Molecular diagnosis of lecithin: cholesterol acyltransferase deficiency in a presymptomatic proband

OBJECTIVE: The study compared two commercial chlorhexidine mouthrinses (Chlorhexamed 0.1% and Corsodyl 0.2%) for their effects on dental plaque and gingival inflammation, their side effects (eg, tooth staining and mucosal irritation), and patient acceptance. METHOD AND MATERIALS: One hundred thirty healthy volunteers were randomly distributed into two groups of 65 each. Each volunteer had gingivitis or chronic marginal periodontitis and used the rinse two times a day for 4 weeks. The sulcular bleeding index, approximal plaque index, gingival index, and a discoloration index were taken at baseline and once a week thereafter. The patients were questioned about taste disturbances, mucosal irritation, and their perception of the taste of the mouthrinse. RESULTS: In both groups, after 4 weeks, the mean sulcular bleeding index, approximal plaque index, and gingival index scores had decreased significantly. The discoloration index had increased significantly in both groups. There were no statistically significant differences between the two mouthrinses in any of these measurements. There were no significant differences in side effects reported by the two groups. CONCLUSION: The increase in concentration of chlorhexidine provided no clinical advantages or disadvantages.     

Molecular genetic analysis of McArdle''s disease in Spanish patients

As the extracardiac Fontan operation evolves, a reliable method for creating and subsequently closing communications between the systemic and pulmonary venous chambers would be useful. We describe a surgical technique for creating this "fenestration" and a complementary transcatheter technique that allows safe and reliable closure of these communications regardless of size and position.     

Molecular analysis and genetic mapping of the rhodopsin gene in families with autosomal dominant retinitis pigmentosa

Eighty-eight patients/families with autosomal dominant retinitis pigmentosa (RP) were screened for rhodopsin mutations. Direct sequencing revealed 13 different mutations in a total of 14 (i.e., 16%) unrelated patients. Five of these mutations (T4K, Q28H, R135G, F220C, and C222R) have not been reported so far. In addition, multipoint linkage analysis was performed on two large families with autosomal dominant RP due to rhodopsin mutations by using five DNA probes from 3q21-q24. No tight linkage was found between the rhodopsin locus (RHO) and D3S47 (theta max = 0.08). By six-point analysis, RHO was localized in the region between D3S21 and D3S47, with a maximum lod score of 13.447 directly at D3S20.     

Molecular genetic testing in the diagnosis of sporadic cases of Huntington's chorea

Huntington's disease is characterized by autosomal dominant transmission and a complete penetrance of the mutant gene. Mutation in Huntington's disease consists in expansion of the unstable tandem CAG-trinucleotide repeats. This discovery allowed to perform a precise DNA diagnosis of the mutant gene carriers. Direct DNA diagnosis has a special importance in sporadic cases of the disease. We performed direct DNA diagnosis in 4 patients with sporadic choreic hyperkinesis, and elaborated a modified protocol for DNA amplification. The obtained results are discussed from the viewpoint of current knowledge about the nature of the Huntington's disease gene.     

Preimplantation diagnosis for Huntington's disease (HD): clinical application and analysis of the HD expansion in affected embryos

Huntington's disease (HD) is an autosomal dominant disease characterized by motor disturbance, cognitive loss and psychiatric manifestations, starting between the fourth and the fifth decade, followed by death within 10-20 years of onset of the disease. The disease-causing mutation is an expansion of a CAG triplet repeat at the 5' coding end of the Huntington gene. We have developed a single-cell PCR assay for the HD gene in order to propose preimplantation genetic diagnosis (PGD) for the couples at risk. We present here our first results with our first nine PGD cycles and also discuss the behaviour of the disease-causing expansion in pre-implantation embryos.     

