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Several lines of evidence suggest that RBFOX1 is a key regulator of transcriptional and splicing programs in neural cells during development, and that it is expressed in a neuronal module enriched for known autism susceptibility genes. We have investigated its expression by semiquantitative RT-PCR in accessible nonbrain resources in eighteen autism spectrum disorder sib-pairs belonging to the Italian Autism Network cohort. RBFOX1 gene expression was detected in lymphoblastoid cell lines but not in lymphocytes. No significant differences between autism spectrum disorders and non-affected brothers were found. We were not able to replicate in lymphoblastoid cell lines the previously reported RBFOX1 gene downregulation in autism, even if a trend was observed. This might be due to less pronounced transcription level differences in RBFOX1 gene expression in lymphoblastoid cell lines than in brain samples., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

P-selectin is an adhesion molecule involved in the pathogenesis of inflammation, thrombosis, and oncogenesis. In this study of 51 polymorphisms in candidate genes for cardiovascular disease in 1561 individuals, we identified a new allelic variant of the SELP gene, g.18196_20704del, that determined the lack of genotyping for one polymorphism in one individual. It is a deletion of 2509 nucleotides which starts in intron 6 and ends in intron 8. Re-genotyping of 1023 apparent homozygotes indicated an overall allele frequency of 0.27%. The inclusion of this allelic variant in genetic association studies will avoid genotyping errors and marginally improve the sensitivity.

We present the molecular genetic analysis of an infantile-onset Sandhoff disease patient. Genomic DNA amplification, heteroduplex analysis, cloning and sequencing revealed a 4-bp deletion in exon 4 (497 DeltaAGTT). The result is a frameshift mutation that leads to a stop codon in exon 5. This mutation is associated with a dramatic decrease of HEXB mRNA levels., (Copyright 2001 Academic Press.)

A C-->T transition at nucleotide 9168 of COL1A1 genomic sequence (GenBank AF017178) was found in three unrelated patients, during the search for OI causal mutations. This polymorphic variant was then tested in the general population by Taq I restriction of genomic DNA amplified with a specifically designed restriction enzyme site-generating oligonucleotide primer. Allelic frequencies were found to be: 0.88 (C allele) and 0.12 (T allele), respectively., (Copyright 1999 Academic Press.)

The authors present two new missense mutations in exon 1 of the adrenoleukodystrophy (ALD) gene. The first, a C813T transition, results in the substitution Pro143 Ser in the third putative transmembrane domain of the adrenoleukodystrophy protein (ALDP) in an adult onset case. The second, a de novo C709T transition, results in a substitution Ser 108 Leu between the second and the third putative transmembrane segments, in a childhood case., (Copyright 1999 Academic Press.)

A novel mutation, a C-->T transition at nucleotide 455 of the coding sequence of the ARSA gene, was found in a control individual during the search for metachromatic leukodystrophy mutations. Its distribution in three different populations was examined. The frequency of the T allele was 0.058, 0.025 and 0.033, in Italian, German and Greek populations, respectively. The mutation results in no amino acid substitution and can be identified as it creates a a polymorphic site for the restriction endonuclease N/aIII.

Cleavage fragment length polymorphism analysis with silver staining visualization (CFLPA-SS) was used for the detection of mutations previously detected by single strand conformation (SSCA) or heteroduplex analyses (HA); in order to assess this new method for mutation screening. The analysed mutations include single nucleotide transitions, transversions, a deletion and a duplication in the following genes: CFTR (cystic fibrosis transmembrane conductance regulator), COL4A5 (collagen type 4 alpha 5 chain), PKD1 (polycystic kidney disease 1), and FGFR3 (fibroblast growth factor receptor 3). Peripheral blood leukocyte genomic DNA was isolated, amplified by polymerase chain reaction (PCR), and then cleaved by Cleavase I enzyme at different temperatures. Electrophoresis of the fragments on denaturing polyacrylamide gel was followed by silver staining for 1 min. All 13 mutations investigated were reproducibly detected. CFLPA-SS proved to be a reliable method for mutation detection and more rapid than SSCA and HA.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common single gene diseases in humans. We have identified a synonymous T to C transition polymorphism in exon 46 of the PKD1 gene (12838T-->C, Pro4209Pro). The polymorphism was present with similar frequencies in ADPKD patients and unaffected individuals. The heterozygosity, determined in 89 Italian individuals, was 0.347. The frequency of the rarer allele was 0.222. This polymorphism is easy to determine as it abolishes a naturally occurring Ddel restriction site. The availability of an additional intragenic marker in the PKD1 gene will improve the accuracy of linkage studies in ADPKD families.

Fibroblasts from a 23 week old fetus affected with lethal (type II) osteogenesis imperfecta (OI) produced normal and abnormal type I procollagen molecules. The abnormal molecules were shown to contain pro alpha 1(I) chains in which the glycine at position 382 of the triple helical domain was substituted by arginine, as the result of a G-to-C transversion at nucleotide 1797 of the pro alpha (I) coding sequence. Also fibroblasts from the apparently normal father produced abnormal type I collagen but the overmodified alpha 1(I) chains tended to disappear with increasing passage number. We determined that the mutant allele accounted for approximately 36% of the COL1A1 alleles in the father's skin fibroblasts. Upon careful clinical reexamination, the man appeared to be very mildly affected with OI. The most plausible explanation for such a phenotypic variation is that the father is a mosaic for a mutation that is lethal in the heterozygous son. This finding confirms previous observations that somatic mosaicism for new dominant mutations is responsible for extreme intrafamilial variability and poses some caveats in genetic counselling.

