Impact of estrogen replacement throughout childhood on growth, pituitary-gonadal axis and bone in a 46,XX patient with CYP19A1 deficiency

The adequate replacement dose of estrogens during infancy and childhood is still not known in girls. Aromatase deficiency offers an excellent model to study how much estrogens are needed during infancy, childhood and adulthood.

Acute Encephalopathy with Unilateral Cortical-Subcortical Lesions in Two Unrelated Kindreds Treated with Glucocorticoids Prenatally for Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency: Established Facts and Novel Insight

Background: Prenatal glucocorticoid (GC) treatment of the female fetus with 21-hydroxylase deficiency (21-OHD) may prevent genital virilization and androgen effects on the brain, but prenatal GC therapy is controversial because of possible adverse effects on fetal programming, the cardiovascular system and the brain. Case Reports: We report 2 patients with congenital adrenal hyperplasia (CAH) due to 21-OHD who were treated prenatally with dexamethasone, suffered from an acute encephalopathy and showed focal and multifocal cortical and subcortical diffusion restrictions in early MRI and signs of permanent alterations in the follow-up neuroimaging studies. Both patients recovered from the acute episode. Whereas the first patient recovered without neurological sequelae the second patient showed hemianopsia and spastic hemiplegia in the neurological follow-up examination. Conclusion: These are 2 children with CAH, both treated prenatally with high doses of dexamethasone to prevent virilization. The question arises whether prenatal high-dose GC treatment in patients with CAH might represent a risk factor for brain lesions in later life. Adverse effects/events should be reported systematically in patients undergoing prenatal GC treatment and long-term follow-up studies involving risk factors for cerebrovascular disease should be performed.

Deficiency in SLC25A1, encoding the mitochondrial citrate carrier, causes combined D-2- and L-2-hydroxyglutaric aciduria

The Krebs cycle is of fundamental importance for the generation of the energetic and molecular needs of both prokaryotic and eukaryotic cells. Both enantiomers of metabolite 2-hydroxyglutarate are directly linked to this pivotal biochemical pathway and are found elevated not only in several cancers, but also in different variants of the neurometabolic disease 2-hydroxyglutaric aciduria. Recently we showed that cancer-associated IDH2 germline mutations cause one variant of 2-hydroxyglutaric aciduria. Complementary to these findings, we now report recessive mutations in SLC25A1, the mitochondrial citrate carrier, in 12 out of 12 individuals with combined D-2- and L-2-hydroxyglutaric aciduria. Impaired mitochondrial citrate efflux, demonstrated by stable isotope labeling experiments and the absence of SLC25A1 in fibroblasts harboring certain mutations, suggest that SLC25A1 deficiency is pathogenic. Our results identify defects in SLC25A1 as a cause of combined D-2- and L-2-hydroxyglutaric aciduria.

Bioinformatics tools and databases for the study of human growth hormone

Advances in novel molecular biological diagnostic methods are changing the way of diagnosis and study of metabolic disorders like growth hormone deficiency. Faster sequencing and genotyping methods require strong bioinformatics tools to make sense of the vast amount of data generated by modern laboratories. Advances in genome sequencing and computational power to analyze the whole genome sequences will guide the diagnostics of future. In this chapter, an overview of some basic bioinformatics resources that are needed to study metabolic disorders are reviewed and some examples of bioinformatics analysis of human growth hormone gene, protein and structure are provided.

