Occurrence Of Down Syndrome Research Articles

ABNORMAL FOLIC ACID HOMOCYSTEINE METABOLISM AS MATERNAL RISK FACTORS FOR DOWN SYNDROME IN JAPAN

Department of Public Health, Department of Pediatrics, Department of Molecular Epidemiology, Biostatistics Section and Department of Molecular Medicine,Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan Background: Japan has been considered as «a folate sufficient area», since traditional Japanese food contains an adequate amount of folic acid. However, the recent westernized food style of young Japanese mothers may affect the intake of folic acid among them. This food style may contribute to the occurrence of Down syndrome, which has proved to be linked to abnormal folate and homocysteine metabolisms. Aim of the study: To preliminary evaluate the levels of folic acid, homocysteine and other relevant factors which are associated with folate metabolism, among Japanese women who had pregnancies affected by Down syndrome. Methods: Blood samples from 31 women who had pregnancies affected by Down syndrome (DS) were obtained. 60 age-matched control blood samples were also obtained from mothers who had not experienced miscarriages or abnormal pregnancies

Abnormal folic acid-homocysteine metabolism as maternal risk factors for Down syndrome in Japan.

Japan has been considered as "a folate sufficient area", since traditional Japanese food contains an adequate amount of folic acid. However, the recent westernized food style of young Japanese mothers may affect the intake of folic acid among them. This food style may contribute to the occurrence of Down syndrome, which has proved to be linked to abnormal folate and homocysteine metabolisms. To preliminarily evaluate the levels of folic acid,homocysteine and other relevant factors which are associated with folate metabolism, among Japanese women who had pregnancies affected by Down syndrome. Blood samples from 31 women who had pregnancies affected by Down syndrome (DS) were obtained. 60 age-matched control blood samples were also obtained from mothers who had not experienced miscarriages or abnormal pregnancies (CONT). Plasma homocysteine and serum folic acid, vitamin B12, and B6 were measured and compared between DS and CONT. Furthermore, the frequency of MTHFR polymorphism (C677T) was also investigated. Plasma levels of homocysteine were significantly increased in DS mothers (p = 0.004). In contrast, serum levels of folic acid were significantly decreased in DS mothers (p = 0.0001). There were no significant differences in the vitamin B12 and B6 levels between DS and CONT. Also, the frequency of 5,10-methylenetetrahydrofolate reductase gene (MTHFR) homozygous polymorphism showed no differences between DS and CONT. Different levels of serum folic acid and plasma homocysteine between both groups may contribute to the occurrence of Down syndrome even in Japan. Although there was no significant difference in the frequency of MTHFR polymorphism between the groups, probably because of an inadequate number of samples, further studies may contribute to the understanding of the occurrence of Down syndrome in Japan.

Reproductive outcome according to semen quality in couples with infertility problems

Reproductive outcome according to semen quality in couples with infertility problems

Oxidative stress and neural dysfunction in Down syndrome.

Total or partial trisomy of chromosome 21 occurs with relatively high frequency and is responsible for the occurrence of Down syndrome. Phenotypically, individuals with Down syndrome display characteristic morphological features and a variety of clinical disorders. One of the challenges for researchers in this field has been to ascertain and understand the relationship between the Down syndrome phenotype with the gene dosage effect resulting from trisomy of chromosome 21. Much attention therefore, has been given towards investigating the consequences of overexpressing chromosome 21-linked genes. In particular, an extensive analysis of SOD1 and APP have provided important insights as to how perturbations in the expression of their respective genes may contribute to the Down syndrome phenotype. In this review we will highlight studies which support a key role for SOD1 and APP in the pathogenesis of neural abnormalities observed in individuals with Down syndrome. Central to this relationship is how the redox state of the cell is affected and its consequences to neural function and integrity.

Down Syndrome Complicated by Hemoglobin S/Beta+ Thalassemia

The chance occurrence of Down syndrome and sickle cell disease is an extremely rare event. The patient presented in this article is the only reported case, based on medical literature review, of Down syndrome coexisting with sickle cell disease due to hemoglobin S/beta+ thalassemia. He had multiple recurrent aplastic crises and severe psychomotor and growth retardation. The physiologic basis for the atypical manifestations of both of his disorders is the subject of this report.

Occurrence of down syndrome and human sexual behavior.

We analyzed the sexual habits of 80 mothers of normal children and of 33 mothers of children with the Down syndrome (DS). The data were obtained through the psychological interview technique. Unusually long intervals between intercourse at the time of conception were reported more frequently by mothers of DS children. Independent of the mother's age there was an association between the incidence of DS and long intervals between intercourse.