We have developed a rapid, non-radioisotopic PCR fingerprinting technique for analysis of the HLA-Class II DQA gene second exon polymorphism, and have applied it to DNA samples from 210 healthy individuals. The technique is based on the formation of specific patterns (fingerprints) of homoduplexes or heteroduplexes between in vitro amplified DNA sequences. After electrophoresis on non-denaturing polyacrylamide gels and ethidium bromide fluorescence or silver staining, different HLA-DQA types give allele-specific banding patterns. HLA DQA typing is done by visual comparison between the sample's fingerprint patterns and appropriate controls. Similar fingerprints can be resolved by mixing the sample with a standard DNA in an amplified 'DNA crossmatch'. This application of PCR fingerprinting is useful to confirm the HLA-DQA serological typing and to improve the molecular characterization of this polymorphic region.

We report the allele and genotype frequencies in Italians of eight unlinked commonly utilized polymorphic loci: HUMTH01, HUMFES/FPS, HLA-DQA1, LDLR, GYPA, HBGG, D7S8 and GC. Genomic DNA from at least 100 individuals was amplified by PCR and typed after electrophoresis (HUMTH01, HUMFES/FPS), or reverse dot-blot (HLA-DQA1 and the other five loci). The allelic frequencies determined were compared with available population data. These results are useful for population and individual identification studies.

Non-isotopic DNA single-strand conformation analysis and heteroduplex analysis by ethidium bromide fluorescence visualization (SSCAE and HAE, respectively) were compared for the detection of 15 different naturally occurring mutations in 15 different DNA samples. The mutations included single nucleotide transitions, transversions and deletions, in CFTR (cystic fibrosis transmembrane conductance regulator), COL4A5 (collagen type IV alpha 5 chain), HEXB (hexosaminidase B), and COL1A2 (collagen type 1 alpha 2 chain) genes, responsible for diseases of medical interest. Genomic DNA from peripheral blood leukocytes or cDNA from reverse-transcribed fibroblast mRNA were amplified by polymerase chain reaction (PCR), and then analysed by two SSCAE and one HAE protocol. Fourteen out of 15 mutations (93%) were detected with one or the other method. HAE was more sensitive than SSCAE for the larger products (257-426 bp). The only undetected mutation was then identified with the use of a different primer, located farther from the mutation was then identified with the use of a different primer, located farther from the mutation site, thus increasing the combined efficiency of the two methods to 100%. We believe that combined use of SSCAE and HAE is a good, cheap and safe approach for mutation screening in a human gene.

We have been screening a cohort of 225 chromosomes from cystic fibrosis patients for mutations in the cystic fibrosis transmembrane regulator gene using a combination of DGGE,RNA-SSCP and DNA sequencing. A novel splice site mutation was detected by multiplex DGGE in a homozygous patient. Restriction-site generating PCR (RG-PCR) analysis demonstrated that both parents carried the same mutation. The molecular haplotype was the same. All the known ancestors came from the same (Veneto) region, and no consanguinity was documented up to the sixth generation.

The androgenetic origin of hydatidiform moles, due to a monospermic or dispermic mechanism, has been reported, and a possible pathogenetic relation with blighted ova suggested. To evaluate the origin of hydatidiform moles and their genetic relationship with blighted ova we investigated a series of samples, utilizing several hypervariable DNA polymorphisms by Southern blotting or PCR. Seven complete or partial hydatidiform mole and 49 blighted ovum cases were investigated. The results confirm the androgenetic origin of complete hydatidiform moles, which were always due in our sample to a monospermic mechanism. Our data exclude a relationship between hydatidiform moles and blighted ova, as in the latter a mixed paternal and maternal DNA contribution was always shown. A high incidence of chromosomal abnormalities in blighted ova was also found.

A multilocus genotype survey of 190 to 352 chromosomes was performed in Italians. Genomic DNA of five tandem repeat loci was amplified in vitro with the polymerase chain reaction. Variable number of tandem repeat (VNTR) or short tandem repeat loci investigated were: D1S80; AP0B, located in the 3' flanking region of the apolipoprotein B gene; D17S5; F8VWF, located in intron 40 of the von Willebrand factor gene; and D6S89. The repeat motif was from 2 to 70 bp. The polymerase chain reaction product size was from 100 to 1070 bp. Relative allele frequencies exhibited bimodal or complex distributions. The number of alleles detected in the sample varied from 10 for F8VWF to 20 for D1S80. The observed heterozygote frequencies of the loci ranged from 0.75 for D17S5 and F8VWF to 0.83 for D1S80, and were in accord with expected frequencies. No mutations were detected in a total of 566 meioses for the five loci studied. The most frequent genotype for all five loci combined has a frequency of 4.1 x 10(-6). In 90 parental determination cases, D1S80, AP0B, D17S5 and F8VWF gave conclusive information in 39/45 exclusions and in 21/45 attributions.

In this report we describe the use of a DNA amplification technique in which modified primers introduce a base substitution adjacent to the codon of interest and create an artificial restriction site for the detection of mutations which do not produce or modify a naturally occurring restriction site (restriction site generating-polymerase chain reaction, RG-PCR). RG-PCR was developed and applied to the screening in an Italian population sample of several relatively common cystic fibrosis mutations which are not amenable to analysis with a known restriction endonuclease: G542X, 2869insG, Y913C, N1303K, and 1717-1GA. This method, which allows the identification of virtually any single base change by restriction enzyme analysis and without the need for molecular probes, is rapid and easy to perform. The combined use of RG-PCR for several different CF mutations in multiplex tests further expands the advantages of this approach.