Aldosterone deficiency adversely affects pregnancy outcome in mice

Circulating aldosterone levels are increased in human pregnancy. Inadequately low aldosterone levels as present in preeclampsia, a life-threatening disease for both mother and child, are discussed to be involved in its pathogenesis or severity. Moreover, inactivating polymorphisms in the aldosterone synthase gene have been detected in preeclamptic women. Here, we used aldosterone synthase-deficient (AS(-/-)) mice to test whether the absence of aldosterone is sufficient to impair pregnancy or even to cause preeclampsia. AS(-/-) and AS(+/+) females were mated with AS(+/+) and AS(-/-) males, respectively, always generating AS(+/-) offspring. With maternal aldosterone deficiency in AS(-/-) mice, systolic blood pressure was low before and further reduced during pregnancy with no increase in proteinuria. Yet, AS(-/-) had smaller litters due to loss of fetuses as indicated by a high number of necrotic placentas with massive lymphocyte infiltrations at gestational day 18. Surviving fetuses and their placentas from AS(-/-) females were smaller. High-salt diet before and during pregnancy increased systolic blood pressure only before pregnancy in both genotypes and abolished the difference in blood pressure during late pregnancy. Litter size from AS(-/-) was slightly improved and the differences in placental and fetal weights between AS(+/+) and AS(-/-) mothers disappeared. Overall, an increased placental efficiency was observed in both groups paralleled by a normalization of elevated HIF1α levels in the AS(-/-) placentas. Our results demonstrate that aldosterone deficiency has profound adverse effects on placental function. High dietary salt intake improved placental function. In this animal model, aldosterone deficiency did not cause preeclampsia.

Plakoglobin deficiency protects keratinocytes from apoptosis

The armadillo family protein plakoglobin (Pg) is a well-characterized component of anchoring junctions, where it functions to mediate cell-cell adhesion and maintain epithelial tissue integrity. Although its closest homolog beta-catenin acts in the Wnt signaling pathway to dictate cell fate and promote proliferation and survival, the role of Pg in these processes is not well understood. Here, we investigate how Pg affects the survival of mouse keratinocytes by challenging both Pg-null cells and their heterozygote counterparts with apoptotic stimuli. Our results indicate that Pg deletion protects keratinocytes from apoptosis, with null cells exhibiting delayed mitochondrial cytochrome c release and activation of caspase-3. Pg-null keratinocytes also exhibit increased messenger RNA and protein levels of the anti-apoptotic molecule Bcl-X(L) compared to heterozygote controls. Importantly, reintroduction of Pg into the null cells shifts their phenotype towards that of the Pg+/- keratinocytes, providing further evidence that Pg plays a direct role in regulating cell survival. Taken together, our results suggest that in addition to its adhesive role in epithelia, Pg may also function in contrast to the pro-survival tendencies of beta-catenin, to potentiate death in cells damaged by apoptotic stimuli, perhaps limiting the potential for the propagation of mutations and cellular transformation.Journal of Investigative Dermatology advance online publication, 16 November 2006; doi:10.1038/sj.jid.5700615.

Frequency of Malaria and Glucose-6-phosphate Dehydrogenase Deficiency in Tajikistan

Background During the Soviet era, malaria was close to eradication in Tajikistan. Since the early 1990s, the disease has been on the rise and has become endemic in large areas of southern and western Tajikistan. The standard national treatment for Plasmodium vivax is based on primaquine. This entails the risk of severe haemolysis for patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Seasonal and geographical distribution patterns as well as G6PD deficiency frequency were analysed with a view to improve understanding of the current malaria situation in Tajikistan. Methods Spatial and seasonal distribution was analysed, applying a risk model that included key environmental factors such as temperature and the availability of mosquito breeding sites. The frequency of G6PD deficiency was studied at the health service level, including a cross-sectional sample of 382 adult men. Results Analysis revealed high rates of malaria transmission in most districts of the southern province of Khatlon, as well as in some zones in the northern province of Sughd. Three categories of risk areas were identified: (i) zones at relatively high malaria risk with high current incidence rates, where malaria control and prevention measures should be taken at all stages of the transmission cycle; (ii) zones at relatively high malaria risk with low current incidence rates, where malaria prevention measures are recommended; and (iii) zones at intermediate or low malaria risk with low current incidence rates where no particular measures appear necessary. The average prevalence of G6PD deficiency was 2.1% with apparent differences between ethnic groups and geographical regions. Conclusion The study clearly indicates that malaria is a serious health issue in specific regions of Tajikistan. Transmission is mainly determined by temperature. Consequently, locations at lower altitude are more malaria-prone. G6PD deficiency frequency is too moderate to require fundamental changes in standard national treatment of cases of P. vivax.

