We report a functioning ductus venosus with hypoplasia of the right hepatoportal system in a 2-year-old child born with asymmetric intra-uterine growth retardation. Postprandial galactosaemia and hyperammonaemia were clues to diagnosis of portal-systemic shunt through the patent ductus venosus, which was confirmed by ultrasonography and angiography.

Episodes of blood-streaked stools are not uncommon in exclusively breast-fed infants under 6 months of age. Such bleeding is thought to be associated with food protein-induced proctocolitis, however the pathomechanism remains unclear. The aim of this study was to investigate intestinal microbiota and secretory immunoglobulin A in the feces of exclusively breast-fed infants with blood-streaked stools. Fecal specimens from 15 full-term infants with blood-streaked stools and 15 breast-fed healthy infants were studied and the results compared. All infants had been delivered vaginally and exclusively breastfed. The fecal microbiota were investigated by phylogenetic analysis combined with culture methods for some bacterial species, and feces were assessed for the presence of fecal secretory immunoglobulin A by enzyme-linked immunosorbent assay. Phylogenetic cluster analysis revealed four major clusters of fecal bacteria, cluster A being found only in healthy infants. The Bacteroides fragilis group was observed more frequently in controls than in patients (P < 0.05). In the controls, the predominant species belonging to the Enterobacteriaceae group was Escherichia coli, whereas in the patients it was Klebsiella (P < 0.05). Concentrations of secretory immunoglobulin A were high in one third of the healthy controls. In conclusion, the pathomechanism of rectal bleeding in exclusively breast-fed infants may be related to differences in the composition of their intestinal flora.Key words food protein-induced proctocolitis, hygiene hypothesis, phylogenetic analysis, rectal bleeding.In developed countries, blood-streaked stools are not uncommon in exclusively breast-fed infants with favorable weight gain (1-3). This phenomenon has been attributed to food protein-induced proctocolitis, the proposed mechanism involving hypersensitivity to allergens present in breast milk: it is thus regarded as a form of food allergy. Even when breast-feeding is continued, the rectal bleeding

Two distinct human light subunits of the heteromeric amino acid transporter, y+LAT-1 coded by SLC7A7 and y+LAT-2 coded by SLC7A6, are both known to induce transport system y+L activity. SLC7A7 has already been identified as the gene responsible for lysinuric protein intolerance (LPI). We successfully identified five novel SLC7A7 variants (S238F, S489P, 1630delC, 1673delG, and IVS3-IVS5del9.7kb) in Japanese patients with LPI by PCR amplification and direct DNA sequencing. In addition, we performed a semi-quantitative expression analysis of SLC7A7 and SLC7A6 in human tissue. In normal tissue, the gene-expression ratio of SLC7A6 to SLC7A7 was high in the brain, muscle, and cultured skin fibroblasts; low in the kidneys and small intestine; and at an intermediate level in peripheral blood leukocytes, the lungs, and cultured lymphoblasts. The gene-expression ratio of SLC7A6 to SLC7A7 in cultured lymphoblasts was significantly different between normal subjects and LPI patients with R410X and/or S238F, where the relative amount of SLC7A7 mRNA was significantly lower and the relative amount of SLC7A6 mRNA was statistically higher in affected lymphoblasts than in normal cells. Expression of SLC7A7 and SLC7A6 may thus be interrelated in cultured lymphoblasts.

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Lysinuric protein intolerance is an autosomal recessive disease characterized by defective transport of the dibasic aminoacids. Mutational analysis of LPI patients in the northern part of Japan revealed that six were homozygous for the R410X mutation and two others were compound heterozygotes of R410X and other unknown mutations. In the population epidemiology study in a local cluster in the northern part of Iwate, ten heterozygotes were found in 1190 newborn babies leading to an estimated LPI incidence of 1/57,000. Polymorphism analysis revealed two major alleles, A and B, in intron 8. While the population frequency of allele A was 0.9 and that of allele B was 0.1 in the northern part of Japan the R410X mutations were exclusively on allele B in 31 chromosomes suggesting a founder effect. Genetic analysis in patients revealed strong linkage disequilibrium with D14S283 and TCRA indicating that the R410X mutation occurred before at least 130 generations ago (about 2600 years). The R410X mutation was shown to be useful as a molecular marker for screening LPI patients in the northern part of Japan. Hum Mutat 16:270–271, 2000. © 2000 Wiley‐Liss, Inc.