Résumé
BACKGROUND: Down syndrome (DS) is the most common cause of mental retardation of genetic etiology with the prevalence rate of 1/700 to 1/1000 live births worldwide. Several polymorphisms in folate/homocysteine metabolism pathways genes have been reported as a risk factor in women for bearing DS child, but very few studies investigated these polymorphisms in DS cases whether there are a risk factor for being DS or not. OBJECTIVE: We have investigated the association of methylenetetrahydrofolate reductase (MTHFR) with the occurrence of DS in Indian population. MTHFR is one of the key regulatory enzymes involved in the metabolic pathway of homocysteine responsible for the reduction of methyltetrahydrofolate. A total of 32 DS cases and 64 age, sex matched controls were genotyped for MTHFR C677T polymorphism by polymerase chain reaction‑restriction fragment length polymorphism. RESULTS: The observed genotype frequencies were CC = 0.81; CT = 0.17 and TT = 0.02 in controls and CC = 0.81 and CT = 0.19 in DS cases. Frequency of T allele in DS and controls were 0.09 and 0.1, respectively. Significant difference in the distribution of mutant 677T allele was not observed between DS cases and controls (odds ratio = 0.915; 95% confidence intervals: 0.331-2.53; P = 0.864). CONCLUSION: Results of this study indicate that MTHFR C677T polymorphism is not risk factor for DS.
Sujets)
Sujet âgé , Méthylation de l'ADN/génétique , Syndrome de Down/épidémiologie , Femelle , Homocystéine , Humains , Inde , Mâle , Methylenetetrahydrofolate reductase (NADPH2)/génétique , Polymorphisme génétique/génétique , Facteurs de risqueRésumé
BACKGROUND AND OBJECTIVES: Methionine synthase reductase (MTRR) is a vital enzyme of homocysteine/methionine metabolic pathway and is required for the conversion of inactive form of methionine synthase (MTR) to its active form. A clinically important allelic variant of MTRR A66G, with less enzymatic activity is reported with worldwide prevalence rate of ~ 30%. The present study was designed to determine the frequency of MTRR A66G polymorphism in rural Sunni Muslim population of Eastern Uttar Pradesh. MATERIALS AND METHODS: Total 56 subjects were analyzed for MTRR A66G polymorphism. A66G mutation analysis was carried out according to the polymerase chain reaction-restriction fragment length polymorphism method of Wilson et al. [1] amplification with MTRR specific primers followed by amplicon digestion with NdeI enzyme was used for the identification of different MTRR genotypes in subjects. RESULTS AND DISCUSSION: The AA genotype was found in 5 subjects, AG in 23 subjects, and GG genotype in 28 subjects. Genotype frequencies of AA, AG, and GG were 0.089, 0.41, and 0.5 respectively. The allele frequency of A allele was found to be 0.298 and G allele was 0.705. CONCLUSION: It is evident from the present study that the percentage of homozygous genotype GG and frequency of G allele is high in the target Muslim population.
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Adolescent , Adulte , Sujet âgé , Allèles , Codes de déontologie , Éthique , Ferredoxine-NADP reductase/génétique , Fréquence d'allèle , Prédisposition génétique à une maladie , Génotype , Inde , Islam , Humains , Adulte d'âge moyen , Polymorphisme génétique , Polymorphisme de nucléotide simple , Groupes de population/génétiqueRésumé
Objective: This study was aimed to evaluate the Methionine synthase reductase (MTRR) A66G mutation in Yadav and Scheduled Caste (SC) population of Uttar Pradesh. Materials and Methods: Blood samples were collected from 100 subjects after taking informed written consent and PCR-RFLP method was used for the analysis of A66G mutation. After NdeI digestion, 66-bp amplicon of normal allele was cut into 22- and 44-bp long fragments, whereas mutant G allele was not digested. Results: Frequencies of genotypes in Yadav population AA, AG, and GG were 12%, 60%, and 28%, respectively, and in SC population, genotypic frequencies were 12% (AA), 52% (AG), and 36% (GG). Conclusion: MTRR gene A66G mutation is found to be polymorphic in both the target populations with G allele frequencies being 0.58 for Yadav and 0.62 for Scheduled Caste.
