Different expression of the myotonin protein kinase gene in discrete areas of human brain.

We have examined the myotonin protein kinase (MT-PK) gene expression in different human brain areas. Four different spliced forms, comprising exons 13 and 14, were identified and characterized. One form (MYOT-A), lacking the entire exon 13, had not been detected in other studies and it is likely to be a brain-specific transcript.

Survival motor neuron gene transcript analysis in muscles from spinal muscular atrophy patients.

We have identified and characterized four different mRNA isoforms of the survival motor neuron (SMN) gene from skeletal muscle of 9 SMA patients and 15 unaffected controls. These isoforms appear to be generated by combinatorial splicing of both exons 5 and 7 of the SMN telomeric and centromeric gene copies. The full-size and the truncated SMN-1b isoforms of the telomeric SMN copy are significantly reduced in muscle of SMA patients, irrespective of the disease types.

Postzygotic instability of the myotonic dystrophy p[AGC] in repeat supported by larger expansions in muscle and reduced amplifications in sperm.

We have analysed the [AGC] expansion in leucocytes, muscle and sperm from 17 individuals affected by myotonic dystrophy (DM). Skeletal muscle showed a larger repeat number than leucocytes in the same patient. A similar degree of expansion was detected in differently affected muscles of a single patient.

[Transesophageal echocardiography in patients with atrial fibrillation, candidates for cardioversion: usefulness and limitations].

Background: Thromboembolic complications after electrical cardioversion (CV) of atrial fibrillation (AF) have been attributed to the dislodgment of preexistent left atrial thrombus during the resumption of atrial contraction. Transesophageal echocardiography (TEE) has been used to identify patients without thrombus, who potentially could undergo CV without anticoagulation. However, embolic events after CV in patients without evidence of thrombus on TEE have recently been reported.

Identification of multiple transcribed sequences from the spinal muscular atrophy region of human chromosome 5.

We report the isolation and characterization of novel expressed sequences from the spinal muscular atrophy (SMA) region on human chromosome 5q13. Based on the sequence homology studies these cDNAs were grouped in four classes, one of which shows extensive homologies with the beta-glucuronidase (BG) gene, differing in exon arrangement. The other cDNAs do not show any strong homology with known DNA sequences.

Molecules with neurotrophic effects on the human developing mesencephalic dopaminergic neurons.

Parkinson's disease (PD) is characterized by the degeneration of the mesencephalic dopaminergic (mesDA) neurons innervating the striatum. Neurotrophic factor(s) that prevents the degeneration and increases the functional activity of the remaining mesDA neurons are of substantial clinical interest. The origin and development of mesDA neurons were characterized in the human mesencephalon from 5.

NGF-response of EGF-dependent progenitor cells obtained from human sympathetic ganglia.

Signalling molecules are thought to play a significant role in determining the fate of neural crest progenitor cells. The human sympathetic chain was identified at 6.5, 7.

Isolation of a new gene in the Friedreich ataxia candidate region on human chromosome 9 by cDNA direct selection.

The Friedreich ataxia (FRDA) locus is localized on chromosome 9q13 in an interval less than 1 Mb between markers D9S202/FR1 and FR5. We cloned the FRDA candidate region in YACs, and we started a systematic search for transcripts in this region using the cDNA selection approach. Several overlapping cDNA clones mapping near the telomeric end of the FRDA minimum genetic region were isolated.

[Paradoxical embolism in a patient with aneurysm of the interatrial septum].

We report a case of pulmonary embolism complicated by paradoxical cerebral embolism in a patient with atrial septal aneurysm and patent foramen ovale. The patient was a 65-year-old obese woman, admitted because of sudden development of right-sided hemiplegia and dysarthria. In the few days before hospitalization she noted painful edema of the right leg and suffered from increasing dyspnea.

Human elongation factor EF-1 beta: cloning and characterization of the EF1 beta 5a gene and assignment of EF-1 beta isoforms to chromosomes 2,5,15 and X.

We report here the isolation and characterization of a novel human elongation factor-1 beta (EF-1 beta) gene by cDNA selection from YAC mapping on chromosome 5q12-q14. This gene is specifically transcribed in fetal brain and in skeletal muscle and is characterized by a complete sequence homology with previously described EF-1 beta cDNAs. We also assigned the loci for three other EF-1 beta isoforms, to human chromosomes 2, 15 and X.

The myotonic dystrophy gene.

The myotonic dystrophy gene codes for a protein kinase and contains a repeated trinucleotide motif (adenine-guanine-cytosine [AGC]) in its transcribed sequence. The repeat is polymorphic in the general population, varying in size from five to 37 AGC units in normal alleles. Myotonic dystrophy patients show expansions of the repeated sequence from over 50 elements up to several thousand units.

(CTG)n triplet mutation and phenotype manifestations in myotonic dystrophy patients.

A genotype-phenotype study based on the primary clinical features of adult myotonic dystrophy (DM) included 116 patients from 62 Italian pedigrees. A significant correlation between clinical severity and the number of repeats at the 3' untranslated region of the myotonin-protein kinase gene (MT-PK) was found. These results suggest that the CTG amplification is directly related to the myotonic dystrophy phenotype and provide important information on morbidity and prognosis in this disease.

[Cor triatriatum associated with inter-atrial defect: diagnosis by transesophageal echocardiography].

