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Biomedical subjects

L Pavone

Publications and source records attributed to L Pavone.

At least 37 records · Page 2Linked to original sources

Autism and celiac disease: failure to validate the hypothesis that a link might exist.

Autism is a heterogeneous condition and the possible pathogenic role of several different factors has been postulated. Association between celiac disease and neurological manifestations such as drug resistant epilepsy and cerebral calcifications is well known. Some authors in the past also reported the existence of a linkage with autism. On the basis of these observations, we have evaluated 120 patients with celiac disease diagnosed at the Pediatric Clinic of the University of Catania, Italy, in order to identify behavioral problems and autistic features: there were 20 controls for this part of the study. At the same time, AGA and AEMAb were assayed in 11 patients with infantile autism and 11 age- and sex-matched controls. No celiac case was detected among the group of autistic patients and, although two of them had slightly increased levels of AGA IgG and AEMAb, subsequent antibodies determinations and jejunal biopsies gave normal results. Moreover none of the celiac patients had a positive DSM-III-R test for infantile autism.

Autistic Disorder↗

Another "new" form, the palagonia type of acrofacial dysostosis in a Sicilian family.

We described another previously apparently unreported form of acrofacial dysostosis (AFD) from Sicily, residing, coincidentally in the same small village as that with the recently delineated Catania AFD. In contra-distinction to the latter, the 4 patients with the Palagonia form of AFD are of normal intelligence, and instead of extensive caries have oligodontia (4), short stature (3), frizzy hair (pili torti) with aplasia cutis verticis (1), mild cutaneous syndactyly of digits 2-5 (4), attenuation of the 4th metacarpals (3/3), unilaterally cleft lip (1), and some vertebral anomalies such as a large atlas (1), mild scoliosis (1), small odontoid process, spina bifida occulta at S1 (1). Casually, this would appear to be an iceberg dominant disorder, with the proposita most severely affected. This could be an X-linked dominant, but more likely an autosomal dominant trait.

Abnormalities, Multiple↗

Identification and analysis of mutations in the Wilson disease gene (ATP7B): population frequencies, genotype-phenotype correlation, and functional analyses.

Wilson disease (WD) is an autosomal recessive disorder characterized by toxic accumulation of copper in the liver and subsequently in the brain and other organs. On the basis of sequence homology to known genes, the WD gene (ATP7B) appears to be a copper-transporting P-type ATPase. A search for ATP7B mutations in WD patients from five population samples, including 109 North American patients, revealed 27 distinct mutations, 18 of which are novel. A composite of published findings shows missense mutations in all exons-except in exons 1-5, which encode the six copper-binding motifs, and in exon 21, which spans the carboxy-terminus and the poly(A) tail. Over one-half of all WD mutations occur only rarely in any population sample. A splice-site mutation in exon 12 accounts for 3% of the WD mutations in our sample and produces an in-frame, 39-bp insertion in mRNA of patients homozygous, but not heterozygous, for the mutation. The most common WD mutation (His1069Glu) was represented in approximately 38% of all the WD chromosomes from the North American, Russian, and Swedish samples. In several population cohorts, this mutation deviated from Hardy-Weinberg equilibrium, with an overrepresentation of homozygotes. We did not find a significant correlation between His1069Glu homozygosity and several clinical indices, including age of onset, clinical manifestation, ceruloplasmin activity, hepatic copper levels, and the presence of Kayser-Fleischer rings. Finally, lymphoblast cell lines from individuals homozygous for His1069Glu and 4 other mutations all demonstrated significantly decreased copper-stimulated ATPase activity.

Adenosine Triphosphatases↗

Tuberous sclerosis complex: neonatal deaths in three of four children of consanguineous, non-expressing parents.

We describe here four sibs, born to consanguineous, healthy, asymptomatic parents. Three of these infants had a rapidly fatal course in the neonatal period; death was attributed to congestive heart failure with radiographic evidence of cardiomegaly in all of them. Necropsy was done in only one of them and showed the typical findings of tuberous sclerosis complex (TSC) in the central nervous system (CNS), kidneys, heart, and liver. The fourth sib, currently 2 years old, also has typical signs of TSC, namely hypomelanotic skin macules and calcified subependymal nodules. Both parents and a living maternal grandmother had appropriate examination, which included skin inspection under Wood's lamp, dental examination, fundoscopy, echocardiography, abdominal and renal ultrasound, and head CT and MRI scans, and no signs of TSC were found in either parent or in the only living grandmother. By history alone there is no other relative with signs or symptoms suggestive of TSC. Linkage analysis and loss of heterozygosity (LOH) investigations on a variety of lesions obtained from postmortem and tissue or blood specimens from all available family members studied failed to identify a microdeletion in the chromosomal regions where TSC genes are located. It is very unusual that in a single TSC family there were three consecutive neonatal deaths, and very likely that all had cardiac rhabdomyomas. Moreover, to the best of our knowledge, there are no previous reports of TSC families with more than one affected sib, unusually severe manifestations of the disease, and completely normal, consanguineous parents.

