results suggest that somatic cells of the mother do not carry the mutant allele, the primordial germ cells possibly carry a fresh mutation in the mother of patient A12

Tolerability, Efficacy, and Safety of Bisoprolol vs. Carvedilol in Japanese Patients With Heart Failure and Reduced Ejection Fraction - The CIBIS-J Trial -

Background: The comparative tolerability, efficacy, and safety of bisoprolol and carvedilol have not been established in Japanese patients with heart failure and reduced ejection fraction (HFrEF). Methods and Results: The CIBIS-J trial is a multicenter, open-label, non-inferiority randomized controlled trial of bisoprolol vs. carvedilol in 217 patients with HFrEF (EF <= 40%). The primary endpoint was tolerability, defined as reaching and maintaining the maximum maintenance dose (bisoprolol 5 mg/day or carvedilol 20 mg/day) during 48 weeks of treatment. The primary endpoint was achieved in 41.4% of patients in bisoprolol (n=111) and 42.5% in carvedilol (n=106) groups. The non-inferiority of tolerability of bisoprolol compared with carvedilol was not supported, however, neither beta-blocker was superior with regard to tolerability. Heart rate (HR) decreased in both groups and its decrease from baseline was significantly greater in the bisoprolol group (20.3 vs. 15.4 beats/min at 24 week, P<0.05). Plasma B-type natriuretic peptide (BNP) levels decreased in both groups and the decrease was significantly greater in the carvedilol group (12.4 vs. 39.0 % at 24 weeks, P<0.05). Conclusions: There were no significant differences between bisoprolol and carvedilol in the tolerability of target doses in Japanese HFrEF patients. The clinical efficacy and safety were also similar despite the greater reduction in HR by bisoprolol and plasma BNP by carvedilol