Orazio Gabrielli

Prevalence and clinical picture of celiac disease in italian down syndrome patients: a multicenter study.

Background A multicenter research study of Down syndrome patients was carried out to estimate the prevalence of celiac disease in patients with Down syndrome and to show clinical characteristics and laboratory data of Down syndrome patients. Methods The authors studied 1,202 Down syndrome patients. Fifty-five celiac disease patients (group 1) were compared with 55 immunoglobulin A antigliadin–positive antiendomysium antibodies–negative patients (group 2) and with 57 immunoglobulin A antigliadin–negative antiendomysium antibodies–negative patients (group 3). Results Celiac disease was diagnosed in 55 of 1,202 Down syndrome patients (4.6%). In group 1, weight and height percentiles were shifted to the left, whereas these parameters were normally distributed in groups 2 and 3. In celiac patients, diarrhea, vomiting, failure to thrive, anorexia, constipation, and abdominal distension were higher than in the other two groups. Low levels of hemoglobinemia, serum iron, and calcium were observed more frequently in group 1. The diagnosis of celiac disease was made after a mean period of 3.8 years from the initiation of symptoms. Sixty-nine percent of patients showed a classic presentation, 11% had atypical symptoms, and 20% had silent celiac disease. Autoimmune disorders were more frequent (30.9%) in group 1 than in the other two groups examined (15%;P < 0.05). Conclusions This study reconfirms a high prevalence of celiac disease in Down syndrome. However, the diagnostic delay, the detection of atypical symptoms or silent form in one third of the cases, and the increased incidence of autoimmune disorders suggest the need for the screening of celiac disease in all Down syndrome patients.

Preliminary study of breastfeeding and bacterial adhesion to uroepithelial cells

The oligosaccharide content of breast-milk and urine from ten nursing mothers and their babies, collected 30 days after delivery, was analysed by thin-layer and high-performance liquid chromatography. Each womans milk and urinary oligosaccharide profiles were very similar, and the pattern of oligosaccharides excreted by her infant was also strongly correlated with that of her milk. The babies excreted 300-500 mg/day oligosaccharides and the mothers 500-800 mg/day. The effect of oligosaccharide fractions from a 500 ml pool of colostrum on bacterial adhesion to uroepithelial cells was tested on a strain of Escherichia coli isolated from an infant with urinary tract infection. The high-molecular-weight sialylated oligosaccharides had no effect but neutral oligosaccharides caused inhibition of bacterial adhesion which rose as the size of the oligosaccharides decreased. These findings suggest that breastfeeding may have a preventive effect on urinary tract infection in both mother and infant.

Preterm Milk Oligosaccharides During the First Month of Lactation

OBJECTIVE: Oligosaccharides represent one of the main components of human milk, and they have been assigned important biological functions for newborns. Qualitatively and quantitatively, their presence in milk is strictly related to the expression of the mothers Se and/or Le genes, on the basis of which 4 different milk groups have been described. The aim of the study was to provide new data on the oligosaccharide composition of preterm milk in relation to the 4 groups. METHODS: High-pH anion-exchange chromatography was used to quantify levels of 23 oligosaccharides and lactose in 252 milk samples collected from 63 mothers during the first month of lactation and to identify the 4 milk groups. RESULTS: Substantial differences in oligosaccharide contents were found within the groups and were strictly related to the presence or absence of specific fucosyl-oligosaccharides. The highest concentration was found in group 1 (>20 g/L), the lowest level was found in group 4 (∼10 g/L), and intermediate values were observed in groups 2 and 3. No statistically significant differences in lactose concentrations were observed among the groups. CONCLUSIONS: Our data confirm lower lactose concentrations in preterm milk, compared with term milk, and they provide the first detailed characterization of oligosaccharides in preterm milk, demonstrating important differences in oligosaccharide contents in the 4 groups. These differences might exert an influence on several biological functions that are particularly important for preterm infants and currently are attributed to milk oligosaccharides.

