Mutations of the noggin (NOG) and of the activin A type I receptor (ACVR1) genes in a series of twenty-seven French fibrodysplasia ossificans progressiva (FOP) patients.

Fibrodysplasia ossificans progressiva (FOP) is a rare but very severe disease, characterised by congenital malformations of the toes and by progressive heterotopic ossification of muscles and joints. Two genes, the noggin (NOG) gene and the activin A type I receptor (ACVRI) gene, are involved in FOP. In this study we have searched for the NOG and the 617G>A (ACVR1) mutations in a well characterized series of twenty-seven French FOP patients. Five NOG mutations (delta 42, 274G>C, 275G>A, 276G>A, and 283G>A) have been found in seven (26%) of our FOP patients. The 617G>A mutation in the ACVR1 gene is found in fourteen (52%) of the patients. With one exception (patient number 22), 617G>A and NOG mutations are mutually exclusive in patients. Mutations 274G>C, 283G>A and 617G>A segregate with the trait in five different FOP families, some members of them being partially affected by the disease.

A new mutation of the noggin gene in a French Fibrodysplasia ossificans progressiva (FOP) family.

A new mutation of the Noggin gene in a French Fybrodysplasia ossificans progressiva (FOP) family: Fibrodysplasia ossificans progressiva (FOP) is a very rare disease characterized by congenital malformation of the great toes and progressive heterotopic ossification of the muscles. We previously located a FOP gene in the 17q21-22 region and described several mutations of the noggin (NOG) gene (located in 17q22) in four FOP patients, including the G91C mutation which is transmitted dominantly in a Spanish FOP family. We describe in the present study a new mutation of the NOG gene in a French FOP family. This new mutation is a guanine to adenine change at nucleotide 283 (283G --> A) of the NOG gene, and is transmitted in the family (in the heterozygote form) by the affected mother to her two affected children. At the peptide level this mutation (A95T) substitutes an Alanine residue by a Threonine at position 95 of the Noggin protein. The Alanine mutated residue is located just adjacent to the myristoylation site of the protein, where all the mutations we described until now are located.

Follow-up of subjects with isolated and persistent anti-core (anti-p24 or anti-p17) antibodies to HIV.

Systematic screening of blood donations by enzyme-linked immunosorbent assay (ELISA) for HIV antibodies carries a false-positive rate: the sera involved react in Western blot to core antigens (p24 or p17) but reactivity to envelope is absent. We studied 22 subjects with persistent and isolated anti-core reactivities; 75 HIV seropositive patients were controls. The epidemiological data and the follow-up and biological tests performed in these two populations argue that donors with persistent and isolated anti-core antibodies are not seroconverting for HIV. We conclude: (1) that verification of all anti-HIV ELISA-positive sera by Western blot is essential and that the presence of at least once anti-envelope (gp120 or gp41) antibody is indispensable for the diagnosis of HIV infection; (2) that the solitary anti-p24 or anti-p17 bands observed on Western blot are false-positive. There is no evidence that donors with such reactivities are HIV-infected.

Distribution of the CCR5 gene 32-basepair deletion in West Europe. A hypothesis about the possible dispersion of the mutation by the Vikings in historical times.

The chemokine receptor CCR5 constitutes the major coreceptor for the macrophage-tropic strains of HIV-1. A mutant allele of the CCR5 gene named Delta32 was shown to provide to homozygotes a strong resistance against infection by HIV. The frequency of the Delta32 allele was collected in 7328 noninfected unrelated individuals from 31 different European populations, and in Cyprus, Turkey, Daghestan, and North-Africa. The Delta32 allele was found in all populations studied, with a mean frequency of about 8.0%. A north to south gradient correlating latitude with Delta32 allelic frequencies was found (r = 0.795, p < 10(-9)), with highest allele frequencies in Nordic countries. We hypothesized that the Delta32 allele was disseminated in Europe by the Vikings during the eighth to the tenth centuries, because the most elevated values of this variant are actually found in their actual populations, and because they raided during the corresponding period in most European countries.

North African genes in Iberia studied by Y-chromosome DNA haplotype V.

Haplotype V at the Y-chromosome specific DNA polymorphism (p49/TaqI) was reported in a study concerning 487 males originating from five different geographic locations in Iberia and North Africa. The highest frequency of haplotype V (68.9%) was previously observed in Berbers from Morocco, and it was previously established that this haplotype is a characteristic Berberian haplotype in North Africa. Percentages of haplotype V geographic distribution reveal a gradient of decreasing frequencies with latitude in Iberia: 40.8% in Andalusia, 36.2% in Portugal, 12.1% in Catalonia, and 11.3% in Basques; such a cline of decreasing haplotype V frequencies from the South to the North in Iberia clearly establishes a North African toward Iberian gene flow.

