Molecular and phenotypic characteristics of patients with phenylketonuria in Serbia and Montenegro.

Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism in Caucasians. PKU is caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) enzyme. Here, we report the spectrum and the frequency of mutations in the PAH gene and discuss genotype-phenotype correlation in 34 unrelated patients with PKU from Serbia and Montenegro. Using both polymerase chain reaction-restriction fragment length polymorphism and 'broad-range' denaturing-gradient gel electrophoresis/DNA sequencing analysis, 19 disease-causing mutations were identified, corresponding to mutation detection rate of 97%. The most frequent ones were L48S (21%), R408W (18%), P281L (9%), E390G (7%) and R261Q (6%), accounting for 60% of all mutant alleles. The genotype-phenotype correlation was studied in homozygous and functionally hemizygous patients. We found that the most frequent mutation, L48S, was exclusively associated with the classical (severe) PKU phenotype. The mutation E390G gave rise to mild PKU. For the mutation R261Q, patients had been recorded in two phenotype categories. Considering allele frequencies, PKU in Serbia and Montenegro is heterogeneous, reflecting numerous migrations over the Balkan Peninsula.

Molecular basis of thalassemia syndromes in Serbia and Montenegro.

This study reports the molecular characterization of thalassemia syndromes in Serbian and Montenegrin populations. We identified eight beta-thalassemia mutations [codon 39 (C-->T), IVS-I-110 (G-->A), IVS-II-745 (C-->G), codon 44 (-C), -87 (C-->G), IVS-II-1 (G-->A), IVS-I-6 (T-->C), IVS I-1 (G-->A)] in 70 members of 29 families using polymerase chain reaction, reverse dot blot, amplification refractory mutation system and direct sequencing analysis. Hemoglobin (Hb) Lepore was found to be the most common cause of the thalassemia phenotype. Hb Sabine and alpha-thalassemia were detected as well. We also studied beta-globin gene cluster haplotypes and their association with the most common mutations. A novel haplotype associated with the Hb Lepore gene was identified. The results presented herein allowed the implementation of a prenatal diagnosis program in Serbia and Montenegro.

[Molecular characteristics of the thalassemia syndrome and prenatal diagnosis in a high risk family]. / Molekularna osnova sindroma talasemije i dijagnostika kod deteta pre rodjenja u porodici s visokim rizikom.

The diagnosis of thalassaemia maior has been established in a 6 months old infant by screenig tests. The sick child and his parents were included in the study. Reverse dote blot and allelle-specific PCR confirmed that the mother was heterozygous for mutation in the first intone of beta-globin chain at position 110-beta-IVSI-110. By gap-PCR it was established that the father was heterozygous for haemoglobinopathy Lepore. The child was double heterozygous for both mutations. During the next pregnancy, in the 11th week, faetal DNA was extracted from chorion villous. Fetus was heterozygous for haemoglobinopathy Lepore and carried the same mutation as the father. The parents the accepted information that the second child will be a silent carrier of mutation.

[The influence of protein and phosphorous restricted diet supplemented with essential aminoacids (EAA) and their alpha-keto-analogues (KAA) on nutritional status of children with chronic renal failure (CRF)]. / Uticaj normoenergetske, neselekcione niskoproteinske dijete na stanje uhranjenosti dece s hronicnom insuficijencijom bubrega.

The purpose of the study was to establish the influence of protein restricted diet supplemented with EAA/KAA on nutritional status of children with CRF. Seven childredn (four girls and three boys), aged from 7 years and eight months to 14 years and two months, with glomerular filtration rate of 42.6-9.2 ml/min/1.73 m2 and proteinuria of 0.025-1.125 g/24 h, who were on conservative treatment and who lived at home, were observed for six months. In prescribing energy value and protein intake WHO recommendations were used for healthly children (age for height). Through food 80-90% of energy and 80-85% of protein needs were provided. The remaining energy and proteins were provided by glucodextrin and EAA/KAA supplements respectevely. Average daily phosphorous intake amounted to about 550-800 mg. The obtained results showed that stunting and kwashiorkor like aminoacid disbalance were the prominent nutritional problems. This dietary regimen had a beneficial effect on all studied parameters. especially on height standard deviation score which increased from 1.71 +/- 2.6 to 1.5 +/- 4.3 (t = 2.809, p < 0.05); total essential/nonessential aminoacid score increased from 0.38 +/- 0.2 to 0.56 +/- 0.2 (t = 2.763, p < 0.05). The ratio between plasma concentration of four nonessential (glycine+serinet glutamine+taurine) to four essential (leucine+isoleucine+valine+methionine) amino acids decreased from 3.82 +/- 1.2 to 2.7 +/- 0.4 (t = 2.528, p < 0.05). Lymphocyte count increased from 1.809 x 10(9) +/- 0.268 x 10(9)/l to 2.314 x 10(9) +/- 0.922 x 10(9)/l (t = 2.431, p < 0.05). No significant changes were found in the values of relative body weight, arm circumpherence, triceps skinfold thickness, total plasma protein, albumin, transferine, complement C3 and plasma valin/glycin and phenylalanine/thyrosine ratio. It should be noted that the significant changes were not found in the results of these latter anthropometric biochemical parameters in relation to their primary almost insignificant values.