Enzyme-Replacement Therapy in a 5-Month-Old Boy With Attenuated Presymptomatic MPS I: 5-Year Follow-up

Mucopolysaccharidosis type I (MPS I) is a progressive and multisystemic disease, even in its attenuated Hurler-Scheie and Scheie forms. Clinical trials of enzyme-replacement therapy in MPS I have shown clinical benefit in patients with considerable preexisting disease, but no data exist on the effect of beginning enzyme replacement before the onset of significant clinical signs of disease. Here we present the 5-year follow-up of a boy with attenuated MPS I who had laronidase therapy initiated at the age of 5 months and compare his clinical course to that of his older sister, who began treatment at 5 years of age after she had developed typical signs of MPS I. After 5 years of treatment, the younger sibling has not developed any clinical manifestations of MPS I except for mild corneal clouding. In contrast, although many of the older siblings clinical features have improved after 5 years of treatment, her dysostosis multiplex, cardiac valve involvement, and corneal clouding, although stabilized, have persisted. We suggest that early treatment of attenuated MPS I may significantly delay or prevent the onset of the major clinical signs, substantially modifying the natural history of the disease.

Mutation spectrum of MLL2 in a cohort of kabuki syndrome patients

BackgroundKabuki syndrome (Niikawa-Kuroki syndrome) is a rare, multiple congenital anomalies/mental retardation syndrome characterized by a peculiar face, short stature, skeletal, visceral and dermatoglyphic abnormalities, cardiac anomalies, and immunological defects. Recently mutations in the histone methyl transferase MLL2 gene have been identified as its underlying cause.MethodsGenomic DNAs were extracted from 62 index patients clinically diagnosed as affected by Kabuki syndrome. Sanger sequencing was performed to analyze the whole coding region of the MLL2 gene including intron-exon junctions. The putative causal and possible functional effect of each nucleotide variant identified was estimated by in silico prediction tools.ResultsWe identified 45 patients with MLL2 nucleotide variants. 38 out of the 42 variants were never described before. Consistently with previous reports, the majority are nonsense or frameshift mutations predicted to generate a truncated polypeptide. We also identified 3 indel, 7 missense and 3 splice site.ConclusionsThis study emphasizes the relevance of mutational screening of the MLL2 gene among patients diagnosed with Kabuki syndrome. The identification of a large spectrum of MLL2 mutations possibly offers the opportunity to improve the actual knowledge on the clinical basis of this multiple congenital anomalies/mental retardation syndrome, design functional studies to understand the molecular mechanisms underlying this disease, establish genotype-phenotype correlations and improve clinical management.

SOS1 mutations in Noonan syndrome: molecular spectrum, structural insights on pathogenic effects, and genotype–phenotype correlations†

Noonan syndrome (NS) is among the most common nonchromosomal disorders affecting development and growth. NS is caused by aberrant RAS‐MAPK signaling and is genetically heterogeneous, which explains, in part, the marked clinical variability documented for this Mendelian trait. Recently, we and others identified SOS1 as a major gene underlying NS. Here, we explored further the spectrum of SOS1 mutations and their associated phenotypic features. Mutation scanning of the entire SOS1 coding sequence allowed the identification of 33 different variants deemed to be of pathological significance, including 16 novel missense changes and in‐frame indels. Various mutation clusters destabilizing or altering orientation of regions of the protein predicted to contribute structurally to the maintenance of autoinhibition were identified. Two previously unappreciated clusters predicted to enhance SOS1s recruitment to the plasma membrane, thus promoting a spatial reorientation of domains contributing to inhibition, were also recognized. Genotype–phenotype analysis confirmed our previous observations, establishing a high frequency of ectodermal anomalies and a low prevalence of cognitive impairment and reduced growth. Finally, mutation analysis performed on cohorts of individuals with nonsyndromic pulmonic stenosis, atrial septal defects, and ventricular septal defects excluded a major contribution of germline SOS1 lesions to the isolated occurrence of these cardiac anomalies. Hum Mutat 32:760–772, 2011.

Two novel and one known mutation of the TGFBR2 gene in Marfan syndrome not associated with FBN1 gene defects

TGF-β-receptor 2 (TGFBR2) gene defects have been recently associated with Marfan syndrome (MFS) with prominent cardio-skeletal phenotype in patients with negative fibrillin-1 (FBN1) gene screening. Four mutations have been identified to date in five unrelated families. We screened TGFBR2 gene by direct automated sequencing in two adult patients diagnosed with MFS according to Ghent criteria, and in one girl clinically suspected as affected on the basis of a major cardiovascular criterion and skeletal involvement, all proven not to carry mutations in the exon–intron boundaries of FBN1 gene. We identified two novel and one known TGFBR2 gene mutations in the three unrelated probands. The D446N was identified in a 4-year-old girl with de novo disease characterized by severe cardiovascular disease and skeletal involvement. The M425V and R460H mutations were identified in two familial, autosomal dominant MFSs, both characterized by major cardio-skeletal signs and absence of major ocular signs. The mutation R460H has been recently reported in a family with thoracic aortic aneurysms and dissection. The three mutations are absent in 192 controls and affect evolutionarily conserved residues of the serine/threonine kinase domain (exon 5). Our data support the recently reported association between TGFBR2 gene and MFS without major ocular signs (MFS2). The number of genotyped cases however is too low to confirm that major ocular signs are characteristically absent in MFS2. Accordingly, all patients proven or suspected to be affected by MFS with negative FBN1 gene screening could benefit from rapid investigation of the TGFBR2 gene.