Child, Preschool↗

Clinical and neuroradiological findings in classic infantile and late-onset globoid-cell leukodystrophy (Krabbe disease).

In the present study the clinical course and imaging of early and late-onset forms of Krabbe disease are analyzed. We report on 11 patients with a biochemical diagnosis of galactosyl ceramide beta-galactoside deficiency. Two presented as the classic infantile form and died within the second year of life. In 9 children the first clinical signs, such as gait difficulties and visual failure, started after age 2 years. All these patients developed slow regression of motor and mental capacities, and most of them died within their first decade. In patients of both groups computed tomography (CT) and magnetic resonance imaging (MRI) were performed. In the late-onset form, hypodensities of the central white matter and pyramidal tracts were the leading radiological signs, whereas in the early-onset form, hyperdensities and cerebellar white matter lesions were also detected. From our results it becomes clear that variability of Krabbe disease refers not only to clinical manifestation but also to CT and MRI findings. Better knowledge of phenotypic and radiological diversity will help to understand the pathogenesis of the disease.

Age of Onset↗

Molecular basis of phenotypic heterogeneity in siblings with spinal muscular atrophy.

We report on a family with childhood-onset spinal muscular atrophy with intrafamilial phenotypic variation. Typical of a large majority of such patients, both the child with spinal muscular atrophy type I and the child with type II were missing both copies of the survival motor neuron telomeric gene (SMN(T)). The more severely affected child, however, showed genotypic evidence consistent with the de novo loss of DNA sequence in addition to that inherited by both affected children. These data suggest that the intrafamilial phenotypic variation in this family results from a new mutation event in the more severely affected child. Examples of intrafamilial phenotypic variability are quite rare, but some reports exist in the spinal muscular atrophy literature. We present evidence that one explanation for this phenomenon is the occurrence of de novo deletion events at the highly unstable disease locus.

Alleles↗

Neurological complications in hospitalized patients with pertussis: a 15-year Sicilian experience.

Three hundred forty patients were diagnosed with pertussis infection at the Pediatric Clinic of the University of Catania, Sicily during the period 1979-1994. None of these patients had been previously vaccinated. Fourteen developed neurological complications at some point in their course, which took the form of seizures (both febrile and afebrile) and, in some cases, encephalopathy. Serious permanent neurological sequelae were not observed in this series of patients though they had pertussis severe enough to require hospitalization.

Brain Diseases↗

Olivopontocerebellar atrophy leading to recognition of carbohydrate-deficient glycoprotein syndrome type I.

The carbohydrate-deficient glycoprotein (CDG) syndromes are a group of genetic multisystem disorders with invariable involvement of the nervous system including severe olivopontocerebellar atrophy. We report two sets of sibs in whom the diagnosis of CDG syndrome type 1 was recognized at an older age because of marked olivopontocerebellar atrophy seen on MRI. Previous CT findings were interpreted as showing Dandy-Walker malformation. Three of the patients are also among the oldest reported with this syndrome.

Adult↗

PAH deficiency in Italy: correlation of genotype with phenotype in the Sicilian population.

The results of the neonatal screening for phenylalanine hydroxylase (PAH) deficiency in Sicily show that its incidence is higher than previously reported for mainland Italians and that non-PKU HPA is in excess of classical and mild PKU. The latter finding suggests that a high number of non-PKU HPA mutations would occur in the Sicilian population compared to populations with an inverted PKU/non-PKU HPA ratio. Previous studies have identified 40 mutations accounting for the majority (98%) of mutant alleles underlying PAH deficiency in Sicily. In order to study the molecular basis of the distribution of PAH deficiency phenotypes in the Sicilian population, we have correlated 31 of those mutations with clinical and metabolic phenotypes in 12 mentally retarded patients, 14 treated patients with classic or mild PKU, and 13 subjects presenting the non-PKU HPA phenotype. The present study proposes a tentative classification for a large number (26) of PAH gene mutations which may represent an additional tool for establishing a differential diagnosis for PAH deficiency in the Sicilian population.

Amino Acid Metabolism, Inborn Errors↗

Acute palsy of the recurrent laryngeal nerve complicating Epstein-Barr virus infection.

We report an 11-year-old boy with active Epstein-Barr virus (EBV) infection who developed acute aphonia and had signs and symptoms of recurrent laryngeal nerve palsy. The association of isolated recurrent laryngeal nerve palsy and EBV infection has not previously been reported. This case report expands the spectrum of neurologic complications of EBV infection, and suggests that infectious mononucleosis should be considered in the differential diagnosis of acute aphonia in children.

Antibodies, Viral↗

Routine clinical application of the FRAXA Pfu PCR assay: limits and utility.

