Trichobezoar in a child with concomitant coeliac disease: a case report.

UNLABELLED: We report on a case of childhood coeliac disease presenting with tricophagia and trichobezoar. The combination of obstructive symptoms, severe hypoalbuminaemia and a large abdominal mass detected on CT scan warranted diagnostic gastroscopy and laparotomy, resulting in removal of a large gastric trichobezoar. Surgical recovery was uneventful although serologic studies for coeliac disease were abnormal. Coeliac disease was confirmed by subsequent biopsy. CONCLUSION: Concomitant trichobezoar and coeliac disease in a child is reported for the first time. It is postulated that the trichobezoar was a result of coeliac disease-induced pica.

Screening for mutations and polymorphisms in the genes KCNH2 and KCNE2 encoding the cardiac HERG/MiRP1 ion channel: implications for acquired and congenital long Q-T syndrome.

BACKGROUND: The voltage-gated, rapid-delayed rectifier current (I(Kr)) is important for repolarization of the heart, and mutations in the genes coding for the K+-ion channel conducting this current, i.e., KCNH2 for the alpha-subunit HERG and KCNE2 for the beta-subunit MiRP1, cause acquired and congenital long Q-T syndrome (LQTS) and other cardiac arrhythmias. METHODS: We developed a robust single-strand conformation polymorphism-heteroduplex screening analysis, with identical thermocycling conditions for all PCR reactions, covering all of the coding exons in KCNH2 and KCNE2. The method was used to screen 40 unrelated LQTS patients. RESULTS: Eleven mutations, of which six were novel, were found in KCNH2. Interestingly, six mutations were found in the region of the gene coding for the Per-Arnt-Sim (PAS) and PAS-S1 regions of the HERG protein, stressing the need to examine the entire gene when screening for mutations. No mutations were found in KCNE2, suggesting that direct involvement of MiRP1 in LQTS is rare. Furthermore, four novel single-nucleotide polymorphisms (SNPs) and one amino acid polymorphism (R1047L) were identified in KCNH2, and one novel SNP and one previously known amino acid polymorphism (T8A) were found in KCNE2. CONCLUSIONS: The potential role of rare polymorphisms in the HERG/MiRP1 K+-channel should be clarified with respect to drug interactions and susceptibility to arrhythmia and sudden death.

[Molecular genetics of the long QT syndrome. Genes causing syncope and sudden death]. / Molekylärgenetik vid långt QT-syndrom. Gener som orsakar svimning och plötslig död.

Molecular genetic studies in congenital long QT syndrome have characterized genes and mechanisms of arrhythmias. At least six genes encoding cardiac potassium and sodium ionic channels have been described with several mutations in each gene. The altered function produces abnormal cardiac repolarization seen on ECG as prolongation of the QT-interval and T-wave abnormalities. This may increase the propensity for ventricular arrhythmias such as Torsade de Pointe, the cause of unexpected syncope and sudden death in young patients. Clinical manifestations vary depending on the genotype present. Gene-specific therapies have recently been tried. Initial therapy of choice for symptomatic and also asymptomatic children is administration of beta-blockers.

A cohort study of childhood hypertrophic cardiomyopathy: improved survival following high-dose beta-adrenoceptor antagonist treatment.

OBJECTIVES: The study analyzed factors, including treatment, affecting disease-related death in patients with hypertrophic cardiomyopathy (HCM) presenting in childhood. BACKGROUND: Previous smaller studies suggest that mortality is higher in patients with HCM presenting in childhood compared with presentation in adulthood, but these studies have all originated from selected patient populations in tertiary referral centers, and reported no significant protection by treatment. METHODS: Retrospective comparisons of mortality were done in total cohort of patients presenting to three regional centers of pediatric cardiology. There were 66 patients (25 with Noonan's syndrome) with HCM presenting at age <19 years; mean follow-up was 12.0 years. RESULTS: Among risk factors for death were congestive heart failure (p = 0.008), large electrocardiogram voltages (Sokolow-Lyon index p = 0.0003), and degree of septal (p = 0.004) and left ventricular (p = 0.028) hypertrophy expressed as percent of 95th centile value. The only treatment that significantly reduced the risk of death on multifactorial analysis of variance was high-dose beta-adrenoceptor antagonist therapy (propranolol 5 to 23 mg/kg/day or equivalent; p = 0.0001). Nineteen out of 40 patients managed conventionally (no treatment, 0.8 to 4 mg/kg of propranolol, or verapamil) died, median survival 15.8 years, with no deaths among 26 patients on high-dose beta-blockers (p = 0.0004); survival proportions at 10 years were 0.65 (95% confidence interval 0.49-0.80) and 1.0, respectively (p = 0.0015). Survival time analysis shows better survival in the high-dose beta-blocker group compared with the "no specific therapy" group (p = 0.0009) and with the conventional-dose beta-blocker group (p = 0.002). Hazard ratio analysis suggests that high-dose beta-blocker therapy produces a 5-10-fold reduction in the risk of disease-related death. CONCLUSIONS: High-dose beta-blocker therapy improves survival in childhood HCM.

