Favourable long-term outcome after immediate treatment of neonatal hyperammonemia due to N-acetylglutamate synthase deficiency

INTRODUCTION: N-Acetylglutamate synthase (NAGS) deficiency is a rare urea cycle disorder, which may present in the neonatal period with severe hyperammonemia and marked neurological impairment. CASE REPORT: We report on a Turkish family with a patient who died due to hyperammonemia in the neonatal period. Reduced activity of NAGS and carbamyl phosphate synthetase were found at autopsy. A second child who developed hyperammonemia on the second day of life was immediately treated with arginine hydrochloride, sodium benzoate and protein restriction. After NAGS deficiency was suspected by enzyme analysis, sodium benzoate was replaced by N-carbamylglutamate (NCG). A third child who developed slight hyperammonemia on the third day of life was treated with NCG before enzyme analysis confirmed reduced NAGS activity. Neither of the patients developed hyperammonemia in the following years. After the human NAGS gene was identified, mutation analysis revealed that the older sibling on NCG therapy was homozygous for a 971G>A (W324X) mutation. The parents and the younger sibling were heterozygous. Therapy was continued in the older sibling until now without any adverse effects and favourable neurodevelopment outcome. In the younger sibling, therapy was stopped without any deterioration of urea cycle function. CONCLUSION: NAGS deficiency can be successfully treated with NCG and arginine hydrochloride with favourable outcome. Molecular diagnostic rather than enzyme analysis should be used in patients with suspected NAGS deficiency.

Adult-onset ornithine transcarbamylase (OTC) deficiency unmasked by the Atkins' diet

Late-onset symptoms of urea-cycle disorder may lead to a life-threatening disease which is often undetected. We report the clinical and metabolic manifestations of acute hyperammonemic encephalopathy in a 47-year-old asymptomatic man with ornithine transcarbamylase (OTC) deficiency. The hyperammonemic encephalopathy was unmasked by a high-protein Atkins diet.

Effect of Growth Hormone (GH) on Fasting and Postprandial Metabolism in GH Deficiency

Hypopituitarism with adult-onset growth hormone deficiency (GHD) is associated with increased cardiovascular morbidity and mortality due to premature and progressive atherosclerosis. An underlying cause of atherosclerosis is increased insulin resistance. Elevated fasting and postprandial glucose and lipid levels may contribute to premature atherosclerosis. We studied effects of growth hormone replacement (GHRT) on fasting and postprandial metabolic parameters as well as on insulin sensitivity in patients with adult-onset GHD.

Hyponatremia associated coma due to pituitary apoplexy in early pregnancy: a case report

Pituitary apoplexy in pregnancy is rare. Its clinical features may range from unspecific complaints to panhypopituitarism resulting even in coma and death. Therefore, alertness to signs and symptoms of acute loss of pituitary function in pregnancy is mandatory. We report a woman in her 7th week of her first gestation presenting with sudden coma due to severe hyponatremia. Secondary adrenal insufficiency could be identified as the underlying cause. Panhypopituitarism including central diabetes insipidus and spontaneous abortion developed during the follow-up. Magnetic resonance imaging showed pituitary apoplexy without a pre-existing pituitary mass. The clinical course was notable for severe complications, including neurological deficits through cerebral ischemia, but eventual recovery could be achieved. We discuss the diagnostic difficulties in the evaluation of pituitary disease in pregnancy.

Mutations affecting disulphide bonds contribute to a fairly common prevalence of F13B gene defects: results of a genetic study in 14 families with factor XIII B deficiency

Severe factor XIII (FXIII) deficiency is a rare autosomal recessive coagulation disorder affecting one in two million individuals. The aim of the present study was to screen for and analyse F13B gene defects in the German population. A total of 150 patients presenting with suspected FXIII deficiency and one patient with severe (homozygous) FXIII deficiency were screened for mutations in F13A and F13B genes. Twenty-five individuals presented with detectable heterozygous mutations, 12 of them in the F13A gene and 13 of them in the F13B gene. We report on the genotype-phenotype correlations of the individuals showing defects in the F13B gene. Direct sequencing revealed 12 unique mutations including seven missense mutations (Cys5Arg, Ile81Asn, Leu116Phe, Val217Ile, Cys316Phe, Val401Glu, Pro428Ser), two splice site mutations (IVS2-1G>C, IVS3-1G>C), two insertions (c.1155_1158dupACTT, c.1959insT) and one in-frame deletion (c.471-473delATT). Two of the missense mutations (Cys5Arg, Cys316Phe) eliminated disulphide bonds (Cys5-Cys56, Cys316-Cys358). Another three missense mutations, (Leu116Phe, Val401Glu, Pro428Ser) were located proximal to other cysteine disulphide bonds, therefore indicating that the region in and around these disulphide bonds is prone to functionally relevant mutations in the FXIII-B subunit. The present study reports on a fairly common prevalence of F13B gene defects in the German population. The regions in and around the cysteine disulphide bonds in the FXIII-B protein may be regions prone to frequent mutations.

