Mucopolysaccharidosis Type I in the Russian Federation and Other Republics of the Former Soviet Union: Molecular Genetic Analysis and Epidemiology.

Mutations in the IDUA gene cause deficiency of the lysosomal enzyme alpha-l-iduronidase (IDUA), which leads to a rare disease known as mucopolysaccharidosis type I. More than 300 pathogenic variants of the IDUA gene have been reported to date, but not much is known about the distribution of mutations in different populations and ethnic groups due to the low prevalence of the disease. This article presents the results of a molecular genetic study of 206 patients with mucopolysaccharidosis type I (MPS I) from the Russian Federation (RF) and other republics of the former Soviet Union. Among them, there were 173 Russian (Slavic) patients, 9 Tatars, and 24 patients of different nationalities from other republics of the former Soviet Union. Seventy-three different pathogenic variants in the IDUA gene were identified. The common variant NM_000203.5:c.208C>T was the most prevalent mutant allele among Russian and Tatar patients. The common variant NM_000203.5:c.1205G>A accounted for only 5.8% mutant alleles in Russian patients. Both mutations were very rare or absent in patients from other populations. The pathogenic variant NM_000203.5:c.187C>T was the major allele in patients of Turkic origin (Altaian, Uzbeks, and Kyrgyz). Specific own pathogenic alleles in the IDUA gene were identified in each of these ethnic groups. The identified features are important for understanding the molecular origin of the disease, predicting the risk of its development and creating optimal diagnostic and treatment tools for specific regions and ethnic groups.

Case report: a rare case of Hunter syndrome (type II mucopolysaccharidosis) in a girl.

BACKGROUND: Hunter syndrome (mucopolysaccharidosis type II) is a recessive X-linked disorder due to mutations in the iduronate 2-sulfatase (IDS) gene. The IDS gene encodes a lysosomal enzyme, iduronate 2-sulfatase. The disease occurs almost exclusively in males. However, in the literature, 12 cases of the disease in females are known due to structural anomalies, a non-random chromosome X inactivation or chromosome X monosomy. The purpose of this article is to demonstrate a rare case of Hunter syndrome in a girl caused by a mutation in the IDS gene inherited from the mother and the presence of chromosome X of paternal origin, partially deleted in the long arm region - 46,X,del(X)(q22.1). CASE PRESENTATION: Girl M., 4 years old, entered the hospital with growth retardation, pain in the lower limbs, and joint stiffness, noted from the age of 18 months. After the karyotype analysis, which revealed a partial deletion of the long arm of chromosome X - 46, X, del (X) (q 22.1), Turner syndrome was diagnosed. However, due to the hurler-like facial phenotype, Hurler syndrome or type I mucopolysaccharidosis (MPS) was suspected. The study of lysosomal enzymes showed normal alpha-L-iduronidase activity and a sharp decrease in the activity of iduronate sulfatase in the blood: 0.001 µM/l/h, at a rate of 2.5-50 µM/l/h. Molecular genetic analysis revealed a hemizygous deletion in the IDS gene, which was not registered in the international Human Gene Mutation Database (HGMD) professional. This deletion was not detected in the girl's father, but was detected in her mother in the heterozygous state. CONCLUSIONS: Thus, the girl confirmed comorbidity - Turner syndrome with a partial deletion of the long arm of chromosome X of paternal origin, affecting the Xq28 region (localization of the IDS gene), and Hunter syndrome due to a deletion of the IDS gene inherited from the mother. The structural defect of chromosome X in the girl confirmed the hemizygous state due to the mutation in the IDS gene, which has led to the formation of the clinical phenotype of Hunter syndrome.

[The 444G/A and -1021 C/T polymorphisms of the dopamine-beta-hydroxylase gene modulate the trajectory of alcohol dependence development].

AIM: To study the influence of 444 G/A (rs 1108580) and -1021 C/T (rs 1611115) polymorphisms of the dopamine beta-hydroxylase (DBH) gene on clinical parameters of the trajectory of alcohol dependence. MATERIAL AND METHODS: Authors studied 548 male inpatients, of Slavic ethnicity, with ICD-10 diagnosis of «alcohol dependence¼ (F-10.2). RESULTS: The effects of DBH * 444 G/A on the rate of formation of alcohol withdrawal syndrome (AWS), and DBH *-1021C/T on the age of onset of alcohol abuse with significant role of the age of first alcohol use were identified. In 444 G/A GG carriers, the development of AWS was accelerated since the beginning of alcohol abuse compared with AA carriers (p=0.026), AG carriers occupied an intermediate position. In 22.5% of GG carriers, AWS developed within 2 years (AA: 8.11%, p=0.005; AG: 17.67%, p=0.04). According to the results of linear regression analysis, in AG carriers the alcohol abuse (p=0.037) and the AWS (p=0.049) developed earlier than in AA carriers if the first alcohol use occured at the age of about 15 years. Among -1021C/T genotype carriers who began to abuse alcohol at an early age (before 20 years), there were 23.45% patients with CC genotype and only 11.97% with a T allele (genotypes CT+TT) (p=0.03), but T carriers began to abuse alcohol earlier than others (p=0.05) if the first alcohol use occurred at the age of about 16 years. CONCLUSION: The results can be used to search for genetic markers for prognosis of alcohol dependence development.

