Quality of diagnostic mutation analyses for phenylketonuria.

DNA sequence analyses have become a major component in the diagnostic work-up of patients; however, limited consideration appears to be given to the possibility that reported results may in fact be wrong. Over the last four years we have carried out an External Quality Assessment scheme for mutation analysis in phenylketonuria. Each year, three DNA samples with previously characterized genotypes were mailed to participating laboratories.

BH4-sensitive hyperphenylalaninemia: new case and review of literature.

We report a patient with BH(4)-sensitive phenylketonuria. In neonatal screening, phenylalanine levels above 10 mg/dl were detected. In the tetrahydrobiopterin- (BH(4)) loading test, phenylalanine concentrations in serum fell significantly.

Mutational spectrum in German patients with phenylalanine hydroxylase deficiency.

We report on the spectrum and frequency of mutations in the phenylalanine hydroxylase (PAH) gene in 226 German families with PAH deficiency, most of them from Southern Germany. A total of 88 mutations were identified in 428 out of 438 mutant PAH alleles including one novel stop mutation L293X (c.878T>A).

Distinct spectrum of CFTR gene mutations in congenital absence of vas deferens.

Congenital absence of the vas deferens (CAVD) is a frequent cause for obstructive azoospermia and accounts for 1%-2% of male infertility. A high incidence of mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene has recently been reported in males with CAVD. We have investigated a cohort of 106 German patients with congenital bilateral or unilateral absence of the vas deferens for mutations in the coding region, flanking intron regions and promotor sequences of the CFTR gene.