Correlation between the onset age of Huntington's disease and length of the trinucleotide repeat in IT-15

Huntington's disease (HD) is an autosomal dominant disorder with a variable age of onset that is influenced by the sex of the affected parent. The recent recognition that HD is caused by an expanded triplet repeat suggests the possibility that the onset age may be predicted by the length of the repeat. This hypothesis was tested by assaying the length of the repeat in 114 individuals who were clinically diagnosed with HD and had a known onset age. Every individual had an expanded allele. The range was from 36 to 82 repeats (mean = 48.4 +/- 9.51) and larger than the normal range (6 to 31). The size of the expanded allele was correlated with the age of onset (r = -0.65 p < .0001). Despite the highly significant correlation, the repeat size explains less than half of the variance in onset age. Furthermore, the age of onset cannot be predicted from the size of the triplet repeat, particularly if the number of repeats is in the smaller end of the expanded range. If the repeat is < or = 50 triplets, the amount of variation in the age of onset explained by the length of the triplet repeat is less than 10%. As an illustration, the onset age of individuals with 39 repeats ranges from 30 to 65 years old. The sex of the affected parent had no effect in our sample beyond the effect of the length of the repeat. Affected offspring of affected fathers had longer repeats and a larger variance in allele size than offspring of affected mothers, perhaps reflecting greater instability in paternal transmission.     

Molecular analysis of the IgH gene in 212 cases of Hodgkin's disease: correlation of IgH clonality with the histologic and the immunocytochemical features

The aims of this study are to evaluate the frequency of clonal immunoglobulin heavy chain gene rearrangements in paraffin-embedded samples of Hodgkin's disease (HD) with use of the polymerase chain reaction method and to correlate the molecular findings with the histologic and immunocytochemical features. DNA extracts from paraffin-embedded sections from 212 HD samples were used for amplification of the IgH gene by use of framework 2 and framework 3 region primers. Immunohistochemical studies were performed on paraffin sections by use of monoclonal antibodies for CD20 and latent membrane protein-1 and polyclonal antibody for CD3. With use of both primer combinations, monoclonality was detected in 18.7% of lymphocyte-predominant HD cases and in 32.2% of classical HD cases. These results suggest that immunoglobulin heavy chain gene clonal rearrangements are relatively frequent in classical HD. In addition, the statistical analyses of the genotypic and immunocytochemical data revealed that the detection of B-cell populations is significantly associated with the expression of CD20 on HRS cells. There was, however, no correlation between the histologic subtype, the percentage of HRS cells, the presence of latent membrane protein-1 expression, and the molecular analysis results.     

Molecular analysis of the aspartylglucosaminidase gene in Japanese patients with aspartylglucosaminuria

Molecular analysis of the aspartylglucosaminidase (AGA) gene was performed on two Japanese siblings with aspartylglucosaminuria (AGU). They were the first Japanese patients diagnosed as AGU and up to now, no other patients with AGU have been discovered in Japan. AGA cDNA from one patient contained 7-nt (TCTCCAG) insertion between exons 3 and 4, which was identical with the 3'-terminal sequence of intron 3. Sequencing of amplified genomic DNA from both patients showed the same single base transition (A-->G) at the 5'-side adjacent to the insertion sequence. This mutation newly created a consensus AG dinucleotide at the 3'-splice site and caused alternative splicing of AGA pre-mRNA by leaving the 3'-terminal 7-nt of intron 3. BsmAI restriction site analysis of amplified genomic DNA indicated that they were homozygotes of this mutation. We conclude that splicing defect of intron 3 caused AGA deficiency in them.     

Mutational analysis of the Jagged 1 gene in Alagille syndrome families

Alagille syndrome (AGS) is an autosomal dominant disease characterized by five major abnormalities in the liver, heart, face, vertebrae and eye. The responsible gene has been recently identified as the human Jagged 1 (JAG1) gene, which encodes a ligand for the Notch receptor. We analyzed the JAG1 gene in eight AGS families, including affected and unaffected individuals, at the genomic DNA level, mainly by single-strand conformational polymorphism (SSCP) and DNA sequencing analysis. Four categories of mutations were identified: (i) four frameshift mutations in exons 9, 22, 24 and 26 were exhibited respectively in affected individuals of four AGS families, which resulted in moving the translational frame of JAG1; (ii) one nonsense mutation, a 1 bp substitution in exon 5 of the EGF-like repeat domain, was detected in two unrelated AGS families, which altered codon 235 from arginine to stop; (iii) one acceptor splice site mutation of exon 5 was revealed in a sporadic patient; and (iv) a 1.3 Mb deletion, which included the entire JAG1 gene, was found in another patient. Our results further demonstrate that AGS is a dominant disease and suggest that the JAG1 gene exerts a fundamental role in regulating genes involved in development.     

