Klaus M. Keller

Frequent 4-bp deletion in exon 9 of the SMAD4/MADH4 gene in familial juvenile polyposis patients

Familial juvenile polyposis (FJP) is a hamartomatous polyposis syndrome characterized by the appearance of juvenile polyps in the gastrointestinal tract. Patients with this syndrome are at an increased risk for cancer of the colon, stomach, and pancreas. Recently, germline mutations in the SMAD4/DPC4 gene (official symbol MADH4) have been found in the majority of patients suffering from FJP. We have examined 11 unrelated patients with FJP for MADH4 germline mutations by direct sequencing of genomic DNA encompassing all 11 exons of the gene. Besides a novel mutation (959–960delAC at codon 277, exon 6) in one patient, we observed a 4‐bp deletion (1372–1375delACAG) in exon 9 in two unrelated patients. Examination with microsatellite markers flanking MADH4 supports an independent origin of the mutation in these two families. The same 4‐bp deletion in exon 9 has previously been described in three out of nine patients examined for MADH4 mutations. Our results combined with these previous data demonstrate that a unique 4‐bp deletion in exon 9 of MADH4 accounts for about 25% of all FJP cases and that other MADH4 mutations occur in an additional 15% of patients. Genes Chromosomes Cancer 25:403–406, 1999.

Dual versus triple therapy of Helicobacter pylori infection: results of a multicentre trial

OBJECTIVE To compare dual therapy (omeprazole and amoxicillin) with triple therapy (omeprazole, amoxicillin, and clarithromycin) in the treatment ofHelicobacter pylori infection. The efficacy of 1 mg/kg/day omeprazole was randomly compared with 2 mg/kg/day. STUDY DESIGN 252 patients (median age, 11.0 years; range, 3–18) presenting with chronic abdominal pain underwent endoscopy and a 13C-urea breath test. Gastric biopsy specimens were taken for histological examination and for the rapid urease test. Patients were treated for two weeks: group A (n = 63) received amoxicillin (50 mg/kg; maximum, 2 g/day), group B (n = 73) received amoxicillin and clarithromycin (20 mg/kg; maximum, 1 g/day). Both groups were randomly treated with either 1 or 2 mg/kg omeprazole (maximum, 80 mg/day). Diagnostic procedures were repeated four weeks after the end of treatment. RESULTS 11 patients were excluded; 136 patients were H pyloripositive (56%), 105 of whom were re-examined after treatment.Helicobacter pylori was eradicated in 52% of group A and 83% of group B. The dose of omeprazole had no influence on the eradication rate. Specificity and sensitivity of the rapid urease test were 94% and 93%, respectively. Specificity and sensitivity of the 13C-urea breath test were 93% and 95%, respectively. CONCLUSIONS Dual therapy can no longer be recommended. Triple therapy is more effective than dual therapy in the eradication of H pylori infection. The lower dose of 1 mg/kg omeprazole was as effective as 2 mg/kg.

A new mutation of the glucose-6-phosphatase gene in a 4-year-old girl with oligosymptomatic glycogen storage disease type 1a

A 4-year-old German girl was diagnosed as having glycogen storage disease type la and showed no other marked symptoms except hepatomegaly. The glucose-6-phosphatase activity in the liver was approximately 1.5% to 5.0% of normal values, and molecular analysis revealed compound heterozygosity for R83C and the novel mutation N264K. This result indicates that there is a wide clinical variation of glucose-6-phosphatase deficiency. DNA analysis is helpful for confirmation of the diagnosis, as well as establishment of the genotype and phenotype correlation in glycogen storage disease type 1a.

The diagnostic significance of IgG cow's milk protein antibodies re-evaluated.

The effect of different feeding regimens, notably the use of hydrolysed cows milk formulas, on the development of allergic reactions and the development of cows milk protein-IgG antibodies is still disputed. We prospectively compared the development of allergic manifestations and cows milk protein-IgG antibodies in a total of 702 infants who were divided into six groups:1.exclusively breast milk for at least 4 weeks (n=206).2.Breast milk plus initial partially hydrolysed formula (n=104).3.Breast milk plus extensively hydrolysed formula (n=50).4.Breast milk plus initial conventional cows milk formula (n=73).5.Conventional cows milk with or without breast milk throughout (n=187).6.Extensively hydrolysed cows milk formula for 2 months, followed by conventional cows milk (n=82).Cows milk protein antibodies were determined by an indirect immuno-fluorescent test. Antibody titres rose slowly in groups 1, 3 and 6. Children in group 5 showed two high peaks. There were no significant differences in the frequency and type of allergic manifestations between the groups. Introduction of cows milk formula during the first trimenon resulted in elevated antibody titres in all breast fed infants compared with introduction at a later date. Conclusion: In contrast to a previous study from the same laboratory, there is no diagnostic significance of cows milk protein-IgG antibodies for allergic manifestations. The occurrence of these antibodies is a physiological phenomenon: the shorter the breast feeding period and the earlier cows milk formula is introduced, the higher the antibody levels.

