Vitamin D status and the immune assessment in 22q11.2 deletion syndrome.

22q11.2 deletion syndrome (22q11.2DS) is characterized by a heterogeneous phenotype, including alterations in phospho-calcium metabolism and immunodeficiency. We analyzed vitamin D status and the immune assessment, focusing on T cell subpopulations and dendritic cells (DCs) in a cohort of 17 pediatric 22q11.2DS patients and 17 age-matched healthy subjects. As antigen-presenting cells, DCs are the main target of vitamin D, promoting a tolerogenic T cell response. Patients were subdivided into three groups according to the parameters of phospho-calcium metabolism and serum levels of 25OHD: normal values, vitamin D deficiency and hypoparathyroidism. Different degrees of T cell deficiency, ranging from normal to partial T cell numbers, were observed in the cohort of patients. The group with vitamin D deficiency showed a significant reduction of naive T cells and a significant increase of central memory T cells compared to controls. In this group the number of circulating DCs was significantly reduced. DC decrease affected both myeloid and plasmacytoid DC subsets (mDCs and pDCs), with the most relevant reduction involving pDCs. A direct correlation between 25OHD levels and recent thymic emigrant (RTE) and DC number was identified. Despite the limited cohort analyzed, our results show that deficiency of the pDC subset in patients with 22q11.2DS may be included among the causative factors of the progressive increase of risk of autoimmune diseases in these patients. As most patients suffer from increased susceptibility to infections and heightened prevalence of autoimmune disorders, we suggest a potential role of vitamin D supplementation in preventing autoimmune or proinflammatory diseases in 22q11.2DS.

Methylenetetrahydrofolate reductase polymorphism (MTHFR C677T) and headache in children: a retrospective study from a tertiary level outpatient service.

BACKGROUND: In adult studies the MTHFR C677T polymorphism has been associated with an increased risk of migraine, but little research has been done in this area in children. METHODS: A retrospective study of children referred with headache to a tertiary level Paediatric Neurology Service between 2008 and 2012. This study included only patients who had been genotyped for the MTHFR C677T polymorphism. An evaluation of homocysteine serum levels was necessary to exclude other types of migraine. CONCLUSION: Compared with the wild-type genotype, the T/T genotype was associated with an increased risk of any type of migraine, though the statistical significance was greatest in migraine with aura. The homocysteine serum levels were significantly higher in migraine with aura compared to migraine without aura. In a pediatric population MTHFR T/T homozygosity influences susceptibility to migraine.

Generalized epilepsy and mild intellectual disability associated with 13q34 deletion: A potential role for SOX1 and ARHGEF7.

Terminal deletions of long arm of chromosome 13 are rare and poorly characterized by cytogenetic studies, making for difficult genotype-phenotype correlations. We report two siblings presenting generalized epilepsy, intellectual disability, and genitourinary tract defects. Array CGH detected a 1.3 Mb deletion at 13q34; it contains two protein-coding genes, SOX1 and ARHGEF7, whose haploinsufficiency can contribute to the epileptic phenotype.

17q12 microduplications: a challenge for clinicians.

In the recent years, some cases of 17q12 deletions and duplications have been reported, but the clinical impact of these imbalances is still to be fully elucidated. In particular, 17q12 duplications elude syndrome classification, since they are associated with a wide phenotypic spectrum, ranging from very mild to quite severe phenotypes. Here, two unrelated patients with the same 1.2 Mb microduplication of 17q12 are reported. Comparing these patients' phenotype with those previously published, it emerges that the more patients reported, the more difficult is finding common characteristics, even in presence of exactly the same genetic anomaly. The role of the genes duplicated in this region and the impact of this chromosomal imbalance are discussed.

45,X maleness: clinical and cytogenetic features in two patients.

45,X maleness is a very rare disorder. We report on 2 new 45,X males aged 9 10/12 and 39 years, respectively. The boy presented for developmental delay, while the man was referred to us because of infertility. Both patients showed short stature (boy -2.29 SDS, man -4.05 SDS) and an unbalanced translocation of Yp, including SRY, onto the long arm of chromosome 10 and short arm of chromosome 14, respectively. The growth pattern of the 2 patients and literature data suggest the presence of a specific growth gene in the pericentrometric region of Yq. In addition, developmental delay in some 45,X males may be related to specific deletion of telomeric autosome regions, but involvement of gene(s) on the Y chromosome may play a role as well. Albeit in the boy inhibin B levels were in the normal range for age, azoospermia was demonstrated in the adult, supporting that infertility is a feature of adult 45,X men with AZFa-c deletion.

Characterization of the phenotype and definition of the deletion in a new patient with ring chromosome 22.