Fragile X genotype is characterized by the excessive amplification of an unstable region of DNA: a trinucleotide repeat CGG of variable copy number present in the FRAXA locus. Methods based on polymerase chain reaction (PCR) amplification of the CGG repeat region could facilitate the development of a rapid screening assay. Unfortunately, amplification across CGG repeats can be inefficient and unreliable due to their 100% G + C base composition. The utility of the exonuclease-deficient Pfu polymerase for amplification and detection of the CGG repeats at the FRAXA locus has been reported. In the present study we analysed the utility of a Pfu PCR assay as a rapid initial screening method to rule out a diagnosis of fragile X syndrome in males with mental retardation. Affected males did not show any amplification products or a smear of amplification products between 350 and 550 bp. Only 10% of affected male samples did not show any amplification products, while the vast majority showed the amplification smear. The amplification smears represent a serious drawback of the method, since they cannot be distinguished from the amplification products of normal samples after separation in 1% agarose gel. Several modifications of the PCR conditions were attempted to eliminate this problem, but none was appropriate for clinical applications. However, the problem was easily solved by using a higher resolution electrophoretic system that allows a clear distinction of normal bands from pathological smears. We tested the specificity of the Pfu PCR assay, followed by an improved MetaPhor gel electrophoretic separation of PCR products, on 50 samples from normal males and 24 samples form affected males. The results showed that this method is a rapid, sensitive and specific assay for the exclusion of fragile X syndrome diagnosis in mentally retarded males.

DNA-Directed DNA Polymerase↗

Involvement of the white matter in hypomelanosis of Ito (incontinentia pigmenti achromiens).

We report our clinical and neuroradiologic findings in 13 patients affected by hypomelanosis of Ito. Seven patients were boys and six were girls; their ages ranged from 11 months to 16 years. Neurologic signs were present in all but two cases, and they consisted of language disabilities, seizures, hypotonia, mental retardation, and autistic behavior. MRI was performed in all patients. We observed anomalies of the white matter in seven of the 13 patients; all but one of these seven had neurologic signs that included seizures, hypotonia, language disabilities, and mental retardation. The abnormal signals in the white matter were mostly located in the parietal periventricular and subcortical regions of both hemispheres. Moreover, we found asymmetry of the cerebral hemispheres in one of our 13 patients and atrophy of the cerebellar vermis in another patient, with no involvement of the white matter in either. In the remaining four of the 13 patients results of MRI appeared normal. There was a relationship between the anomalies in the central nervous system at MRI, as a whole, and the neurologic manifestations, even though two patients with apparently normal images on MRI had partial and generalized tonic clonic seizures, respectively. A correlation was also found between white matter anomalies and neurologic signs; extended and deep changes in white matter images were associated with more severe neurologic abnormalities and delayed language milestones appeared to be a constant finding in this group of patients. These anomalies of the white matter, which did not progress over time, resembled those seen in other neurocutaneous syndromes. The hypothesis is presented that underlying disarray of cortical lamination or neuronal loss with subsequent wallerian degeneration and altered or delayed myelination could be the cause of the abnormal findings on MRI.

Adolescent↗

Hypertrichosis, coarse face, brachydactyly, obesity and mental retardation.

A 17-year-old boy with a complex array of dysmorphic features including generalized hypertrichosis of the terminal hair, coarse face, short stature, obesity, brachydactyly with broad proximal phalanges, small and dyschromic nails, and mental retardation is reported. Virilizing endocrinopathies, obesity/mental retardation syndromes, and conditions with hirsutism associated with small or absent nails are discussed and particular emphasis is given to the syndrome of "generalized hypertrichosis terminalis and gingival hyperplasia" which shares some features with the patient.

Abnormalities, Multiple↗

Haemostatic studies in carbohydrate-deficient glycoprotein syndrome type I.

CDG syndrome (CDGS) type I is the most frequent form of a group of metabolic disorders characterised by a defect of the carbohydrate moiety of glycoproteins. A large number of plasma glycoproteins, including clotting factors and inhibitors, are decreased and stroke-like episodes have been described in about half of the reported patients. We studied blood coagulation factors, inhibitors and D-dimer plasma levels in four subjects, aged 12-23 years, with CDGS type I. Factors VIII, XI, antithrombin III activity, antigen plasma levels of antithrombin III, free protein S and protein C were decreased whereas protein C as activity was normal. In addition two patients had reduction of factors II, V, VII, IX, X reflecting the phenotypic heterogeneity associated with CDGS type I. D-dimer plasma concentrations were elevated in all subjects. The hypercoagulable state as consequence of the combined deficiencies of coagulation inhibitors could contribute to the stroke-like phenomena in CDGS type I.

Adolescent↗

Autosomal-recessive microcephaly in two siblings, one with normal IQ and both with protruding mandible, small ears, and curved nose.

We report on 2 sibs with severe microcephaly and unusual associated manifestations. The brother has borderline/normal intelligence, episodic seizures, clumsiness, and the more severe of facial manifestations; the sister has normal IQ and neither seizures nor behavior abnormalities. Small ears, markedly protruding midface, curved nose, and severe retrognathia are present in both sibs. We postulate that our patients have a "new" form of AR microcephaly, since normal intelligence is not found, nor are the associate findings as pronounced, as in other, more common forms of AR microcephaly (i.e., "microcephalia vera").

Abnormalities, Multiple↗