Alteration of the pulmonary surfactant system in full-term infants with hereditary ABCA3 deficiency

RATIONALE: ABCA3 mutations are known to cause fatal surfactant deficiency. OBJECTIVE: We studied ABCA3 protein expression in full-term newborns with unexplained respiratory distress syndrome (URDS) as well as the relevance of ABCA3 mutations for surfactant homeostasis. METHODS: Lung tissue of infants with URDS was analyzed for the expression of ABCA3 in type II pneumocytes. Coding exons of the ABCA3 gene were sequenced. Surfactant protein expression was studied by immunohistochemistry, immunoelectron microscopy, and Western blotting. RESULTS: ABCA3 protein expression was found to be greatly reduced or absent in 10 of 14 infants with URDS. Direct sequencing revealed distinct ABCA3 mutations clustering within vulnerable domains of the ABCA3 protein. A strong expression of precursors of surfactant protein B (pro-SP-B) but only low levels and aggregates of mature surfactant protein B (SP-B) within electron-dense bodies in type II pneumocytes were found. Within the matrix of electron-dense bodies, we detected precursors of SP-C (pro-SP-C) and cathepsin D. SP-A was localized in small intracellular vesicles, but not in electron-dense bodies. SP-A and pro-SP-B were shown to accumulate in the intraalveolar space, whereas mature SP-B and SP-C were reduced or absent, respectively. CONCLUSION: Our data provide evidence that ABCA3 mutations are associated not only with a deficiency of ABCA3 but also with an abnormal processing and routing of SP-B and SP-C, leading to severe alterations of surfactant homeostasis and respiratory distress syndrome. To identify infants with hereditary ABCA3 deficiency, we suggest a combined diagnostic approach including immunohistochemical, ultrastructural, and mutation analysis.

Transient MR changes and symptomatic epilepsy following gamma knife treatment of a residual GH-secreting pituitary adenoma in the cavernous sinus

To report a rare side effect of gamma knife treatment of pituitary macroadenoma.

[A young child with acute abdomen and iron deficiency anemia]

The case of a 20 month-old girl that was admitted to the emergency ward because of worsening of her general condition in the setting of acute non-bloody gastroenteritis is reported. The clinical examination revealed signs of severe dehydration and a prominent tender abdomen. Laboratory evaluation showed leucocytosis, elevated C-reactive protein and severe hypochromic microcytic anemia. Abdominal X-ray revealed diffuse meteorism. The child underwent laparascopic evaluation. A perforated Meckel's diverticulum was found. Perforation and anemia due to occult bleeding are unusual presentations of Meckel's diverticulum. The differential diagnosis of children presenting with an acute abdomen with special focus on Meckel's diverticulum is discussed.

Characterisation of six novel A-subunit mutations leading to congenital factor XIII deficiency and molecular analysis of the first diagnosed patient with this rare bleeding disorder

In 1960, the first case report on factor XIII deficiency was published describing a seven-year-old Swiss boy with a so far unknown bleeding disorder. Today, more than 60 mutations in the factor XIIIA- and B-subunit genes are known leading to congenital factor XIII deficiency. In the present study, we describe six novel mutations in the factor XIII A-subunit gene. Additionally, we present the molecular characterisation of the first described patient with congenital factor XIII deficiency. The six novel mutations include a small deletion, Glu202 delG, leading to a premature stop codon and truncation of the protein, and a splice site mutation at the exon 10/intron 10 boundary, +1G/A, giving rise to an incorrect spliced mRNA lacking exons 10 and 11. The remaining four mutations are characterised by the single amino acid changes Met159Arg, Gly215Arg, Trp375Cys, and His716Arg, and were expressed in COS-1 cells. Antigen levels and activity of the mutants were significantly reduced compared to the wild-type. The patient described in 1960 also shows a single amino acid change, Arg77Cys. Structural analysis of all mutant enzymes suggests several mechanisms leading to destabilisation of the protein.

