Association of interleukin 4 and MTHFR gene polymorphisms with distal symmetrical polyneuropathy in young diabetics.

Background:  It is believed that genetic factors play a role in the development and severity of neural injury among people with distal symmetrical polyneuropathy (DSP), because some genes are involved in specific biological pathways, acting in different ways in the pathogenic process.

Objective:  To identify potential associations involving the ( C677T) and ( intron 3 variable number of tandem repeats [I3VNTR]) gene polymorphisms and DSP in the studied sample.

Methods:  In total, 70 children and adolescents with type-1 diabetes underwent a nerve conduction studie (NCS) of the sural nerve.

Mothers of children with Down syndrome: a clinical and epidemiological study.

Down syndrome is the main genetic cause of intellectual disability. Many studies describe the clinical characteristics of DS patients; however, few have investigated the clinical profile of mothers who have children with DS. Advanced maternal age (≥ 35 years old) is a risk factor for DS.

Aurora kinase genetic polymorphisms: an association study in Down syndrome and spontaneous abortion.

Aneuploidies, such as Down syndrome (DS), are the leading cause of pregnancy loss. Abnormalities in aurora kinase proteins result in genomic instability and aneuploidy, mainly in tumors. Thus, polymorphisms in Aurora kinase genes could influence the occurrence of DS and spontaneous abortion.

Dihydrofolate Reductase (DHFR) del19bp Polymorphism and Down Syndrome Offspring.

Down syndrome (DS) is the most common form of mental disability of genetic etiology. Nondisjunction of chromosome 21 is the leading cause of the syndrome. In general, free trisomy 21 cases originate from missegregation in maternal meiosis.

DNA (cytosine-5)-methyltransferase 3B () polymorphism and risk of Down syndrome offspring.

Down syndrome (DS) is the most common form of human genetic mental retardation. Several polymorphisms in genes coding folic acid cycle enzymes have been associated to the risk of bearing a DS child; however, the results are controversial. S-adenosyl-l-methionine (SAM) is an important intermediate of folic acid pathway and acts as methyl donor and substrate for DNA (cytosine-5)-methyltransferase 3B ( - EC 2.

Molecular analysis of holoprosencephaly in South America.

Holoprosencephaly (HPE) is a spectrum of brain and facial malformations primarily reflecting genetic factors, such as chromosomal abnormalities and gene mutations. Here, we present a clinical and molecular analysis of 195 probands with HPE or microforms; approximately 72% of the patients were derived from the Latin American Collaborative Study of Congenital Malformations (ECLAMC), and 82% of the patients were newborns. Alobar HPE was the predominant brain defect in almost all facial defect categories, except for patients without oral cleft and median or lateral oral clefts.

Betaine-homocysteine methyltransferase 742G>A polymorphism and risk of down syndrome offspring in a Brazilian population.

Down syndrome (DS) is the most common form of mental retardation of genetic etiology. Several polymorphisms in genes involved with the folic acid cycle have been associated to the risk of bearing a DS child; however, the results are controversial. Betaine-homocysteine methyltransferase (BHMT) is a key enzyme of folate pathway, and catalyzes the remethylation of homocysteine into methionine.

Association of methylenetetrahydrofolate reductase gene 677C > T polymorphism and Down syndrome.

The association between Down syndrome (DS) and maternal polymorphisms in genes encoding folic acid metabolizing enzymes remains a controversial issue. A meta-analysis was performed to evaluate the association of maternal MTHFR 677C > T polymorphism and the risk of having a child with DS. Case-control studies were screened from major literature databases.

MTRR 66A>G polymorphism as maternal risk factor for Down syndrome: a meta-analysis.

Down syndrome (DS) is the most common cause of mental retardation. Recent reports have investigated possible genetic factors that may increase maternal risk for DS. Methionine synthase reductase (5-methyltetrahydrofolate-homocysteine methyltransferase reductase MTRR) plays an important role in folic acid pathway and a common polymorphism (c.

Beare-Stevenson cutis gyrata syndrome: A new case of a c.1124C↷G (Y375C) mutation in the FGFR2 gene.

Beare-Stevenson syndrome (BSS) (MIM#123790) is a rare disorder characterized by craniofacial anomalies and cutis gyrata associated with anogenital anomalies and prominent umbilical stump. There are few reports on the syndrome, and molecular analysis has revealed the involvement of two closely spaced mutations within the FGFR2 gene: c.1115C↷G (p.

No association of the polyhistidine tract polymorphism of the ZIC2 gene with neural tube defects in a South American (ECLAMC) population.

The ZIC genes comprise a family of transcriptional factors associated with neural tube defects (NTDs) in mice and with holoprosencephaly in humans. An allelic variant of ZIC2, a CAC repeat within the first exon, was reported in association with an increased risk of non-syndromic NTDs in patients with a Hispanic ethnic background. We investigated whether this 10-residue histidine tract polymorphism of the ZIC2 gene (c.

Second case of Beare-Stevenson syndrome with an FGFR2 Ser372Cys mutation.

Beare-Stevenson syndrome is characterized by cutis gyrata, acanthosis nigricans, skin furrows, skin tags, craniosynostosis, Crouzonoid-like features in some cases and cloverleaf skull in others, anogenital anomalies, and prominent umbilical stump. Reported causes are an FGFR2 Tyr375Cys mutation in nine cases and an FGFR2 Ser372Cys mutation in one case. Here, we report on a second patient with the FGFR2 Ser372Cys mutation.

Genetic polymorphism of MJD1 alleles and molecular analysis of SCA3 patients from Rio de Janeiro, Brazil.

Spinocerebellar ataxia type 3 is the most common form of autosomal dominant cerebellar ataxia. It is a severe progressive neurological disorder caused by an expansion of an exonic CAG repeat of the MJD1 gene. The repeated sequence is polymorphic among both normal individuals and patients.

Premature ovarian failure and FRAXA premutation: Positive correlation in a Brazilian survey.

Fragile X syndrome (FRAXA) is the most common form of inherited mental retardation (MR). The mutational mechanism leading to the disease involves an expansion of a trinucleotide repeat located at the 5' UTR region of the gene FMR-1. Four types of alleles can be identified in the population, based on the number of repeats: normal (6-40), gray-zone (41-60), premutated (61-200), and fully mutated (>200).

Genetic polymorphism at spinocerebellar ataxia 1 and 2 loci in Brazil.

Dynamic mutation involves the expansion of a tandem arrayed DNA sequence that is polymorphic in the population. This mechanism is associated with neurological/neuromuscular disorders and the pathology depends on the extension of the repeated tract, with a specific threshold for each disease. We made a PCR-based characterization of allelic polymorphism of SCA1 and SCA2 loci in a sample of 200 pairs of chromosomes in a population in Rio de Janeiro and found 23 different alleles at the SCA1 locus, varying from 10 to 39 CAG repeats (mean 27.

Dynamic mutation and human disorders: the spinocerebellar ataxias (review).

A completely new mutational event associated with human diseases - the dynamic mutation - was discovered in the last decade. The molecular mechanism underlying dynamic mutation involves the expansion and intergenerational instability of a tandem-arrayed nucleotide sequence that acquire a pathological size, despite its polymorphic occurrence in normal individuals. To date, at least fourteen neurological disorders are associated with this phenomenon, including Huntington's disease (HD), dentatorubral and palidoluysian atrophy (DRPLA), spinobulbar and muscular atrophy (SBMA), myotonic dystrophy (DM), fragile X syndrome, FRAXE mental retardation and spinocerebellar ataxias (SCA) types 1-3, 6-8, 12 and 17.