The clinical phenotype of patients with ring chromosome 22 includes mental retardation with severe language impairment, hypotonia, and dysmorphic facial features. In recent years an increasing number of patients with microscopic as well as cryptic terminal deletion involving band 22q13 have been described and their phenotype shows clinical features overlapping with patients with ring chromosome 22. Loss of DNA in the 22q13.3 region may lead to a clinically recognizable syndrome named "22q13.3 deletion syndrome." We report a patient with a ring chromosome 22 who has hypotonia, profound mental retardation, language impairment, dysmorphic features, and behavioral disorders. To check if the critical region responsible for "22q13.3 deletion syndrome" was absent in this ring, a fluorescent in situ hybridization (FISH) analysis using a probe corresponding to the ARSA locus was performed. In our patient, only one ARSA signal could be detected, indicating that the deletion encompassed the critical 22q13.3 region. A more detailed analysis of the deletion extent then was performed using a panel of fluorescent probes located within 22q13. These experiments allowed the identification of the breakpoint between CTA-299D3 and RP5-925J7 probe, located in 22q13.32. Deletion extent could be estimated to be about 2.5 Mb, and this larger deletion may explain the severity of clinical features observed in our patient.

Identification of a mutant allele of the androgen receptor gene in a family with androgen insensitivity syndrome: detection of carriers and prenatal diagnosis.

We report the results of a molecular study of a large family segregating the complete form of the Androgen Insensitivity Syndrome (CAIS) in several family members from three generations. We identified the mutant allele by polymerase chain reaction (PCR) amplification of the short tandem repeat (CAG)n, highly polymorphic in the population, present in the first exon of the androgen receptor (AR) gene. In this family four different alleles were detected and one of these showed a perfect segregation with the disease. This study enabled us to identify the heterozygous females in this family. We think that this simple, indirect test, is also suitable for prenatal diagnosis of Morris' syndrome when the mother is heterozygous for the size of the short tandem repeat and one affected subject in the family may be studied.

Polymeric reagents with propane-1,3-dithiol functions and their precursors for supported organic syntheses

Reliable completely odorless syntheses of soluble copolymeric reagents of styrene type containing propane-1,3-dithiol functions able to convert carbonyl compounds into 1,3-dithiane derivatives and to support other useful transformations are reported together with their progenitor copolymers containing benzenesulfonate or thioacetate groups perfectly stable in open air and suitable for unlimited storage. The effectiveness of the prepared reagents as tools for polymer-supported syntheses to produce ketones by aldehyde umpolung and alkylation is tested in the conversion of benzaldehyde to phenyl n-hexyl ketone starting from copolymers with different contents of active units and molecular weights. To facilitate the adaptation of the prepared soluble copolymeric reagents to other possible applications, a table of solvents and nonsolvents is presented.

A new submicroscopic deletion that refines the 9p region for sex reversal.

Male to female sex reversal has been described in patients with deletions of chromosome 9p, and a region critical for sex reversal has been localized to p24.3, at the tip of the chromosome (TD9). It was proposed that the sex reversal may arise by haploinsufficiency for a gene localized to the minimum deletion. The 9p24.3 genes DMRT1 and DMRT2 are the favorite TD9 candidates to date, in virtue of their sequence similarity to doublesex and mab-3, sexual regulators in Drosophila and Caenorhabditis elegans, respectively. The hypothesis of sex reversal by combined haploinsufficiency for the two genes was put forward to explain the lack of mutations in either gene in XY sex-reversed females. Here we describe a XY sex-reversed patient carrying a novel 9p deletion that extends over less than 700 kb of genomic DNA. This region defines the smallest interval for sex reversal found to date. DMRT1 and DMRT2 map outside this region. Our data do not support the hypothesis of combined haploinsufficiency for DMRT1 and DMRT2. Nevertheless, DMRT1 localizes very close to the deletion breakpoint and has a pattern of expression compatible with a role in sex determination. It therefore remains a candidate gene for 9p sex reversal.

The expression pattern of a mouse doublesex-related gene is consistent with a role in gonadal differentiation.

The signal for somatic sex determination in mammals, Caenorhabditis elegans and Drosophila melanogaster is chromosomal, but the overall mechanisms do not appear to be conserved between the phyla. However it has been found quite recently that the C. elegans sex-determining gene Mab-3 contains a domain highly homologous to the Drosophila sex-determining gene doublesex (dsx) and shares a similar role. These data suggest that at least some aspects of the regulation of sex determination might be conserved. In humans, a doublesex-related gene (DMRT1) was identified at less than 30 kb from the critical region for sex reversal on chromosome 9p24 (TD9). In order to get insights into the role of DMRT1 in sex determination/differentiation, we have isolated DMRT1 mouse homologue (Dmrt1) and analysed its expression pattern. The gene is expressed in the genital ridges of both sexes during the sex-determining switch and it shows male/female dimorphism at late stages of sex differentiation.

Benzylamine-related compounds stimulate rat vas deferens neurotransmission and potentiate memory in the mouse acting as potassium channel blockers.