Comprehensive Clinical and Molecular Assessment of 32 Probands With Congenital Contractural Arachnodactyly: Report of 14 Novel Mutations and Review of the Literature

Beals‐Hecht syndrome or congenital contractural arachnodactyly (CCA) is a rare, autosomal dominant connective tissue disorder characterized by crumpled ears, arachnodactyly, contractures, and scoliosis. Recent reports also mention aortic root dilatation, a finding previously thought to differentiate the condition from Marfan syndrome (MFS). In many cases, the condition is caused by mutations in the fibrillin 2 gene (FBN2) with 26 mutations reported so far, all located in the middle region of the gene (exons 23–34). We directly sequenced the entire FBN2 gene in 32 probands clinically diagnosed with CCA. In 14 probands, we found 13 new and one previously described FBN2 mutation including a mutation in exon 17, expanding the region in which FBN2 mutations occur in CCA. Review of the literature showed that the phenotype of the FBN2 positive patients was comparable to all previously published FBN2‐positive patients. In our FBN2‐positive patients, cardiovascular involvement included mitral valve prolapse in two adult patients and aortic root enlargement in three patients. Whereas the dilatation regressed in one proband, it remained marked in a child proband (z‐score: 4.09) and his father (z‐score: 2.94), warranting echocardiographic follow‐up. We confirm paradoxical patellar laxity and report keratoconus, shoulder muscle hypoplasia, and pyeloureteral junction stenosis as new features. In addition, we illustrate large intrafamilial variability. Finally, the FBN2‐negative patients in this cohort were clinically indistinguishable from all published FBN2‐positive patients harboring a FBN2 mutation, suggesting locus heterogeneity. Hum Mutat 0, 1–8, 2008.

Correlation between cerebral MRI abnormalities and mental retardation in patients with mucopolysaccharidoses.

Mucopolysaccharidoses (MPSs) are a group of inherited disorders due to lysosomal enzyme deficiencies which lead to multi‐organ accumulation of glycosaminoglycans. Some forms of MPS disorders are characterized by various degrees of mental retardation. Magnetic Resonance Imaging (MRI) is the primary imaging technique to detect CNS alterations. The aim of this study is to evaluate the correlation between white matter (WM) alterations and the presence of mental retardation. We analyzed 20 patients with different forms of MPSs, 11 with mental retardation and 9 with a normal cognitive function; all of them underwent brain MRI and received a score on the basis of the alterations (WM alterations; perivascular, subarachnoid, and ventricular space enlargement; abnormalities of the basal ganglia, of the corpus callosum and of the atlanto‐axial joint). All patients with mental retardation presented severe WM alterations, while only five out of the nine subjects without mental retardation showed certainly WM abnormalities. As far as the other cerebral abnormalities are concerned, no difference between the two groups has been found. These data seem to show that there is a significant correlation between the presence of WM alterations and mental retardation.

IDUA mutational profiling of a cohort of 102 European patients with mucopolysaccharidosis type I: identification and characterization of 35 novel α-L-iduronidase (IDUA) alleles

Mutational analysis of the IDUA gene was performed in a cohort of 102 European patients with mucopolysaccharidosis type I. A total of 54 distinct mutant IDUA alleles were identified, 34 of which were novel including 12 missense mutations, 2 nonsense mutations, 12 splicing mutations, 5 micro‐deletions, 1 micro‐duplication 1 translational initiation site mutation, and 1 ‘no‐stop’ change (p.X654RextX62). Evidence for the pathological significance of all novel mutations identified was sought by means of a range of methodological approaches, including the assessment of evolutionary conservation, RT‐PCR/in vitro splicing analysis, MutPred analysis and visual inspection of the 3D‐model of the IDUA protein. Taken together, these data not only demonstrate the remarkable mutational heterogeneity characterizing type 1 mucopolysaccharidosis but also illustrate our increasing ability to make deductions pertaining to the genotype‐phenotype relationship in disorders manifesting a high degree of allelic heterogeneity.