Evaluation of the clinical value of the newly identified urine biomarker HIST1H4K for diagnosis and prognosis of prostate cancer in Bulgarian patients.

PURPOSE: Searching for diagnostic and prognostic biomarkers for prostate cancer (PC) is main public health priority. DNA methylation in body fluids is a stable, easily detectable and promising PC biomarker. The major advantages of urine-based assays are their noninvasive nature and the ability to monitor PC with heterogeneous foci. The aim of this study was to determine the diagnostic value of the recently identified candidate PC biomarker HIST1H4K. METHODS: We investigated DNA methylation of HIST1H4K in urine samples from 57 PC patients, 29 controls with benign prostatic hyperplasia (BPH) and 50 young asymptomatic men (YAM) by MethyLight real-time PCR. RESULTS: The frequency of HIST1H4K promoter hypermethylation significantly discriminated PC patients from YAM (AUC =0.763; 95% CI 0.672-0.839; p<0.0001), but did not show any statistical difference between PC patients and BPH controls (AUC=0.513, 95% CI 0.402-0.622; p=0.8255). HIST1H4K could not outperform the prostatic specific antigen (PSA) in our sample (AUC=0.785; 95% CI 0.679-0.870; p<0.0001). Methylation of HIST1H4K showed significant correlation with aging (r=0.5418; p<0.0001), but with no other clinicopathological characteristics. CONCLUSION: The results suggest that the promoter hypermethylation of HIST1H4K is rather due to aging than related to prostate carcinogenesis. To elucidate this observation analysis of larger samples is needed.

Mutation spectrum in the nephrin gene (NPHS1) in congenital nephrotic syndrome.

Congenital nephrotic syndrome, Finnish type (CNF or NPHS1), is an autosomal recessive disease characterized by massive proteinuria and development of nephrotic syndrome shortly after birth. The disease is most common in Finland, but many patients have been identified in other populations. The disease is caused by mutations in the gene for nephrin which is a key component of the glomerual ultrafilter, the podocyte slit diaphragm. A total of 30 mutations have been reported in the nephrin gene in patients with congenital nephrotic syndrome worldwide. In the Finnish population, two main mutations have been found. These two nonsense mutations account for over 94% of all mutations in Finland. Most mutations found in non-Finnish patients are missense mutations, but they include also nonsense and splice site mutations, as well as deletions and insertions. This mutation update summarizes the nature of all previously reported nephrin mutations and, additionally, describes 20 novel mutations recently identified in our laboratory.

C283Y mutation and other C-terminal nucleotide changes in the gamma-sarcoglycan gene in the Bulgarian Gypsy population.

Sarcoglycanopathies, affecting the dystrophin-associated sarcoglycan (SG) complex, are a heterogeneous group of neuromuscular disorders. A subgroup of these disorders, limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive disorder, clinically manifested as an early onset, severe Duchenne-like muscular dystrophy. LGMD2C is caused by mutations in the gamma-SG gene, localized on 13q12. Recently, a number of mutations have been described in that gene, among which C283Y, a "private" Gypsy mutation (eight codons before the 3' end of the gene) is detected. In this article, we report on a single-strand conformation polymorphism (SSCP) method for fast C283Y mutation detection, using direct dry blood spot amplification. The method permits a large number of samples to be easily screened. To check heterozygote carriers of C283Y mutation among Gypsy population in Bulgaria, the SSCP analysis was applied on 400 Gypsy newborns from northeast Bulgaria. Our results show 2.25% of heterozygosity, which means that 1 in 50 Gypsies carries the mutation. Moreover, new SSCP migration patterns were detected that revealed two polymorphisms still unavailable in the literature. One of these changes was 984G-->A, leading to substitution of conserved serine at position 287 with asparagine and the second one is 1049C-->G at the 3' UTR (untranslated region). The present data could help the understanding the role of these sequences for the protein function.