[Duration of therapeutic remission alcohol dependence: a role of dopamine system genes polymorphism and family history density]. / Dlitel'nost' terapevticheskoi remissii u bol'nykh s alkogol'noi zavisimost'iu: rol' polimorfizma genov dofaminovoi sistemy i stepeni semeinoi otiagoshchennosti.

AIM: A quantitative assessment of the impact of genetic factors (density of family history of alcohol dependence and dopamine system genes polymorphisms) on the average time to relapse (ATR) after alcohol dependence treatment (duration of therapeutic remission from alcohol dependence). MATERIAL AND METHODS: Authors studied 247 male Russian inpatients diagnosed with ICD-10 F10.2 who had at least two therapeutic remissions before the current hospitalization and 259 healthy controls. ATR and the density of family history of alcohol dependence were evaluated retrospectively according to the clinical interview. RESULTS AND CONCLUSION: The high density of family history (at least 2 people with alcohol problems among the blood relatives) and some dopamine system genes polymorphisms significantly affect the average time to relapse. An allele A9 of the dopamine transporter gene (DAT VNTR 40 bp) was associated (p=0.003; OR=1.73) with short (up to 12 months) average time to relapse. A trend toward association (p=0.052) was noted for dopamine receptor type 2 gene polymorphisms (rs1800497, rs6275). Patients with long-term ATR are genetically different from patients with short ATR by the set of variants of tyrosine hydroxylase gene (HUMTH01, p=0.002; OR=3.08) and from the control group by the genotype LH of the catechol-O-methyltransferase gene (rs4680, p=0.02; OR=2.33). Some other sets of HUMTH01 variants (p=0.0001; OR=2.38) and the dopamine receptor type 4 (DRD4 VNTR 48 bp, p=0.055) may have protective properties with regard to short ATR. Polymorphisms (rs1108580, rs1611115) of the dopamine-beta-hydroxylase gene were not related to the ATR.

[Association study of the Val158Met polymorphism of the catechol-O-methyltransferase gene and alcoholism and heroin dependence: the role of a family history].

The aim of this study was to investigate the association the Val158Met polymorphism of the catechol-O-methyltransferase (COMT) gene and predisposition to alcoholism and heroin dependence. The authors genotyped DNA samples from 964 Russian males (395 alcoholics, 243 heroin addicts and 326 healthy controls). The association between the Val158Met COMT polymorphism and alcoholism was found in males with high density of family history (two or more blood relatives with alcoholism within the family). In this group, the frequency of a L (Met) allele was significantly higher in comparison with controls (p=0,001), patients without family history (p=0,034) and patients with the mild density of family history (p=0,0005). The frequency of the HH (ValVal) genotype was reduced as well compared to the controls (p=0,003). In the group of heroin addicts with the mild density of family history, there was a trend to lower frequency of the HH genotype (p=0,058) compared to patients without family history. The results suggest that the functional Val158Met COMT polymorphism is one of the significant markers of genetic predisposition to addiction diseases.

Analysis of cell-free fetal DNA in plasma and serum of pregnant women.

Sixty blood samples from pregnant women during gestational weeks 9-28 were investigated. Cell-free fetal DNA was extracted from maternal plasma or serum to be detected by nested PCR for determination of fetal gender. The SRY gene as a marker for fetal Y chromosome was detected in 34/36 women carrying a male fetus. In 3/24 women carrying female fetuses, the SRY sequence was also detected. Overall, fetal sex was correctly predicted in 91.7% of the cases. Therefore, the new, non-invasive method of prenatal diagnosis of fetal gender for women at risk of producing children with X-linked disorders is reliable, secure, and can substantially reduce invasive prenatal tests.

[Identification of mutations in the arylsulfatase B gene in Russian mucopolysaccharidosis type VI patients]. / Identifikatsiia mutatsii v gene arilsul'fatazy B u Rossiiskikh bol'nykh s mukopolisakharidozom tipa VI.

