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Biomedical subjects

L Vilarinho

Publications and source records attributed to L Vilarinho.

49 records · Page 3Linked to original sources
PubMed1995

A mild form of infantile isolated sulphite oxidase deficiency.

Neonatal sulphite oxidase deficiency is characterised by severe neurologic dysfunction, brain atrophy, dislocation of the lens and increased urinary excretion of sulphite, thiosulphate, taurine and S-sulphocysteine, and by a low plasma cystine. We present clinical, neuroradiological and biochemical data of a patient with late onset symptoms comparing this presentation with the neonatal form and stressing the difficulties of the diagnosis of this disorder.

Atrophy↗
PubMed1992

Linkage disequilibrium between phenylketonuria and RFLP haplotype 1 at the phenylalanine hydroxylase locus in Portugal.

RFLPs of 36 normal and 41 mutant alleles at the phenylalanine hydroxylase locus were determined in 31 Portuguese kindreds. A total of 14 haplotypes including 10 normal and 7 mutant alleles were observed. Almost 75% of all mutant alleles were confined within only two haplotypes, namely haplotype 9 (17.1%) and haplotype 1 (56.1%). This frequency of mutant haplotype 1 in Portugal is, to our knowledge, the highest for this mutant haplotype in all studies reported to date. Other mutant haplotypes were either rare (haplotype 2, 9.7%) or totally absent (haplotype 3, 0%). Only 24.5% of all mutant alleles were found to consistently carry identified mutations, particularly R261Q (9.8%), R252W (3.3%), R408W (1.6%) and delta I94 (3.3%). A new mutation, L249F, located in the seventh exon of the gene, accounted for 6.5% of all mutant alleles in our series. Interestingly, this mutant genotype was consistently associated with mutant haplotype 1 (P less than 0.01), as also observed for the R261Q mutation. It appears, therefore, that mutant haplotype 1 is genotypically heterogeneous in Portugal and that more than two mutations account for its prevalence in this country.

Alleles↗
PubMed1992

[National screening for phenylketonuria, congenital hypothyroidism and congenital adrenal hyperplasia].

In Portugal the screening for phenylketonuria (PKU) and congenital hypothyroidism (CH) was begun towards the end of 1979, and by 1990 59 cases of PKU and 227 cases of CH had been detected. The early initiation of treatment and the observed mental and motor development, point towards a normal development in these children. A trial screen for congenital adrenal hyperplasia was carried out in 100.000 newborns, from which it was concluded that, under the present conditions, screening at a national level is not justified. A similar study is currently being undertaken for biotinidase deficiency and cystic fibrosis. The results ares discussed, as are the cost/benefits evaluations.

Adrenal Hyperplasia, Congenital↗
PubMed1991

A 3-base pair in-frame deletion of the phenylalanine hydroxylase gene results in a kinetic variant of phenylketonuria.

Phenylketonuria (PKU) is an autosomal recessive disease due to deficiency of a hepatic enzyme, phenylalanine hydroxylase (PAH). The absence of PAH activity results in typical PKU while persistence of a residual enzyme activity gives rise to variant forms of the disease. We report here a 3-base pair in-frame deletion of the PAH gene (delta 194) in a mild variant, with markedly reduced affinity of the enzyme for phenylalanine (Km = 160 nM), and we provide functional evidence for responsibility of the deletion in the mutant phenotype. Since the deletion was located in the third exon of the gene, which presents no homology with other hydroxylases, we suggest that exon 3 is involved in the specificity of the enzyme for phenylalanine. Finally, since none of the 98 PKU patients tested were found to carry this particular deletion, our study suggests that this molecular event probably occurred recently on the background of a haplotype 2 gene in Portugal.

Base Composition↗