Résumé
AIM: This study was aimed to evaluate the 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in eastern Uttar Pradesh population. MATERIALS AND METHODS: Polymerase chain reaction (PCR) using specific primers followed by amplicon digestion by Hinf I restriction enzyme was used for MTHFR C677T polymorphism analysis. Total 250 subjects were analyzed. RESULTS: The CC genotype was found in 192 subjects, followed by CT in 56 subjects and TT in 2 subject. Genotype frequencies of CC, CT and TT were 0.768, 0.224 and 0.008, respectively. The frequency of C allele was found to be 0.88 and that of T allele was 0.12. CONCLUSION: It is evident from the results of the present study that the percentage of homozygous genotype (CC) is highest in the target population.
Sujets)
5,10-Methylenetetrahydrofolate reductase (FADH2)/génétique , Adolescent , Adulte , Sujet âgé , Homocystéine , Humains , Inde , Méthylation , Methylenetetrahydrofolate reductase (NADPH2)/génétique , Adulte d'âge moyen , Réaction de polymérisation en chaîne/méthodes , Polymorphisme génétique/génétique , PrévalenceRésumé
Objective : The aim of the present study was to investigate the distribution of methylenetetrahydrofolate reductase (C677T) polymorphism in the Muslim population of eastern Uttar Pradesh. Materials and Methods: Total 56 subjects were analysed for MTHFR C677T polymorphism. C677T mutation analysis was done according to the PCR-RFLP (Polymerase chain reaction-Restriction fragment length polymorphism) method. Results : The frequencies of three genotypes CC, CT, and TT were 0.857, 0.125, and 0.07, respectively, and the frequency of mutated T allele was found to be 0.080. Conclusion : Genotypes and allele frequencies revealed the low prevalence of MTHFR C677T polymorphism in Indian Muslims. C677T mutation has been suggested to be positively associated with the risk of several congenital and multifactorial disorders. The low frequency of T/T genotype in the Muslim population may be due to malnutrition in pregnant women, because of insufficient intake of folate is considered to be a survival disadvantage for foetuses with T/T genotype.
Sujets)
Femelle , Prédisposition génétique à une maladie/génétique , Génotype , Humains , Inde/épidémiologie , Islam , Methylenetetrahydrofolate reductase (NADPH2)/génétique , Polymorphisme de restriction , Polymorphisme génétique , Groupes de populationSujets)
Biopsie , Maladie de Bowen/diagnostic , Humains , Mâle , Adulte d'âge moyen , Peau/anatomopathologieSujets)
Anticorps antinucléaires/sang , Bras , Autoanticorps/sang , Autoantigènes/immunologie , Dos , Biopsie , Humains , Lichen scléroatrophique/complications , Mâle , Adulte d'âge moyen , Petites ribonucléoprotéines nucléaires/immunologie , Sclérodermie localisée/complications , Protéines coeur de snRNPRésumé
A 12-year-old boy born of a nonconsanguineous marriage presented with dry rough skin and photophobia since birth. His growth and developmental milestones were normal and there was no history of any neurological problem, hearing deficit or scarring around the hair follicles. Cutaneous examination revealed diffuse thinning of scalp hair with loss of eyebrows and eyelashes and a sandpapery texture of the skin all over the body, suggestive of ichthyosis follicularis with alopecia and photophobia syndrome.
Sujets)
Alopécie/complications , Enfant , Humains , Ichtyose/complications , Mâle , Photophobie/complications , SyndromeRésumé
BACKGROUND: Phototesting is an essential tool in the investigation of photodermatoses. AIMS: The main aim was to study the cutaneous response to UVR in terms of minimal erythema dose (MED) to both UVA and UVB in normal Indian subjects with a solar simulator and to study the relationship of skin type to MED. METHODS: One hundred healthy volunteers not on any medication and without any history of photodermatoses were phototested using a solar simulator with whole spectrum irradiation (UVA, UVB and visible light) and only visible and UVA radiation. The tested areas were marked with gentian violet and readings were taken after 24 hrs. RESULTS: Of the 100 volunteers, 48% were males and 52% were females, with a mean age of 36.6 +/- 11.6 yrs. The most common skin type among Indians was type 5 (46%) followed by type 4 (41%). The mean MED for UVB was 61.5 +/- 17.25 J/cm2. The MED for UVA could not be determined as none of the patients showed any erythema after irradiation for 45 minutes. CONCLUSIONS: As the MED is found to be low in idiopathic acquired photodermatoses, the MED in the normal population could serve as a baseline data in the investigation.