Cor triatriatum (CT) is a rare malformation consisting of a fibromuscolar membrane that subdivides the left atrium in a postero-superior (or accessory) chamber and an antero-inferior chamber (true left atrium, containing the left atrial appendage). In its classic form, the accessory chamber receives the pulmonary veins and communication with the left atrium is accomplished by way of one or more fenestrations in the membrane. The malformation is usually isolated, but in about one in four patients is associated with other congenital defects of a complex nature.

Relationship between parental trinucleotide GCT repeat length and severity of myotonic dystrophy in offspring.

Objective: To assess the relationship between the GCT repeat number in the myotonic dystrophy gene and the clinical phenotype and examine its predictive utility in prenatal testing.

Design: DNA from patients was examined for the length of the myotonic dystrophy GCT repeat region, using both Southern blot analysis and polymerase chain reaction. The results were compared with the clinical onset of disease, as well as with pregnancy outcomes.

Decreased expression of myotonin-protein kinase messenger RNA and protein in adult form of myotonic dystrophy.

The myotonic dystrophy mutation has recently been identified; however, the molecular mechanism of the disease is still unknown. The sequence of the myotonin-protein kinase gene was determined, and messenger RNA spliced forms were identified in various tissues. Antisera were developed for analytical studies.

Failure in detecting mRNA transcripts from the mutated allele in myotonic dystrophy muscle.

The expression of myotonin-protein kinase (MT-PK) gene was studied in myotonic dystrophy (DM) muscle and normal controls using a polymerase chain reaction protocol to analyse the 3' intragenic p(CTG) polymorphism. Unaffected individuals show bi-allelic expression, while the sole wild-type allele was transcribed in DM muscle. Our findings support a gene dosage effect in the pathogenesis of the disease.

Anticipation in myotonic dystrophy. II. Complex relationships between clinical findings and structure of the GCT repeat.

We studied the expansion of the GCT repeats within the myotonic dystrophy protein kinase gene in nine myotonic dystrophy (DM) kindreds. Southern blot and polymerase chain reaction analyses of the repeat region demonstrated the expansion in all 62 patients with the diagnosis of DM. Among 43 DM parent-child pairs, age of onset in the child was earlier than in the parent in 36 pairs, in the same decade as the parent in five, and undetermined in two.

A transposon-like element in the deletion-prone region of the dystrophin gene.

The central portion of the dystrophin gene locus is a preferential site for deletions causing progressive muscular dystrophy of the Duchenne type (DMD). The nucleotide sequence of a deletion junction fragment from a DMD patient was determined, revealing that the proximal breakpoint of the deletion in intron 43 fell within the sequence of a transposon-like element. This segment, belonging to the THE-1 family of human transposable elements, is normally present in a complete form in intron 43 of the dystrophin gene.

Triplet repeat mutations in human disease.

Triplet repeats are the sites of mutation in three human heritable disorders, spinal and bulbar muscular atrophy (SBMA), fragile X syndrome, and myotonic dystrophy (DM). These repeats are GC-rich and highly polymorphic in the normal population. Fragile X syndrome and DM are examples of diseases in which premutation alleles cause little or no disease in the individual, but give rise to significantly amplified repeats in affected progeny.

Point mutations and polymorphisms in the human dystrophin gene identified in genomic DNA sequences amplified by multiplex PCR.

About one third of Duchenne muscular dystrophy (DMD) patients have no gross DNA rearrangements in the dystrophin gene detectable by Southern blot analysis or multiplex exon amplification. Presumably, in these cases, the deficiency is caused by minor structural lesions of the dystrophin gene. However, to date, only a single human DMD case has been described where a point mutation, producing a stop codon, accounts for the DMD phenotype.

An unstable triplet repeat in a gene related to myotonic muscular dystrophy.

Synthetic oligonucleotides containing GC-rich triplet sequences were used in a scanning strategy to identify unstable genetic sequences at the myotonic dystrophy (DM) locus. A highly polymorphic GCT repeat was identified and found to be unstable, with an increased number of repeats occurring in DM patients. In the case of severe congenital DM, the paternal triplet allele was inherited unaltered while the maternal, DM-associated allele was unstable.

Variation of the CGG repeat at the fragile X site results in genetic instability: resolution of the Sherman paradox.

Fragile X syndrome results from mutations in a (CGG)n repeat found in the coding sequence of the FMR-1 gene. Analysis of length variation in this region in normal individuals shows a range of allele sizes varying from a low of 6 to a high of 54 repeats. Premutations showing no phenotypic effect in fragile X families range in size from 52 to over 200 repeats.

Beta-nerve growth factor (beta-NGF) mRNA expression in the parkinsonian adrenal gland.

The adrenal gland is a well-demonstrated source for different neurotrophic factors. The presence of the beta-nerve growth factor (beta-NGF) mRNA in the adrenal tissue used for grafting in a Parkinsonian patient is reported here. Adrenal samples were obtained on the day of implantation, and a specific cDNA was synthesized after the extraction of total RNA using a synthetic oligonucleotide as a reverse transcription primer.

Maintained cellular function of adrenal medullary cells in parkinsonian dysautonomia.

Adrenal gland involvement in Parkinson's disease was reported by different authors. Further studies became relevant after adrenal was proposed as dopaminergic donor for neurotransplantation. Chromaffin cells were grown in culture and the effects of nerve growth factor (NGF) tested: no differences were observed between parkinsonian and control cells.