Molecular genetic analysis of the gene for arylsulfatase B (ASB) was conducted in ten Russian patients with type VI mucopolysaccharidosis (MPS VI) of different severity. Eight exons from the translated region of the ASB gene of each patient were amplified and sequenced using the nonradioactive method. Fourteen mutant alleles were identified in the sample studied by means of DNA analysis; 13 of them had not been described before. All patients except for one, who was an offspring of a consanguineous marriage, were genetic compounds with respect to the mutations found. Polymorphic sites A/G 1072 and A/G 1126, which were earlier revealed in exon 5 of the ASB gene, were found in five out of ten patients studied. The spectrum of mutant alleles of the ASB gene was highly specific and agreed with the characteristics of the population genetic load.

Novel type of genetic rearrangement in the iduronate-2-sulfatase (IDS) gene involving deletion, duplications, and inversions.

We describe a novel type of complex genetic rearrangement in the iduronate-2-sulfatase (IDS) gene of a severely affected MPSII patient. Southern blot analysis indicated an intragenic deletion of exons 5 and 6. The deletion spans 5,581 bp. Sequencing of the deletion junctions revealed a complex rearrangement involving duplications and inversions. A remaining 20 bp fragment (c) from the intron 6 sequence and two duplicated IDS gene fragments of 314 bp (a) from intron 6/exon 7 boundary and 23 bp (b) from exon 7 were found between the deletion breakpoints. Fragments a and c were placed in an inverted orientation. We suggest that the described rearrangement is a result of a nonhomologous recombination event at sites with little homology. The proposed model explaining this recombinational event involves the formation of "tetra-loop" single-stranded DNA structure during replication. The complexity of the described rearrangement and the lack of large homologous sequences at the mutational breakpoints suggest that complex molecular intermediates are formed during illegitimate recombination.

[Program for diagnosis and prevention of inherited metabolic diseases of cellular organelles]. / Prgramma diagnostiki i profilaktiki nasledstvennykh boleznei obmena kletochnykh organell.

A programme for diagnosis and prevention of lysosomal, peroxisomal, and mitochondrial [respiratory chain diseases (RCD)] diseases was developed on clinical, biochemical, and molecular approaches. The authors made postnatal diagnosis was made in 674 patients from 516 families and prenatal diagnosis in 124 fetuses in 94 families at risk. DNA analysis of mutant alleles in the mucopolysaccharidoses (MPS) I, II, and VI revealed 14, 13, and 4 new mutant alleles in IDS, ASB, IDUA genes, respectively. The pressure of a mutation process played a major role in the distribution of mutant alleles leading to MPS I and VI, but along with this factor genetic drift and migration undoubtedly influenced the observed spectrum of IDUA alleles in Russia. A clinical phenotype of patients with different MPS was analyzed on the basis of uniform registration of 167 symptoms and signs in 249 patients. Special statistical approaches were developed to characterize early manifestations of different MPS and "unique" signs and symptoms for many of them and "phenotypic distances" between them. The similar problems were solved for RCD through uniform registration of 110 symptoms and signs in 54 patients with different syndromes: pathognomonic symptoms for the whole RCD and "unique" symptoms for syndromes were defined.

Molecular genetics of mucopolysaccharidosis type I: mutation analysis among the patients of the former Soviet Union.

Mucopolysaccharidosis type I (MPS-I) is an autosomal recessive lysosomal storage disorder resulting from a deficiency of the lysosomal protein alpha-l-iduronidase (IDUA). Patients present within a broad spectrum of phenotypes from severe (Hurler syndrome) to clinically less severe (Scheie syndrome). Since 1982 a special program for the diagnosis and prevention of lysosomal storage diseases has operated in the former Soviet Union (FSU). We report the genotypes of 25 MPS-I patients with different clinical severities from the FSU. All the patients were screened for two common mutations (W402X and Q70X) and four other mutations (P533R, R89Q, A327P, 474 2a-->g). W402X and Q70X alleles accounted for 4 and 44%, respectively. Using SSCP analysis and subsequent direct sequencing we also detected four novel mutations (P533L, Q63X, Y343X, and A75P) in the IDUA gene, together with two mutations (974ins12bp, 134del12bp) described elsewhere. All were found in the heterozygous form in MPS-I patients with different clinical severities. A total of 32 mutant alleles leading to MPS-I was identified with nine patients fully genotyped. Four patients were homozygous for Q70X while five others were genetic compounds. Besides the eight identified mutations, six known polymorphisms were found. The spectrum of mutant alleles discovered is highly specific and proves the peculiarity of genetic loads in the FSU. Our data suggest a closer relationship between the FSU and Scandinavian populations than with Western and Central European populations.

Mutational spectrum of the iduronate-2-sulfatase (IDS) gene in 36 unrelated Russian MPS II patients.

We present a mutational analysis of the iduronate-2-sulfatase (IDS) gene of 36 Russian patients with Hunter syndrome. Among 29 mutant alleles, there were 19 missense mutations, 1 nonsense mutation, 6 mutations affecting splice sites, and 3 major structural alterations resulting in deletions. Of the 25 different mutations, 15 are novel and unique. Most of the missense mutations result in intermediate or severe phenotypes.