Molecular analysis of the von Hippel-Lindau disease tumor suppressor gene in human lung cancer cell lines

The deletion of the short arm of chromosome 3 is frequently observed in lung cancer. To determine whether the von Hippel-Lindau (VHL) disease tumor suppressor gene located at 3p25 is responsible for oncogenesis in lung cancer, we searched the known open reading frame using the single-strand conformation polymorphism (SSCP) technique for mutations in the VHL gene in 72 cancer cell lines including small cell (SCLC) and non-small cell (NSCLC) lung cancers, carcinoids, and mesotheliomas. SSCP analysis showed that four cell lines have altered SSCP patterns within the coding region and one in an intron of the VHL gene. SCLC line NCI-H1672 had a somatic mutation, G to A at nucleotide (nt) 530, leading to amino acid substitution (glycine to aspartic acid) compared to normal DNA from the same patient. Mesothelioma line NCI-H28 had T to A mutation at nt 479 leading to leucine to histidine amino acid change. We found one frequent polymorphism A (0.72) or G (0.28) at nt 19 resulting in either serine or glycine at this position, changes also found in normal peripheral blood cell DNA, often in a heterozygous state. In addition, we found single rare polymorphisms which did not alter the coding region including: C to G at nt 396, G to T at nt 843, and C to T change in an intron. These results suggest that the VHL gene is only rarely mutated in thoracic malignancies.     

Longitudinal analysis of phonemic clustering and switching during word-list generation in Huntington's disease.

Two characteristics of word-list generation performance are forming clusters (i.e., contiguous words from the same subcategory) and switching among them. Patients with frontal lobe pathology show reduced switching on letter-cued word generation tasks, and clustering has been associated with temporal lobe functioning. Letter-cued word generation was examined in 72 patients with Huntington"s disease (HD) and 41 healthy participants of equivalent age and education. As predicted, the patients showed reduced switching but normal clustering. In addition, switching but not clustering correlated inversely with disease severity, as measured by both movement and mental status scales. Furthermore, 5-year longitudinal analysis revealed a monotonic decrease in switching over time, whereas clustering performance remained stable. Control participants performed uniformly over time on both measures. These results are consistent with a progressive reduction in cognitive flexibility attributed to disruption of frontal circuits secondary to neostriatal pathology in HD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular analysis of the PDS gene in Pendred syndrome

Pendred syndrome is an autosomal recessive disorder characterized by the association between sensorineural hearing loss and thyroid swelling or goitre and is likely to be the most common form of syndromic deafness. Within the thyroid gland of affected individuals, iodide is incompletely organified with variable effects upon thyroid hormone biosynthesis, whilst the molecular basis of the hearing loss is unknown. The PDS gene has been identified by positional cloning of chromosome 7q31, within the Pendred syndrome critical linkage interval and encodes for a putative ion transporter called pendrin. We have investigated a cohort of 56 kindreds, all with features suggestive of a diagnosis of Pendred syndrome. Molecular analysis of the PDS gene identified 47 of the 60 (78%) mutant alleles in 31 families (includes three homozygous consanguineous kindreds and one extended family segregating three mutant alleles). Moreover, four recurrent mutations accounted for 35 (74%) of PDS disease chromosomes detected and haplotype analysis would favour common founders rather than mutational hotspots within the PDS gene. Whilst these findings demonstrate molecular heterogeneity for PDS mutations associated with Pendred syndrome, this study would support the use of molecular analysis of the PDS gene in the assessment of families with congenital hearing loss.     