Pituitary surgery for small prolactinomas as an alternative to treatment with dopamine agonists

Despite the fact that consensus guidelines recommend long-term dopamine agonist (DA) therapy as a first-line approach to the treatment of small prolactinoma, some patients continue to prefer a primary surgical approach. Concerns over potential adverse effects of long-term medical therapy and/or the desire to become pregnant and avoid long-term medication are often mentioned as reasons to pursue surgical removal. In this retrospective study, 34 consecutive patients (30 female, 4 male) preferably underwent primary pituitary surgery without prior DA treatment for small prolactinomas (microprolactinoma 1-10 mm, macroprolactinoma 11-20 mm) at the Department of Neurosurgery, University of Bern, Switzerland. At the time of diagnosis, 31 of 34 patients (91%) presented with symptoms. Patients with microprolactinomas had significantly lower preoperative prolactin (PRL) levels compared to patients with macroprolactinomas (median 143 μg/l vs. 340 μg/l). Ninety percent of symptomatic patients experienced significant improvement of their signs and symptoms upon surgery. The postoperative PRL levels (median 3.45 μg/l) returned to normal in 94% of patients with small prolactinomas. There was no mortality and no major morbidities. One patient suffered from hypogonadotropic hypogonadism after surgery despite postoperative normal PRL levels. Long-term remission was achieved in 22 of 24 patients (91%) with microprolactinomas, and in 8 of 10 patients (80%) with macroprolactinomas after a median follow-up period of 33.5 months. Patients with small prolactinomas can safely consider pituitary surgery in a specialized centre with good chance of long-term remission as an alternative to long-term DA therapy.

Mannan-binding lectin deficiency results in unusual antibody production and excessive experimental colitis in response to mannose-expressing mild gut pathogens

In Crohn's disease (CD) the deficiency of mannan-binding lectin (MBL) is associated with an increased prevalence of anti-Saccharomyces cerevisiae antibodies (ASCA) and with complicated phenotypes of the disease. However, the role of MBL in intestinal inflammation is currently unclear. A study was undertaken to analyse local MBL expression in human intestine and the consequences of MBL deficiency in experimental colitis and yeast infection.

Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment

Clinical manifestations of lactase (LCT) deficiency include intestinal and extra-intestinal symptoms. Lactose hydrogen breath test (H2-BT) is considered the gold standard to evaluate LCT deficiency (LD). Recently, the single-nucleotide polymorphism C/T(-13910) has been associated with LD. The objectives of the present study were to evaluate the agreement between genetic testing of LCT C/T(-13910) and lactose H2-BT, and the diagnostic value of extended symptom assessment. Of the 201 patients included in the study, 194 (139 females; mean age 38, range 17-79 years, and 55 males, mean age 38, range 18-68 years) patients with clinical suspicion of LD underwent a 3-4 h H2-BT and genetic testing for LCT C/T(-13910). Patients rated five intestinal and four extra-intestinal symptoms during the H2-BT and then at home for the following 48 h. Declaring H2-BT as the gold standard, the CC(-13910) genotype had a sensitivity of 97% and a specificity of 95% with a of 0.9 in diagnosing LCT deficiency. Patients with LD had more intense intestinal symptoms 4 h following the lactose challenge included in the H2-BT. We found no difference in the intensity of extra-intestinal symptoms between patients with and without LD. Symptom assessment yielded differences for intestinal symptoms abdominal pain, bloating, borborygmi and diarrhoea between 120 min and 4 h after oral lactose challenge. Extra-intestinal symptoms (dizziness, headache and myalgia) and extension of symptom assessment up to 48 h did not consistently show different results. In conclusion, genetic testing has an excellent agreement with the standard lactose H2-BT, and it may replace breath testing for the diagnosis of LD. Extended symptom scores and assessment of extra-intestinal symptoms have limited diagnostic value in the evaluation of LD.

[Acrodermatitis enteropathica-like skin lesions due to Crohn's disease-associated zinc deficiency]

We report a case of acrodermatitis enteropathica-like skin eruptions presenting with alopecia, perlèche, glossitis, and genital erosions as well as multifocal eczematoid, psoriasiform, and bullous skin lesions due to zinc deficiency in Crohn's disease.

High prevalence of severe vitamin D deficiency in combined antiretroviral therapy-naive and successfully treated Swiss HIV patients

To evaluate the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in HIV-positive patients, a population at risk for osteoporosis.

Clinical and biochemical consequences of p450 oxidoreductase deficiency

Patients with P450 oxidoreductase (POR) deficiency typically present with adrenal insufficiency, genital anomalies and bony malformations resembling the Antley-Bixler craniosynostosis syndrome. Since our first report in 2004, more than 40 POR mutations have been identified in over 65 patients. POR is the obligate electron donor to all microsomal P450 enzymes, including the steroidogenic enzymes CYP17A1, CYP21A2 and CYP19A1. POR deficiency may cause disordered sexual development manifested as genital undervirilization in 46, XY newborns as well as overvirilization in those who are 46, XX. This may be explained by impaired aromatization of fetal androgens that may cause maternal virilization and low urinary estriol levels during pregnancy. In addition, the alternate 'backdoor' pathway of androgen biosynthesis, which leads to dihydrotestosterone production bypassing androstenedione and testosterone, may also play a role. Functional assays studying the effects of POR mutations on steroidogenesis showed that several POR variants impaired CYP17A1, CYP21A2 and CYP19A1 activities to different degrees, indicating that each POR variant must be studied separately for each potential target P450 enzyme. POR variants may also affect skeletal development and drug metabolism. As most drugs are metabolized by hepatic microsomal P450 enzymes, studies of the impact of POR mutations on drug-metabolizing P450s are particularly important.

Diagnosis and treatment of iron-deficiency anaemia during pregnancy and postpartum

Iron-deficiency anaemia during pregnancy and postpartum occurs frequently and may lead to severe maternal and foetal complications. New treatment regimens include intravenous iron administration in particular clinical situations. The aim of the study was to determine optimal diagnostic and therapeutic approaches to iron-deficiency anaemia during pregnancy and postpartum.