Pharmacokinetics of bambuterol during oral administration to asthmatic children.

AIMS: To investigate dose proportionality, dosing frequency, and ethnic aspects of the pharmacokinetics of bambuterol in asthmatic children, and to discuss the relationship with previous observations in adults. METHODS: Forty-eight children in four different studies completed two double-blind bambuterol treatments each (daily doses of bambuterol hydrochloride): 12 preschool (5 mg x 2 vs 10 mg) and 12 school (10 mg vs 20 mg) Caucasians, 12 preschool (2.5 mg vs 5 mg), and 12 school (10 mg vs 20 mg) Orientals. Peak plasma concentrations and dosing interval area under curve (AUC) of bambuterol and the active metabolite terbutaline were assessed at steady state. Treatment differences were analysed statistically within each study. Differences between the studies and the relation to steady-state AUC in adults were described. RESULTS: Dose proportionality was seen for terbutaline but not for bambuterol. Twice-daily dosing (2 x AUC(0,12 h)) could not be shown to differ from once-daily dosing (AUC(0,24 h)) in the preschool Caucasians. Mean AUC of terbutaline was 128 and 242 nmol l-1 h in the preschool Caucasians (5 mg/12 h; 10 mg/24 h), 213 and 406 nmol l-1 h in the Caucasian school children (10 mg; 20 mg), 87.4 and 202 nmol l-1 h in the Oriental preschool children (2.5 mg; 5 mg), and 356 and 640 nmol l-1 h in the Oriental school children (10 mg; 20 mg). Oriental school children had higher plasma concentrations of bambuterol and terbutaline than Caucasian school children. The strict ethnic implication of the difference could not be elucidated, because demographic data were not perfectly matched. Terbutaline AUC was only moderately increased in the Caucasian school children compared with Caucasian adults. The increase was more pronounced in Oriental children and in some preschool Caucasians. The highest concentration of terbutaline, 58 nmol l-1, was seen in an Oriental school child after a 20 mg dose. CONCLUSIONS: Caucasian school children can be given bambuterol hydrochloride very much as Caucasian adults, 10 or 20 mg once daily, but Oriental preschool and school children plus preschool Caucasians should be given lower doses.

Recessive Romano-Ward syndrome associated with compound heterozygosity for two mutations in the KVLQT1 gene.

We describe a Swedish family with the proband and his brother suffering from severe Romano-Ward syndome (RWS) associated with compound heterozygosity for two mutations in the KVLQT1 (also known as KCNQ1 and KCNA9) gene (R518X and A525T). The mutations were found to segregate as heterozygotes in the maternal and the paternal lineage, respectively. None of the heterozygotes exhibited clinical long QT syndrome (LQTS). No hearing defects were found in the proband. The data strongly indicates that the compound heterozygosity for R518X and A525T is the cause of an autosomal recessive form of RWS in this family. Our findings support the implication of a higher frequency of gene carriers than previously expected. We suggest that relatives of 'sporadic RWS' patients should be considered potential carriers, at risk of dying suddenly from drug-induced LQTS.

An individual with a healthy phenotype in spite of a pathogenic LDL receptor mutation (C240F).

Familial hypercholesterolemia (FH) is caused by a defect in the function of the low density lipoprotein (LDL) receptor and inherited in an autosomal, codominant way. In this study we present a 13-year-old girl, compound heterozygote for the LDL receptor mutations C240F and Y167X. Fibroblasts from the patient showed very low cholesterol esterification rate, LDL uptake, and degradation compared to normal fibroblasts (< 2%, 8%, and < 2%, respectively). The C240F mutant was expressed in LDL receptor deficient CHOMldlA7 cells. Analysis of cell extracts by immunoblotting demonstrated delayed processing of the mutated LDL receptor, which was accumulated as a precursor protein of normal size. A high molecular weight form of the receptor was also detectable in these cells, which probably reflects cross-linking through the unpaired cysteine residue in the binding domain. Cells expressing the C240F mutant protein were unable to mediate uptake and degradation of LDL. The two siblings of the index case also carried the C240F mutation, but surprisingly one of them (a 17-year-old brother) showed no signs of hypercholesterolemia. This observation is consistent with the view that there may be cholesterol lowering mechanisms that can be activated, perhaps by mutations in known or hitherto unknown genes.

A missense mutation in the hypoxanthine phosphoribosyltransferase gene in a pediatric patient with hyperuricemia.

We have identified a mutation in the gene coding for the enzyme hypoxanthine phosphoribosyltransferase in a pediatric patient with hyperuricemia and nephrolithiasis. The mutation is a nucleotide substitution causing an amino acid substitution in the hypoxanthine phosphoribosyltransferase protein. In this patient, fibroblasts but not lymphocytes showed resistance to 6-thioguanine, and reduced enzyme activity was detected in lymphocytes. These results are consistent with the intermediary phenotype associated with partial hypoxanthine phosphoribosyltransferase enzyme deficiency. Altogether, six males in this family suffered from hyperuricemic symptoms, and small differences in phenotype were seen.