Persistent Hepatitis G Virus Infection After Neonatal Transfusion

BACKGROUND Recently two Flaviviridae-like viruses have been discovered and named GB virus C and hepatitis G virus. Molecular characterization showed them to be different subtypes of the same virus. An association with posttransfusion hepatitis and with sporadic and fulminant hepatitis was reported, but most infected people remain asymptomatic. Data concerning hepatitis G virus infection in infants and children have not been reported to date. The prevalence of hepatitis G virus infection in children after transfusion of blood products in the neonatal period was studied. METHODS Serum samples from 251 children, who had received blood products in the first 4 weeks of life and who had been reexamined as part of another study at a mean interval of 37 months (range, 10-70) after last transfusion, were analyzed for hepatitis G virus infection. Follow-up examinations were performed in 14 of 19 hepatitis G virus-positive children 12 to 17 years after the last transfusion. Presence of hepatitis G virus RNA in serum was determined by a reverse transcription polymerase chain reaction assay with nested primers from the helicase region of the hepatitis G virus. To prove specificity of the hepatitis G virus, reverse transcription polymerase chain reaction assay and compare follow-ups with initial sequences, direct sequencing of the NS3 and NS5 regions of the hepatitis G virus was performed. RESULTS Hepatitis G virus RNA was detected in 19 of 251 patients (7.6%); sequence analysis showed the isolates to be of hepatitis G virus type. None of the patients with hepatitis G virus infection had evidence of liver disease, although 3 patients were coinfected with hepatitis C virus. Four of 14 patients who were reinvestigated after a mean of 15 years showed persistent hepatitis G virus infection. Each of the 4 children was healthy. In none were clinical signs of liver disease observed; liver function test results were within the normal range. CONCLUSIONS Children receiving blood transfusions in the neonatal period are at increased risk of hepatitis G virus infection with a high rate of chronic infection. However, as in the findings in several studies of adult transfusion recipients, in the current results, no association between hepatitis G virus infection and clinical or biochemical signs of hepatitis or extrahepatic disease could be seen.

Differences in the clinical and radiologic patterns of rotavirus and non-rotavirus necrotizing enterocolitis

We analyzed retrospectively 32 successive infants who developed necrotizing enterocolitis (NEC), 13 with rotavirus (RV) infection (RV+) and 19 RV-negative (RV-). All patients showed at least pneumatosis intestinalis. All patients except one had risk factors for perinatal asphyxia. Our study demonstrated significant differences between RV+ NEC and RV- NEC cases: RV+ NEC infants had a higher birth weight and were born at a later gestational age. Oral feeding was started earlier and symptoms developed later and more insidiously in RV+ patients than in RV- NEC babies. Radiology revealed a less severe and more distal colon involvement in RV+ NEC infants, whereas the RV- NEC patients mostly had small intestinal or ileocecal changes and more frequent complications of pneumoportogram and intestinal perforations. These latter infants often had a rapidly deteriorating clinical course; 84% needed surgical treatment. In conclusion RV may be a cause of NEC in susceptible infants. Historic and clinical data and a more distal colonic pneumatosis allow a differentiation of RV+ NEC from other forms of NEC.

IgG, IgA, and IgE antibodies to cow milk proteins in an allergy prevention study.

In the last few years, several trials have been carried out to determine if certain feeding regimens in neonates prevent atopic diseases1–13. In our country, there is a continuing debate about nutritional supplementation of breast milk with hydrolysate formulas: in the first days of life should only newborns at allergy risk8,9,11,14, or should all newborns be fed only breast milk? This age is claimed to be an especially vulnerable period for a sensitization against foreign proteins because of intestinal immaturity and inexperienced gut-associated lymphoid tissue15. A prospective Danish study revealed cases of cow’s milk allergy only among those breastfed infants who had received cow’s milk formula as a “night-bottle”16. Others reported allergic manifestations in infants after a sensitization by small quantities of antigens via human milk17,18. The milk industries have provided pediatricians with several new “hypoallergenic” (HA) hydrolysate formulas of different origin and of different molecular size promising allergy prevention not only in newborns at risk.

Peutz-Jeghers syndrome: four novel inactivating germline mutations in the STK11 gene. Mutations in brief no. 227. Online.