P450 oxidoreductase deficiency: a new form of congenital adrenal hyperplasia

PURPOSE OF REVIEW: P450 oxidoreductase deficiency--a newly described form of congenital adrenal hyperplasia--typically presents a steroid profile suggesting combined deficiencies of steroid 21-hydroxylase and 17alpha-hydroxylase/17,20-lyase activities. These and other enzymes require electron donation from P450 oxidoreductase. The clinical spectrum of P450 oxidoreductase deficiency ranges from severely affected children with ambiguous genitalia, adrenal insufficiency and the Antley-Bixler skeletal malformation syndrome to mildly affected individuals with polycystic ovary syndrome. We review current knowledge of P450 oxidoreductase deficiency and its broader implications. RECENT FINDINGS: Since the first report in 2004, at least 21 P450 oxidoreductase mutations have been reported in over 40 patients. The often subtle manifestations of P450 oxidoreductase deficiency suggest it may be relatively common. P450 oxidoreductase deficiency, with or without Antley-Bixler syndrome, is autosomal recessive, whereas Antley-Bixler syndrome without disordered steroidogenesis is caused by autosomal dominant fibroblast growth factor receptor 2 mutations. In-vitro assays of P450 oxidoreductase missense mutations based on P450 oxidoreductase-supported P450c17 activities provide excellent genotype/phenotype correlations. The causal connection between P450 oxidoreductase deficiency and disordered bone formation remains unclear. SUMMARY: P450 oxidoreductase mutations cause combined partial deficiency of 17alpha-hydroxylase and 21-hydroxylase. Individuals with an Antley-Bixler syndrome-like phenotype presenting with sexual ambiguity or other abnormalities in steroidogenesis should be analyzed for P450 oxidoreductase deficiency.

Deficiency in parvalbumin, but not in calbindin D-28k upregulates mitochondrial volume and decreases smooth endoplasmic reticulum surface selectively in a peripheral, subplasmalemmal region in the soma of Purkinje cells

The Ca(2+)-binding proteins parvalbumin (PV) and calbindin D-28k (CB) are key players in the intracellular Ca(2+)-buffering in specific cells including neurons and have profound effects on spatiotemporal aspects of Ca(2+) transients. The previously observed increase in mitochondrial volume density in fast-twitch muscle of PV-/- mice is viewed as a specific compensation mechanism to maintain Ca(2+) homeostasis. Since cerebellar Purkinje cells (PC) are characterized by high expression levels of the Ca(2+) buffers PV and CB, the question was raised, whether homeostatic mechanisms are induced in PC lacking these buffers. Mitochondrial volume density, i.e. relative mitochondrial mass was increased by 40% in the soma of PV-/- PC. Upregulation of mitochondrial volume density was not homogenous throughout the soma, but was selectively restricted to a peripheral region of 1.5 microm width underneath the plasma membrane. Accompanied was a decreased surface of subplasmalemmal smooth endoplasmic reticulum (sPL-sER) in a shell of 0.5 microm thickness underneath the plasma membrane. These alterations were specific for the absence of the "slow-onset" buffer PV, since in CB-/- mice neither changes in peripheral mitochondria nor in sPL-sER were observed. This implicates that the morphological alterations are aimed to specifically substitute the function of the slow buffer PV. We propose a novel concept that homeostatic mechanisms of components involved in Ca(2+) homeostasis do not always occur at the level of similar or closely related molecules. Rather the cell attempts to restore spatiotemporal aspects of Ca(2+) signals prevailing in the undisturbed (wildtype) situation by subtly fine tuning existing components involved in the regulation of Ca(2+) fluxes.