Primary infantile hypomagnesaemia; report of two cases and review of literature.

We describe two male infants suffering from primary hypomagnesaemia, diagnosed at 3 months and 2.5 months of age. They both presented with generalised convulsions, with case 2 exhibiting hypocalcaemia which did not respond to calcium and case 1 having normocalcaemia at first but hypocalcaemia 3 days after admission. Both improved dramatically after initiation of magnesium therapy. A carrier-mediated transport defect is the most likely cause of this disease. It is of the utmost importance that a correct and prompt diagnosis be made as therapy is simple and effective. Failure in diagnosing this condition could prove fatal as demonstrated in the family history of case 2.

Pharmacokinetics of intravenous terbutaline in asthmatic children.

Seven asthmatic children were given terbutaline intravenously. The intact drug was measured in plasma and urine, and its conjugates were measured in urine. The decreasing plasma concentrations of terbutaline did not attain a terminal slope until 8-12 h after dosing. This was most likely due to different kinetics of the enantiomers. The terminal half-life was 8.8-15.8 h. Body clearance was 2.73-5.44 ml/min/kg, two-thirds of which were of renal origin. The volume of distribution (Vss) was 1.28-1.83 l/kg. The disposition pharmacokinetics of terbutaline do not rationalize a higher dose per kg body weight in children than in adults.

Apparently normal phenytoin metabolism in a patient with phenytoin-induced rash and lymphadenopathy.

A 10-year old female on phenytoin therapy developed a rash and lymphadenopathy. H.p.l.c. assays of urinary metabolites indicated no differences in stereoselective metabolism of phenytoin to phenolic and dihydrodiol metabolites as compared with volunteers given the drug or with pediatric patients without adverse reactions. This suggests that no obvious difference in stereoselective metabolism of phenytoin to potentially toxic arene oxides exists between this patient and other patients on phenytoin. Our results are consistent with the hypothesis that differences in peripheral detoxication of phenytoin arene oxides and not differences in hepatic metabolism of phenytoin may be responsible for such adverse reactions.

Terbutaline slow-release tablets in children with bronchial asthma. Effect and pharmacokinetics compared with plain terbutaline tablets.

The effect of terbutaline sulphate in slow-release (SR) tablets (Bricanyl Depot), 5 mg twice daily, was compared with that of terbutaline sulphate in ordinary tablets (Bricanyl), 2.5 mg three times daily, in a double-blind, randomized, cross-over study during 2 consecutive weeks in 10 asthmatic children. Plasma concentrations and urinary excretion of terbutaline were measured at various times during both treatment periods. The SR tablets produced a higher mean plasma concentration in the morning and a smaller peak-trough variation over the day than the ordinary ones. No differences between the two treatments were observed concerning FEV1 (forced expiratory volume in 1 s). Tremor, measured with an opto-electronic tremorgraph, was about the same for two treatments and not significantly different from tremor seen in healthy children. The reported side effects were less frequent in the SR tablet period.

Management of pituitary gigantism. The role of bromocriptine and radiotherapy.

True gigantism with overproduction of growth hormone (GH) and prolactin (PRL) was diagnosed in two boys, aged 13 years (case I) and 7 1/2 years (case II). Both had shown increased growth rates since early childhood (from 4 years and 1 1/2 years, respectively), but no skeletal acromegalic features were noted. However, both showed increased sweating and both had advanced pubic hair relative to testis volume. No other pituitary dysfunction was recorded. Case I underwent transsphenoidal surgery with only incomplete and temporary suppression of GH and PRL levels. However, in both patients bromocriptine administration promptly suppressed PRL levels. Following combined irradiation and bromocriptine treatment, GH also gradually normalized over a period of 2 years. Both boys are still on treatment, and both showed an increase in plasma GH concentrations when the dose of bromocriptine was reduced or discontinued, indicating that even 3 1/2-5 years after irradiation therapy (and during continuous treatment with bromocriptine) the disease was controlled but not cured. However, in these two boys bromocriptine has proved effective in controlling the PRL/GH oversecretion.

Prednisolone excretion in human milk.

Six lactating women receiving long-term treatment with prednisolone in doses from 10 to 80 mg/day were studied. Serum and milk samples were assayed for prednisolone and endogenous cortisol by a specific high-performance liquid chromatographic method. The milk and serum concentrations vs time curves for prednisolone were virtually parallel, and the milk concentrations were 5% to 25% of those in serum. The milk/serum concentration ratio increased with increasing serum concentration. At a daily dose of 80 mg prednisolone, the infant would ingest less than 0.1% of that dose; this corresponds to less than 10% of the infant's endogenous cortisol production. Because there is an equilibrium between the concentration of prednisolone in milk and serum, the exposure of the infant is minimized if breast-feeding is avoided during the first 4 hours after the dose. We conclude that from a quantitative point of view the exposure of the infant is minimal, and breast-feeding may be permitted at maternal prednisolone doses of at least 20 mg once or twice daily. At higher doses, exposure may be minimized if nursing is performed greater than 4 hours after the dose.