In order to obtain a survey of the mutations being prevalent in Northern Germany and to enable molecular genetic testing for families with clinically diagnosed familial hypercholesterolemia (FH), we screened 46 unrelated German individuals with elevated LDL levels for mutations in the 18 exons and their flanking intron sequences including the promotor region of the LDL receptor (LDLR) gene. In addition, we tested all patients for the presence of mutations in the gene coding for apolipoprotein B-100 (apoB-100). We detected 15 mutations affecting the LDLR gene, 8 of which, designated A29S, 195insAT, 313+1insG, 553insG, 680insGGACAAATCTG, D200N, E267K and L411V have not yet been reported. One patient is heterozygous for the double mutant N543H and 2393del9Bp. Two patients carried the mutation R3500Q (Arg-->Glu) within the apoB-100 gene.The diagnosis of Peutz‐Jeghers syndrome is based on the occurrence of hamartomatous gastrointestinal polyps and perioral pigment spots. In view of the development of hamartomatous polyps in several syndromes and the variability of pigment spots in Peutz‐Jeghers patients, identification of affected individuals is difficult. Recently, germline mutations in the STK11 gene have been reported as a molecular cause of Peutz‐Jeghers syndrome. We present four novel inactivating mutations identified by direct sequencing of all 9 exons of the STK11 gene in 4 patients suggestive of Peutz‐Jeghers syndrome: three frameshift mutations (125‐137del; 474‐480del; 516‐517insT) and one nonsense mutation (Q220X). Our data obtained in these patients and in those reported previously emphasize the diagnostic value of histological discrimination between different types of hamartomatous polyps and of molecular analysis, particularly in cases with no family history of the disease.

GB virus C/hepatitis G virus infection in HIV infected patients with haemophilia despite treatment with virus inactivated clotting factor concentrates

AIM To determine the frequency of GB virus C (GBV-C)/hepatitis G virus (HGV) infection before and after switch to the use of virus inactivated concentrates in haemophiliac patients infected with human immunodeficiency virus (HIV). PATIENTS AND METHODS Initial and follow up sera from 49 children with haemophilia were analysed for the presence of GBV-C/HGV RNA and antibodies to HGV (anti-HGV). All patients had been infected with HIV while receiving concentrates without virus inactivation before 1984 and were subsequently treated with virus inactivated concentrates. RESULTS In the first available serum sample (1987 or later), two of 49 patients were GBV-C/HGV RNA positive and two further patients were anti-HGV positive. During follow up (mean, 6 years), 14 patients developed markers of GBV-C/HGV infection. Eleven of these had received no blood products except clotting factor concentrates that had been prepared with virus inactivation. CONCLUSIONS Despite being treated with virus inactivated clotting factor concentrates, HIV positive patients with haemophilia are at an increased risk of manifesting GBV-C/HGV infection. We hypothesise that GBV-C/HGV is transmitted by these clotting factor concentrates. However, we cannot rule out the emergence of markers of GBV-C/HGV infection as a result of the progression of immune impairment in the course of HIV infection.

Bakterielle Dünndarmüberwucherung Klinik, Diagnose und Therapie

ZusammenfassungBei 3 Patienten im Alter von 3 Monaten bis 5 Jahren, die zur Abklärung einer Gedeihstörung und rezidivierender Durchfälle vorgestellt wurden, konnte mittels einer Kombination von typischer Anamnese, laborchemischer, radiologischer, endoskopischer und histologischer Methoden und des H2-Atemtests die Diagnose einer bakteriellen Dünndarmüberwucherung gestellt werden. Von besonderer Bedeutung ist, daß bei allen Patienten eine Darmerkrankung vorbestand: Zwei Patienten, ehemalige Frühgeborene, waren im Rahmen einer nekrotisierenden Enterokolitis mehrfach laparotomiert worden, es bestand die Notwendigkeit zu teilweise ausgedehnten Darmresektionen. Beim 3. Patienten wurde ein langstreckiger Morbus Hirschsprung gesichert. Eine antibiotische Therapie mit Metronidazol führte in allen 3 Fällen zu einer Gewichtszunahme und Besserung der klinischen Beschwerden. Diskussion: Die bakterielle Dünndarmüberwucherung ist eine wichtige Differentialdiagnose der Gedeihstörung, insbesondere bei vorbestehender Darmerkrankung. Die Diagnose ergibt sich aus der Kombination verschiedener indirekter Untersuchungsverfahren. Ein direkter mikrobiologischer Nachweis ist schwierig. Eine antibiotische Therapie führt in der Regel zur raschen Gewichtszunahme.SummaryEvaluation of three patients, aged between three months and five years because of failure to thrive and persistent diarrhea revealed the diagnosis of small bowel bacterial overgrowth. A combination of a typical history, endoscopy, laboratory, radiological and histological methods as well as the breath hydrogen test were used. All patients had preexisting intestinal disease: two (former premature infants) had been operated several times because of necrotizing enterocolitis including resection of larger parts of small bowel. The third patient was suffering from pancolonic Hirschsprungs disease. All patients gained weight and reported less complaints after antibiotic treatment with metronidazole. Discussion: Small bowel bacterial overgrowth has to be considered in the differential diagnosis of failure to thrive, especially in cases with preexisting intestinal disease. The diagnosis may be substantiated by a combination of indirect methods. Direct bacteriologic analysis is difficult. Usually, antibiotic treatment leads to a good weight gain after a short period of time.