Allele doses of apolipoprotein E type epsilon 4 in sporadic late-onset Alzheimer's disease.

Apoliprotein E, type epsilon 4 allele (ApoE-epsilon 4) is associated with late-onset sporadic Alzheimer's disease (AD). We have found that the cumulative probability of remaining unaffected over time decreases for each dose of ApoE-epsilon 4 in sporadic, late-onset French AD. The effect of genotypes on age at onset of AD was analyzed using the product limit method, to compare unaffected groups during aging.

Mutation frequencies of the cytochrome CYP2D6 gene in Parkinson disease patients and in families.

The frequencies of five mutations of the debrisoquine 4-hydroxylase (CYP2D6) gene (mutations D6-A, B, C, D, and T), corresponding to poor metabolizer (PM) phenotypes, were determined by restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) in 47 patients with Parkinson disease, and compared with the findings in 47 healthy controls. These mutant alleles were about twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.12 (95% confidence interval, 1.41-2.62). There seem to be no significant differences in frequencies of mutant genotypes in patients among gender and modalities of response with levodopa therapy; but frequency of the mutations was slightly enhanced after age-at-onset of 60 years. Mutations D6-B, D, and T were detected in 7 patients belonging to 10 Parkinson pedigrees.

Identification of three novel mutations of the noggin gene in patients with fibrodysplasia ossificans progressiva.

We report noggin mutations in three Spanish families with fibrodysplasia ossificans progressiva (FOP). The three propositi have typical FOP findings; in the first and third families the parents are unaffected, while in the second family the father is partially affected. DNA of the three propositi and their parents was screened by sequencing for mutations in the noggin gene (NOG). Sequencing indicated a G to C mutation at nucleotide 274 of the NOG gene in the first propositus, encoding for the G92R substitution at the peptide level; this first mutation is de novo, the corresponding change not being observed in parents. In the second propositus, a G to T mutation at nucleotide 271 encodes for the G91C substitution, transmitted in the corresponding family by the partially affected father. In the third propositus, sequencing indicated a G to A mutation at nucleotide 275, encoding for the G92E substitution; this third mutation is de novo. All three mutations, as well as the Delta42 deletion already reported, resulted in the alteration of the portion of the NOG gene at positions 265-282, encoding for the potential N-myristoylation site at residues 89-GGGGGA-94.

Association of apolipoprotein E allele epsilon 4 with late-onset sporadic Alzheimer's disease.

Apolipoprotein E, type epsilon 4 allele (ApoE epsilon 4), is associated with late-onset sporadic Alzheimer's disease (AD) in French patients. The association is highly significant (0.45 AD versus 0.12 controls for epsilon 4 allele frequencies). These data support the involvement of ApoE epsilon 4 allele as a very important risk factor for the clinical expression of AD.

Familial adrenoleukodystrophy: long chain fatty acid levels and analysis with a factor VIII DNA probe.

Segregation studies of X-linked adrenoleukodystrophy (ALD) and a cloned desoxyribonucleic fragment (factor VIII gene), which detects polymorphism in the distal end of the long arm of the X chromosome (Xq28), are reported in a large sibship ALD family. The findings should permit better identification of carriers and add a new marker for identifying the ALD gene itself.

Variable number tandem repeat dopamine transporter gene polymorphism and Parkinson's disease: no association found.

We studied a variable number of tandem repeat polymorphisms in the dopamine transporter gene in search of an association with Parkinson's disease in a French population. Five alleles were detected, consisting of 7, 8, 9, 10 and 11 copies of the 40-base pair repeat sequence, of which the 10-copy allele was the most common. There was no significant difference between the patients and the control subjects in the distribution frequencies of the alleles or genotypes, or in ages at onset in patients between the main allelic classes.

Frequencies of the CC chemokine receptor 5 delta 32 allele in various populations of defined racial background.

The 32-nucleotide deletion (delta 32) within the chemokine co-receptor CCR5 gene was studied in 1,031 DNA samples from various racial origins. The mutation is absent in 48 Vietnamese living in Paris, and we confirm that delta 32 allele is very rare in a sample of 302 individuals originating from sub-Saharan Africa. The mean delta 32 allelic frequency in unrelated non-HIV-1 infected blood donors is 0.113 in France, as calculated in a sample of 620 individuals. A slight decrease in allelic frequencies was noticed in the southern part of the country compared to the Paris region. In a population of 71 North African people the delta 32 frequency is 0.063, a value significantly lower than the mean frequency observed in France.

Absence of a close linkage between Alzheimer's disease susceptibility gene and a polymorphic DNA probe coding for beta-amyloid.

The hypothesis of a connection between Alzheimer's disease (AD) gene and the probe coding for beta-amyloid (beta-A), located on chromosome 21, was investigated in a large study group from Calabria, in which AD was transmitted as an autosomal dominant Mendelian trait. Segregation analysis of one EcoRI restriction polymorphism of beta-A, after molecular hybridization with a long cDNA probe of DNAs from key-individuals in the study group, determined that there was not a close connection between AD and beta-A.

