Abstract:
:Down syndrome is a complex genetic and metabolic disorder attributed to the presence of three copies of chromosome 21. The extra chromosome derives from the mother in 93% of cases and is due to abnormal chromosome segregation during meiosis (nondisjunction). Except for advanced age at conception, maternal risk factors for meiotic nondisjunction are not well established. A recent preliminary study suggested that abnormal folate metabolism and the 677C-->T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene may be maternal risk factors for Down syndrome. The present study was undertaken with a larger sample size to determine whether the MTHFR 677C-->T polymorphism was associated with increased risk of having a child with Down syndrome. Methionine synthase reductase (MTRR) is another enzyme essential for normal folate metabolism. A common polymorphism in this gene was recently associated with increased risk of neural tube defects and might also contribute to increased risk for Down syndrome. The frequencies of the MTHFR 677C-->T and MTRR 66A-->G mutations were evaluated in DNA samples from 157 mothers of children with Down syndrome and 144 control mothers. Odds ratios were calculated for each genotype separately and for potential gene-gene interactions. The results are consistent with the preliminary observation that the MTHFR 677C-->T polymorphism is more prevalent among mothers of children with Down syndrome than among control mothers, with an odds ratio of 1.91 (95% confidence interval [CI] 1.19-3.05). In addition, the homozygous MTRR 66A-->G polymorphism was independently associated with a 2. 57-fold increase in estimated risk (95% CI 1.33-4.99). The combined presence of both polymorphisms was associated with a greater risk of Down syndrome than was the presence of either alone, with an odds ratio of 4.08 (95% CI 1.94-8.56). The two polymorphisms appear to act without a multiplicative interaction.
journal_name
Am J Hum Genetjournal_title
American journal of human geneticsauthors
Hobbs CA,Sherman SL,Yi P,Hopkins SE,Torfs CP,Hine RJ,Pogribna M,Rozen R,James SJdoi
10.1086/303055subject
Has Abstractpub_date
2000-09-01 00:00:00pages
623-30issue
3eissn
0002-9297issn
1537-6605pii
S0002-9297(07)63249-2journal_volume
67pub_type
杂志文章abstract::The cloning of the CFTR gene has made it technically possible to avert the unwanted birth of a child with cystic fibrosis (CF). Several large trials offering prenatal CF carrier screening suggest that such screening is practical and that identified carriers generally use the information obtained. Therefore, a critical...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/302042
更新日期:1998-10-01 00:00:00
abstract::Blood pressure (BP) is a heritable risk factor for cardiovascular disease. To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP), we genotyped ~50,000 SNPs in up to 87,736 individuals of European ancestry and combined these in a meta-analy...
journal_title:American journal of human genetics
pub_type: 杂志文章,meta分析
doi:10.1016/j.ajhg.2013.12.016
更新日期:2014-03-06 00:00:00
abstract::Patients with Joubert syndrome 2 (JBTS2) suffer from a neurological disease manifested by psychomotor retardation, hypotonia, ataxia, nystagmus, and oculomotor apraxia and variably associated with dysmorphism, as well as retinal and renal involvement. Brain MRI results show cerebellar vermis hypoplasia and additional ...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2009.12.007
更新日期:2010-01-01 00:00:00
abstract::Using the technique of in vitro human-hamster fertilization, sperm of four men heterozygous for 4 reciprocal translocations--t(4;17),t(5;13),t(6;7), and t(9;18)--was studied. Frequencies of numerical abnormalities unrelated to the translocations range from 8.3% to 13.3%, and the incidence of imbalances ranges from 23....