Identification of 9 novel IDS gene mutations in 19 unrelated Hunter syndrome (mucopolysaccharidosis Type II) patients. Mutations in brief no. 202. Online.

Hunter syndrome is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The IDS deficiency can be caused by several different types of mutations in the IDS gene. We have performed a molecular and mutation analysis of a total 19 unrelated MPS II patients of different ethnic origin and identified 19 different IDS mutations, 9 of which were novel and unique. SSCP analysis followed by DNA sequencing revealed four novel missense mutations: S143F, associated with the 562C-->T polymorphism, C184W, D269V and Y348H. Two novel nonsense mutations were found: Y103X (433C-->A) and Y234X (826C-->G). In two patients two novel minor insertions (42linsA and 499insA) were identified. In one patient a complete IDS deletion was found, extending from locus DXS1185 to locus DXS466).

Postnatal and prenatal diagnosis of lysosomal storage diseases in the former Soviet Union.

Diagnosis and prevention of lysosomal storage diseases (LSD) in the former Soviet Union (FSU) is based on the interaction of various local counselling units with the Department of Inherited Metabolic Diseases (DIMD) at the Research Center of Medical Genetics (RAMS). Work began in 1982 using standard, as well as newly developed biochemical techniques. 25 different LSD were diagnosed in 445 patients from 404 families. 106 pregnancies in families at risk were monitored prenatally, and 25 affected fetuses were diagnosed and aborted. The clinical spectrum of diagnosed lysosomal storage diseases (LSD) was surprisingly heterogeneous. Besides classical forms of LSD numerous atypical forms were discovered. They included juvenile and adult forms of some sphingolipidoses manifesting as progressive dystonia, spinocerebellar degeneration and hebephrenic schizophrenia, as well as an atypical form of mucolipidosis III in which the clinical phenotype bore an obvious resemblance to that of mucopolysaccharidosis (MPS) VI. The incidence of MPS was much higher than that of other LSD. It was evaluated as 1:15000 for two regions of the FSU. This investigation revealed some peculiarities of the ethnic distribution of MPS in populations of the FSU and supported the high prevalence of the gene for Tay-Sachs disease gene in Ashkenazi Jews.

Four novel mutant alleles of the arylsulfatase B gene in two patients with intermediate form of mucopolysaccharidosis VI (Maroteaux-Lamy syndrome).

Mucopolysaccharidosis type VI (MPSVI, Maroteaux-Lamy syndrome) is a lysosomal storage disease for which multiple clinical phenotypes have been described. A deficiency of the enzyme arylsulfatase B (ASB, N-acetylgalactosamine-4-sulfatase) is the cause of this autosomal recessively inherited disorder. The genotypes of two patients with an intermediate form of MPSVI have been determined by polymerase chain reaction (PCR) amplification of the entire open reading frame of the ASB gene and subsequent direct sequencing of both strands of the PCR fragments by an automated nonradioactive approach. In patient A, a C to T transition in allele I resulting in an exchange of the Arg codon 160 for a premature stop codon (R160*, exon 2), and a G to A transition in allele II leading to a Gln to Arg160 substitution (R160Q, exon 2) were detected. Patient B exhibited a 7-bp deletion in exon 1 of allele I resulting in a frame shift and a premature stop codon 33 triplets 3' of the site of deletion (delta G237-C243), and a C to T transition in allele II giving rise to a Trp to Arg152 substitution (R152W, exon 2). None of these four mutant alleles was present among 60 alleles of the ASB gene in unrelated controls, indicating that the former are not polymorphisms. These results emphasize the broad molecular heterogeneity of Maroteaux-Lamy syndrome and contribute to the establishment of a genotype/phenotype correlation in this disease.

[A PCR-system of analyzing polymorphic markers in gamma-A and gamma-G globin genes and gene for human blood coagulation factor IX with an internal control of the completeness of restriction hydrolysis]. / PTsR-sistemy analiza polimorfnykh markerov v gamma-A i gamma-G globinovykh genakh i gene faktora koaguliatsii krovi IX cheloveka s vnutrennim kontrolem polnoty restriktsionnogo gidroliza.

New systems are proposed for the PCR analysis of HindIII polymorphic sites in the gamma A and gamma G globin genes and of TaqI polymorphic site in the human factor IX gene of blood population. DNA fragments amplified according to the systems described contain constant restriction site of the appropriate endonuclease, in addition to the polymorphic one, which significantly improves the reliability of the RELP analysis. The systems proposed are highly specific and may be used for DNA diagnosis of beta-thalassemia and haemophilia B.