Visual attention and perception in patients with Huntington's disease: comparisons with other subcortical and cortical dementias

Shifts in attention were examined in patients with Huntington's disease (HD) using a divided attention paradigm that involved the presentation of global-local stimuli. The HD patients' pattern of performance was compared to the previously reported results of groups of patients with Alzheimer's disease (AD; Filoteo et al., 1992) or Parkinson's disease (PD; Filoteo et al., 1994). Across consecutive trials of the divided attention task, a visual target could appear at either the same global-local level or at a different level. When the target changed levels across consecutive trials, the AD patients demonstrated an impairment in disengaging attention from the level at which the last target appeared, whereas the PD patients were impaired in maintaining their attention at the previously attended level. In contrast to these patterns of performances, the HD patients did not demonstrate a significant impairment in shifting attention between hierarchical levels. Both the AD and the PD patients' abnormal shifting ability was significantly related to the number of errors they made in identifying target stimuli; however, the pattern of the relationship was qualitatively distinct. These results suggest that different attentional mechanisms may underlie AD and PD patients' visual-perceptual deficits. The HD patients' shifting ability was not related to the number of errors they made in identifying target stimuli, suggesting that a different mechanism may account for the visual-perceptual impairments exhibited by these patients.     

Molecular genetics of Krabbe disease (globoid cell leukodystrophy): diagnostic and clinical implications

Galactocerebrosidase (GALC) is a lysosomal beta-galactosidase responsible for the hydrolysis of the galactosyl moiety from several galactolipids, including galactosylceramide and psychosine. The deficiency of this enzyme results in the autosomal recessive disorder called Krabbe disease. It is also called globoid cell leukodystrophy (GLD), because of the characteristic storage cells found around cerebral blood vessels in the white matter of affected human patients and animal models. Although most patients present with clinical symptoms before 6 months of age, older patients, including adults, have been diagnosed by their severe deficiency of GALC activity. More than 40 mutations have been identified in patients with all clinical types of GLD. While some mutations clearly result in the infantile type if found homozygous or with another severe mutation, it is difficult to predict the phenotype of novel mutations or when mutations are found in the heterozygous state. A high incidence of polymorphic changes on apparent disease-causing alleles also complicates the interpretation of the effects of mutations. The detection of mutations has greatly improved carrier identification among family members and will permit preimplantation diagnosis for some families. The molecular characterization of the naturally occurring mouse, dog, and monkey models will permit their use in trials to evaluate different modes of therapy.     

Impairments of movement kinematics in patients with Huntington's disease: a comparison with and without a concurrent task

This study aimed to quantify the efficiency and smoothness of voluntary movement in Huntington's disease (HD) by the use of a graphics tablet that permits analysis of movements profiles. In particular, we aimed to ascertain whether a concurrent task (digit span) would affect the kinematics of goal-directed movements. Twelve patients with HD and their matched controls performed 12 vertical zig-zag movements, with both left and right hands (with and without the concurrent task), to large or small circular targets over long or short extents. The concurrent task was associated with shorter movement times and reduced right-hand superiority. Patients with HD were overall slower, especially, with long strokes, and had similar peak velocities for both small and large targets, so that controls could better accommodate differences in target size. Patients with HD spent more time decelerating, especially with small targets, whereas controls allocated more nearly equal proportions of time to the acceleration and deceleration phases of movement, especially with large targets. Short strokes were generally less force inefficient than were long strokes, especially so for either hand in either group in the absence of the concurrent task, and for the right hand is its presence. With the concurrent task, however, the left hand's behavior changed differentially for the two groups; for patients with HD, it became more force efficient with short strokes and even less efficient with long strokes, whereas for controls, it became more efficient with long strokes. Controls may be able to divert attention away from the inferior left hand, increasing its automaticity, whereas patients with HD, because of disease, may be forced to engage even further online visual control under the demands of a concurrent task. Patients with HD may perhaps become increasingly reliant on terminal visual guidance, which indicates an impairment in constructing and refining an internal representation of the movement necessary for its effective execution. Basal ganglia dysfunction may impair the ability to use internally generated cues to guide movement.