We describe a unique six-generation, highly consanguineous family originating from an isolated mountainous village in the Russian province of Daghestan. Three separate clinical phenotypes of progressive muscular dystrophy were identified in this large family. Seven patients developed a classical limb-girdle variant of muscular dystrophy (LGMD), with disease onset at 15-30 years and loss of ambulation within a 25-year course. The second group included three patients with a slowly progressive distal myopathy first manifested in the late teens and confined to the tibial and calf muscles. Each of these two phenotypes segregated independently as an autosomal recessive trait, and muscle biopsies showed non-specific myopathic changes. Lastly, two male siblings exhibited an atypical variant of Duchenne muscular dystrophy confirmed by detection of a deletion in the dystrophin gene. To clarify the molecular basis of the polymorphic autosomal recessive form of muscular dystrophy in this kindred, we performed molecular genetic studies on 67 family members and obtained significant evidence for linkage to chromosome 2p. A maximum pairwise lod (logarithm of odds) score of 5.64 was achieved at the zero recombination fraction (i.e. at theta = 0.00) for locus D2S291; multipoint linkage analysis confirmed the most likely location of a mutant gene near D2S291. The patients with LGMD and those with the distal muscular dystrophy phenotype share a common affected homozygous haplotype associated with the same founder chromosome; key recombinants defined D2S286 and D2S292 to be the closest loci flanking the mutant gene. Remarkably, two clinically distinct forms of autosomal recessive muscular dystrophy, LGMD type 2B (LGMD2B) and Miyoshi myopathy, were recently mapped to the same locus. We suggest that all three chromosome 2p-linked conditions may represent allelic disorders, i.e. different phenotypic expressions of a single gene.

Four different polymorphisms in the human p53 gene (a 16-bp duplication in intron 3, and three RFLPs: for Bsh1236I at codon 72, for MspI in intron 6 and for BamHI in the 3' flanking region) and extended haplotypes were studied in nine geographically diverse populations from Russia and Belarus. The Yakuts differed from all other populations, as they had a significantly higher frequency of the BamHI A1 allele. Most populations did not differ significantly from each other in the frequency of the Bsh1236I polymorphism. The 16-bp duplication A1 allele and MspI A2 allele frequencies were significantly higher in the Yakut and Khant populations. Linkage disequilibrium values (D') between BamHI and other polymorphic sites were not significant in many cases; for this reason we have used the 16 bp-Bsh1236I-MspI haplotype frequencies only. Of eight possible haplotypes, five were observed in the populations investigated. Haplotype 1-2-2 was the most frequent in all populations. The next most common haplotype, 1-1-2, was present at very similar frequencies among the Byelorussians and Russians from Smolensk, but was more frequent in other populations. The frequency of haplotype 2-1-1 showed a nearly continuous decrease from West to East (from 17.857% among the Byelorussians to 0.685% in the Yakuts from the Verkhoyansk) and correlated with longitude (Spearman's r = -0.8667, P = 0.0025), which may be due to natural selection and adaptation. The relationships among populations were evaluated by means of Nei's D(A) distances for the 16 bp-Bsh1236I-MspI haplotype frequencies. Based on the multidimensional scaling analysis a correlation between p53 haplotype frequencies and ethnicity is supposed.

No abstract

We studied the association between coronary artery disease (CAD) and polymorphisms of the ABCA1, ACE, AGT, eNOS and EFNB3 genes in 85 Russian patients with angiography-proven CAD and 100 of their siblings. No gene analyzed had a z-score value of more than 2.47 for CAD or for its main clinical presentations due to sibling transmission/ disequilibrium test (S-TDT). However, the DD genotype of ACE is significantly more prevalent in siblings with CAD [p = 0.025, relative risk (RR) 2.8], angina (p = 0.028, RR = 3.3) and myocardial infarction (MI) (p = 0.018, RR = 5.5). An increased risk of CAD, and its main manifestations, was associated with the R1587 allele of the ABCA1 gene: the RR for developing CAD was 4.88, for MI 6.18, and for angina 3.69 for siblings who were carriers of the R1587R and R1587K genotypes. Index of stenosis was significantly higher in probands with the K219K and R219K genotypes (p = 0.001). The combination of genotype K219K with R219K was more frequent among siblings with CAD (p = 0.044, RR = 2.38), arterial hypertension (p = 0.023, RR = 2.87) and angina (p = 0.027, RR = 3.3). Thus, none

Twenty blood samples from Russian patients (Moscow) with idiopathic motor neurone disease were analysed for mutations in the Cu,Zn superoxide dismutase (Cu,Zn SOD) gene. Two patients (10%) with the amyotrophic lateral sclerosis (ALS) form of the disease were found to have a disease-related mutation. One patient appears to have autosomal recessive adult-onset ALS associated with homozygosity for D90A and presents the characteristic phenotype of very slowly ascending paresis with both lower and upper motor neurone signs. Another patient, heterozygous for D90A, presents ALS with lumbar onset and rapid progression. This is the first report of a Cu,Zn SOD mutation in ALS in Russia.