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) syndrome is a rare, multisystem disorder characterized clinically by ptosis, progressive external ophthalmoplegia, gastrointestinal dysmotility, leukoencephalopathy, thin body habitus, and myopathy. Laboratory studies reveal defects of oxidative-phosphoryla...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/301979
更新日期:1998-08-01 00:00:00
abstract::We have isolated large numbers of human recombinants from a cosmid library constructed from an interspecific (hamster/human) somatic cell hybrid whose only human component is an intact chromosome 3. Unique sequence probes were isolated from these recombinants and were used to localize them along the length of chromoso...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1989-09-01 00:00:00
abstract::Protoporphyria is an autosomal dominant disease in man in which protoporphyrin accumulated because of a defect in heme synthase (ferrochelatase) activity. A disease has been described in cattle that has the same manifestations as does the human disease. We measured heme synthase activity in sonicates of cultured skin ...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1982-03-01 00:00:00
abstract::Multiple-synostosis syndrome is an autosomal dominant disorder characterized by progressive symphalangism, carpal/tarsal fusions, deafness, and mild facial dysmorphism. Heterozygosity for functional null mutations in the NOGGIN gene has been shown to be responsible for the disorder. However, in a cohort of six proband...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/503204
更新日期:2006-04-01 00:00:00
abstract::Progressive X-linked cone-rod dystrophy (COD1) is a retinal disease affecting primarily the cone photoreceptors. The COD1 locus originally was localized, by the study of three independent families, to a region between Xp11.3 and Xp21.1, encompassing the retinitis pigmentosa (RP) 3 locus. We have refined the COD1 locus...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/301667
更新日期:1998-01-01 00:00:00
abstract::Admixture mapping (also known as "mapping by admixture linkage disequilibrium," or MALD) provides a way of localizing genes that cause disease, in admixed ethnic groups such as African Americans, with approximately 100 times fewer markers than are required for whole-genome haplotype scans. However, it has not been pos...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/420856
更新日期:2004-05-01 00:00:00
abstract::Attention-deficit/hyperactivity disorder (ADHD) is the most commonly diagnosed behavioral disorder in childhood and likely represents an extreme of normal behavior. ADHD significantly impacts learning in school-age children and leads to impaired functioning throughout the life span. There is strong evidence for a gene...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/342732
更新日期:2002-10-01 00:00:00
abstract::About 20%-25% of Caucasian individuals are nonsecretors who fail to express soluble A, B, H, and Lewis b histo-blood group antigens in secretory organs and secretory fluids because of the absence of the Secretor gene (FUT2)-encoded alpha(1,2)-fucosyltransferase (Se enzyme) activity. Recently, the FUT2 and a pseudogene...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1996-08-01 00:00:00
abstract::The Huntington disease (HD) gene has been mapped to the most distal subband of chromosome 4p. Analysis of recombination events has not provided an unequivocal location of the HD gene, but it indicates a position very close to the telomere as one possibility. We have constructed a yeast artificial chromosome (YAC) vect...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1990-04-01 00:00:00
abstract::A non-Jewish family is presented in which the genes for Tay-Sachs disease and Sandhoff disease are segregating. Individuals heterozygous for both alleles have low serum and white cell total hexosaminidase levels together with a proportion of heat-labile hexosaminidase A (HEX A) which falls in the normal range. The ind...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1980-11-01 00:00:00
abstract::Cells derived from patients with the cancer-prone inherited disorder ataxia-telangiectasia (A-T) show an abnormal response to ionizing radiation-induced DNA damage, such as an increased cell killing and a diminished inhibition of DNA synthesis. The enhanced killing of A-T (group D) cells by X-rays can be corrected by ...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1995-02-01 00:00:00
abstract::We studied mutations in the mtDNA control region (CR) using deep-rooting French-Canadian pedigrees. In 508 maternal transmissions, we observed four substitutions (0.0079 per generation per 673 bp, 95% CI 0.0023-0.186). Combined with other familial studies, our results add up to 18 substitutions in 1,729 transmissions ...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/324024
更新日期:2001-11-01 00:00:00
abstract::Association studies are one of the major strategies for identifying genetic factors underlying complex traits. In samples of related individuals, conventional statistical procedures are not valid for testing association, and maximum likelihood (ML) methods have to be used, but they are computationally demanding and ar...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/513895