Study of the mutation M694V of familial Mediterranean fever in Jews.

Familial Mediterranean fever (FMF) is a recessively inherited disorder characterized by episodes of fever with abdominal pain, pleurisy, or arthritis. The familial Mediterranean fever gene, designated MEFV, was recently cloned, and the missense mutation M694V accounting for most of the patients with this disease was identified. The objective of the present study was to establish frequencies of the M694V mutation in three groups of Jews. The subjects studied were 381 Sephardi, 256 Ashkenazi, and 65 Oriental Jews, all male subjects, previously collected for an anthropological study, independent of their FMF status. The M694V mutation in the 702 samples was assessed by amplifying genomic DNA with the use of primers that selectively amplify the normal or altered DNA sequence of the M694V mutation, by the amplification refractory mutation system (ARMS). In our sample of Sephardi Jews, the frequency of the M694V mutation is elevated (10.9%), and this is also the case for Oriental Jews (9.2%). In our sample of Ashkenazis, the M694V allele frequency is very low (0.8%).

Celtic origin of the C282Y mutation of hemochromatosis.

The main hereditary hemochromatosis mutation C282Y in the HFE gene was recently described, and the C282Y frequencies were reported for various European populations. The aim of this synthesis is to compile the Y allele frequencies of the C282Y mutation for 40 European populations. The most elevated values are observed in residual Celtic populations in Ireland, the United Kingdom, and France, in accordance with the hypothesis of Simon et al. (1980) concerning a Celtic origin of the hereditary hemochromatosis mutation.

Meta-analysis of GJB2 mutation 35delG frequencies in Europe.

Mutations in the gene encoding connexin-26 (specified GJB2) have been shown to be a major cause of nonsyndromic recessive deafness (NSRD), and a single mutation 35delG in the GJB2 gene accounts for the majority of cases of NSRD. This mutation was screened in France and in other European populations by a reliable PCR method. We present here a meta-analysis of the 35delG frequencies in 4123 random controls from 20 European countries, and show that the mutation is more frequent in the south of Europe than in the north; a north-south increasing cline of 35delG frequencies is established (r = -0.527).

CCR5-Delta32 allele frequencies in Ashkenazi Jews.

This study was carried out to determine the 32-bp deletion allele frequencies in the CCR5 gene (CCR5-Delta32) in various populations of Jews of eastern European origin (Ashkenazi Jews). The total population sample (n = 351) represented Ashkenazi Jews originating from seven geographic groups in Europe. The overall frequency of the CCR5-Delta32 allele was elevated (13.7%), although some important differences in frequencies occurred among the seven countries included in the survey; the frequency was highest (25.9%) in those of Lithuanian origin. There is an apparent trend (r = 0.74) involving a lowering of the Delta32 allele frequencies moving from north to south in the seven populations tested. The Delta32 frequencies obtained were compared to those already published for non-Jewish populations inhabiting the same countries and the differences in frequencies were not significant, with the exception of Lithuania (chi(2) = 2.20, p < 0.03). Founder effect and genetic drift are proposed to explain the elevated values observed in Ashkenazi Jews and those originating from Lithuania.

Confirmation of a gene for multiple sclerosis (MS) to chromosome region 19q13.3.

To identify the chromosomal localizations of the multiple sclerosis (MS) genes, we conducted a genomewide linkage analysis using eighteen affected families. A MS gene is linked to markers located in the 19q13.3 region (multipoint lod-score = 2.1). Apolipoprotein E (ApoE) gene, located in this region, is an excellent candidate gene for MS because the ApoEe4 allele is acting as a severity allele in the disease.

Neonatal detection of the 35delG mutation of the GJB2 gene in families at risk for deafness.

About half of congenitally deaf children that have a recessively inherited sensorineural deafness are born from normal-hearing parents and have no risk factor for hearing loss. Mutation 35delG in the connexin-26 gene is in European populations the basis for around half of all recessively inherited prelingual sensorineural deafness. The aim of our study was to assess the efficacy and utility of the 35delG mutation of the connexin-26 gene analysis for neonates at familial risk, from DNA isolated from Guthrie newborn screening cards. Newborns who had consanguineous parent and/or a familial history of deafness underwent connexin-26 gene analysis from DNA isolated from Guthrie cards and two hearing screening tests (transient evoked otoacoustic emissions, and auditory brainstem recordings). 24 newborns were includes in this pilot study; one of them is homozygous for the 35delG mutation and had abnormal hearing screening tests; all the others newborns had normal connexin gene and at least one normal hearing screening test. Detection on connexin-26 gene mutation is feasible in selected at-risk newborns on one additional blood spot on Guthrie card.