In stimulated rat vas deferens, the new compound 2, 6-dibutylbenzylamine (B25) and some related benzylamines, first potentiated then completely inhibited electrically-induced twitch response, showing the biphasic effect previously observed in unstimulated preparations. To verify if this effect could be referred to as a modulation of potassium channels the activity of some benzylamines, KCl, tetraetylammonium (TEA), BaCl(2), 4-aminopyridine (4-AP), glibenclamide (GLI), charibdotoxin (ChTX) and apamin (APA) has been compared. While KCl and benzylamine-related derivatives induced biphasic effects, TEA, 4-AP, BaCl(2), GLI stimulated but were unable to inhibit the twitches. The pretreatment with stimulating concentrations of TEA, 4-AP, GLI, APA or ChTX and B25, as reference compound in the benzylamine series, dose-dependently reduced the stimulatory effect of KCl but were unable to modify the inhibitory effect induced by this ion. Both KCl and B25 potentiated each others own inhibitory effect suggesting that, unlike other potassium channel blockers, they could modulate in an opposite way voltage-dependent potassium channels in order to facilitate and then depress neurotransmission. In other experiments, benzylamines, KCl, TEA, 4-AP and GLI reverted the inhibitory effect of cromakalim and omega-conotoxin GVIA (omega-CTX). This effect further supports a common mechanism of action (potassium channel blockade) probably inducing the opening of Ca(2+)channels different from N or L in the preparation. Finally, the prevention of minoxidil-induced amnesia in the mouse by B25 and related benzylamines, comparable to the same effect shown by TEA and 4-AP, indicates that these compounds are endowed with potential pharmacological activity in the CNS as well.

The mechanism of inhibition of benzylamine oxidase by 3,5-diethoxy-4-aminomethylpyridine (B24).

B24, 3,5-diethoxy-4-aminomethylpyridine, is a specific inhibitor of the semicarbazide-sensitive amine oxidase with high affinity for benzylamine (BnNH2.SSAO). It is a site-directed inhibitor of pig plasma benzylamine oxidase (BAO) with an affinity for the enzyme much higher than that for benzylamine. B24 inhibition is dependent on the molar ratio B24/BAO because the inhibitor reacts mole to mole with the enzyme and benzylamine appears to be ineffective in removing the inhibitor from the adduct [EI]. B24 is a weak substrate of BAO and for this reason the degree of inhibition (when the molar ratio B24/BAO is lower than 1) decreases with the incubation time as well as with the preincubation time. This decrease is dependent on the gradual release of free enzyme which reacts with the substrate, giving [ES] without any interfering free B24. When the B24/BAO molar ratio is higher than 1, the free enzyme released by the oxidative deamination of B24 reacts with the substrate, but the free B24 present competitively inhibits the formation of [ES] and the affinity of benzylamine is therefore reduced. This is the reason why B24, in the kinetic experiments in which the inhibitor is not pre-incubated with the enzyme, may appear to be a competitive inhibitor or a mixed inhibitor, mainly competitive. When B24 is preincubated with the enzyme and the initial rate of benzylamine oxidation is measured, it appears as a non-competitive inhibitor becoming a mixed one only when the B24/BAO molar ratio is high and the incubation time is long.

Identification by gas chromatography-mass spectrometry of an adduct between pure pig plasma benzylamine oxidase and the inhibitor 3,5-diethoxy-4-aminomethylpyridine.

3,5-Diethoxy-4-aminomethylpyridine (B24) interacts with pure pig plasma benzylamine oxidase (BAO), giving a Schiff base with the carbonyl active site. This Schiff base was reduced, isolated by chemical hydrolysis of the enzyme, purified by HPLC and identified by gas chromatography-mass spectrometry (GC-MS) after derivatization. The isolated B24 adduct had the same absorption spectrum, retention time on HPLC and GC and the same mass spectrum as B24-pyridoxamine. B24, which is a reversible enzyme inhibitor, is also a weak substrate and competes with benzylamine, which is the best substrate, for the active site. These results further indicate the presence of pyridoxal-phosphate covalently linked to the pig plasma benzylamine oxidase and involved in the active site of this enzyme.

[Osteoarthritis caused by Brucella melitensis: isolation of the microorganism from the synovial fluid]. / Osteoartrite da Brucella melitensis: isolamento del germe nel liquido sinoviale.

Brucellosis is an unusual disease in childhood but the organ manifestations are even more unusual. The Authors describe an osteoarthritis caused by Brucella melitensis, localized at the tarsal scaphoid in a three years old Calabrian child.

Reaction of pig plasma benzylamine oxidase with beta-aminopropionitrile.

Beta-aminopropionitrile (BAPN) is an inhibitor of pig plasma benzylamine oxidase. BAPN is oxidized by benzylamine oxidase. Inhibition develops in a time-dependent fashion upon incubation of BAPN with the enzyme in the absence of substrate. The product of oxidation of BAPN by benzylamine oxidase, cyanacetaldehyde, was identified and prepared by synthesis. It is an irreversible inhibitor of the enzyme.