更新日期:1997-07-01 00:00:00
abstract::Subcutaneous adipose tissue stores excess lipids and maintains energy balance. We performed expression quantitative trait locus (eQTL) analyses by using abdominal subcutaneous adipose tissue of 770 extensively phenotyped participants of the METSIM study. We identified cis-eQTLs for 12,400 genes at a 1% false-discovery...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2017.01.027
更新日期:2017-03-02 00:00:00
abstract::The genetically inactive, late-replicating human female X chromosome can be effectively distinguished from its more active, earlier-replicating homologue, when cells are grown according to the appropriate BrdU-33258 Hoechst protocol. Results obtained from a fluorescence analysis of DNA replication in X chromosomes are...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1976-05-01 00:00:00
abstract::Age at onset of motor symptoms was collected on 611 persons affected with Huntington disease (HD) among 3,201 persons "at risk" in 108 kindreds. Life-table estimates correcting for truncated intervals of observation (censoring) produced a median age at onset 5 years older than the observed mean. Risk estimates of HD o...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1988-11-01 00:00:00
abstract::N-alpha-acetylation is a common co-translational protein modification that is essential for normal cell function in humans. We previously identified the genetic basis of an X-linked infantile lethal Mendelian disorder involving a c.109T>C (p.Ser37Pro) missense variant in NAA10, which encodes the catalytic subunit of t...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2018.03.004
更新日期:2018-05-03 00:00:00
abstract::A current approach to mapping complex-disease-susceptibility loci in genome-wide association (GWA) studies involves leveraging the information in a reference database of dense genotype data. By modeling the patterns of linkage disequilibrium in a reference panel, genotypes not directly measured in the study samples ca...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2009.01.013
更新日期:2009-02-01 00:00:00
abstract::It is generally accepted that the blood group subtypes A1 and A2 expressions are controlled by two different blood group N-acetylgalactosaminyl-transferases, that is, A1-enzyme and A2-enzyme, respectively, and that the two types of enzymes are governed by the allelic A1 and A2 genes. The observed frequencies of blood ...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1983-11-01 00:00:00
abstract::Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when delete...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2018.02.015
更新日期:2018-04-05 00:00:00
abstract::Duplications of proximal 15q have been found in individuals with autistic disorder (AD) and varying degrees of mental retardation. Often these abnormalities take the form of a supernumerary inverted duplicated chromosome 15, more properly described as an isodicentric chromosome 15, or idic(15). However, intrachromosom...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1997-04-01 00:00:00
abstract::Classical congenital muscular dystrophies (CMDs) are autosomal recessive neuromuscular disorders characterized by early onset of hypotonia and weakness, atrophy of limbs and trunk muscles, contractures, and dystrophic changes in the muscle biopsy. So far, only one gene, LAMA2 (6q2), which encodes the laminin alpha2 ch...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1086/301882
更新日期:1998-06-01 00:00:00
abstract::Genome-wide association studies (GWASs) have successfully identified thousands of genetic variants for many complex diseases; however, these variants explain only a small fraction of the heritability. Recently, genetic association studies that leverage external transcriptome data have received much attention and shown...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:10.1016/j.ajhg.2018.03.019
更新日期:2018-05-03 00:00:00
abstract::The estimate of heterozygosity and proportion of polymorphic loci for 33 red blood cell loci has been updated by the elimination of some loci of questionable status and the addition of data on 33 loci. The new figures for heterozygosity and proportion of polymorphic loci, .105 and .283, respectively, are based on 60 r...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1978-07-01 00:00:00
abstract::The National Research Council recommended the use of the ceiling principle in forensic applications of DNA testing on the grounds that the ceiling principle was believed to be "conservative," giving estimates greater than or equal to the actual genotype frequencies in the appropriate reference population. We show here...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1993-08-01 00:00:00
abstract::Linkage analyses were performed in 11 families with X-linked Menkes disease. In each family more than one affected patient had been diagnosed. Forty informative meioses were tested using 11 polymorphic DNA markers. From two-point linkage analyses high lod scores are seen for DXS146 (pTAK-8; maximal lod score 3.16 at r...
journal_title:American journal of human genetics
pub_type: 杂志文章
doi:
更新日期:1992-05-01 00:00:00