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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Congenital hypothyroidism is a relatively common endocrine disorder, affecting one in 4000 newborn infants. Undiagnosed and untreated congenital hypothyroidism will result in un-toward consequences, including mental retardation and other significant neurologic sequelae. For these reasons, programs to screen newborns were developed to detect congenital hypothyroidism before clinical features become obvious enough to suggest the diagnosis. The most common clinical features include prolonged jaundice, skin mottling, hypotonia, umbilical hernia, constipation, and macroglossia. Congenital hypothyroidism may be caused by several different disorders; ectopic thyroid glands represent the most common cause. There is accumulating evidence that autoimmune thyroid disease as manifested by TBII may be the cause of thyroid dysgenesis in some cases. The diagnosis is easily confirmed by finding a low serum free T4 or total T4 and elevated serum TSH concentration. The treatment of choice is levothyroxine; these infants must be followed carefully to ensure normal growth and development and maintenance of serum T4 and TSH within the normal ranges. With appropriate treatment and follow-up, the large majority of these infants have an excellent prognosis, with an IQ no different from comparison populations. However, it appears that there is still a small percentage of infants who are the most severely affected, who manifest the lowest serum T4 levels, thyroid aplasia, and retarded bone ages, and who may run the highest risk for some degree of retardation and other neurologic sequelae. Acquired hypothyroidism is also a relatively common disorder, occurring in one in 500 to one in 1000 school-age children. These children most commonly have a slowdown in growth, short stature, a goiter, and a drop in school performance. Other clinical features may be subtle or absent except in more severe or long-standing cases. The most common cause is chronic lymphocytic thyroiditis. The diagnosis is easily established by finding low serum-free T4 or total T4 and elevated serum TSH concentrations. Again, levothyroxine is the treatment of choice. With appropriate treatment and follow-up, all clinical features that develop after age 3 should be reversible and the prognosis should therefore be very good.
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PMID:Diagnosis and treatment of hypothyroidism in children. 331 7

In 1990, iodine deficiency affected almost one-third of the world population and was the greatest single cause of preventable brain damage and mental retardation. Following a resolution adopted by the World Summit for Children in 1990. major programmes of iodine supplementation were implemented by the governments of the affected countries with the support of major donors. Iodisation of salt was recognised as the method of choice. Nine years later, by April 1999, 75% of the affected countries had legislation on salt iodisation and 68% of the affected populations had access to iodised salt. The prevalence of iodine deficiency disorders decreased drastically in most countries and the deficiency disappeared completely in some such as Peru. This result constitutes a public heath success unprecedented with a non-infectious disease. However, occasional adverse effects occurred. The principle effect is iodine-induced hyperthyroidism which occurs essentially in older people with autonomous nodular goitres, especially following iodine intake that is too rapid and of too massive an increment. The incidence of the disorder is usually low and reverts spontaneously to the background rate of hyperthyroidism or even below this rate after 1 to 10 years of iodine supplementation. The possible occurrence of iodine-induced thyroiditis in susceptible individuals has not been clearly demonstrated by large epidemiological surveys. Iodine supplementation is followed by an increased prevalence of occult papillary carcinoma of the thyroid discovered at autopsy but the prognosis of thyroid cancer is improved due to a shift towards differentiated forms of thyroid cancer that are diagnosed at earlier stages. Iodine-induced hyperthyroidism and other adverse effects can be almost entirely avoided by adequate and sustained quality control and monitoring of iodine supplementation which should also confirm adequate iodine intake. Available evidence clearly confirms that the benefits of correcting iodine deficiency far outweigh the risks of iodine supplementation.
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PMID:Iodine supplementation: benefits outweigh risks. 1067 91

Enchondromas are a feature of several constitutional disorders of bone, and the classification of different nosologic entities is still provisional. Among these disorders, spondyloenchondrodysplasia (SPENCD), as outlined by Schorr et al. [1976], is defined by the presence of radiolucent spondylar and metaphyseal lesions that represent persistence of islands of chondroid tissue within bone. Careful review of radiographic findings is needed to distinguish SPENCD from the many other disorders combining enchondromas with spinal lesions. Even when strict criteria are applied, it appears that SPENCD is clinically heterogeneous, as some SPENCD patients are neurologically intact while others present with spasticity, mental retardation, and cerebral calcifications in different combinations, and it has been suggested that SPENCD should be divided in two types. We herein report ten individuals from six families with SPENCD and illustrate the radiographic changes. Seven individuals had CNS manifestations including spasticity, developmental delay, and late-onset cerebral calcifications. We also noted that six individuals had clinical manifestations of autoimmunity (auto-immune thrombocytopenic purpura, auto-immune hemolytic anemia, auto-immune thyroiditis, and SLE) and one had been diagnosed with immune deficiency. Neurological and autoimmune manifestations were seen in different combinations within one single family. These observations suggest that SPENCD may be a single entity defined by specific radiographic features, but with remarkably pleiotropic manifestations that include CNS disease (spasticity, mental retardation, and calcifications), as well as immune dysregulation ranging from autoimmunity to immunodeficiency. The notion of recessive inheritance hitherto assumed is challenged by the observation of two apparently dominant pedigrees.
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PMID:Spondyloenchondrodysplasia with spasticity, cerebral calcifications, and immune dysregulation: clinical and radiographic delineation of a pleiotropic disorder. 1647 Jun

Thyroid hormones are vital for the proper functioning of the female reproductive system, since they modulate the metabolism and development of ovarian, uterine, and placental tissues. Therefore, hypo- and hyperthyroidism may result in subfertility or infertility in both women and animals. Other well-documented sequelae of maternal thyroid dysfunctions include menstrual/estral irregularity, anovulation, abortion, preterm delivery, preeclampsia, intrauterine growth restriction, postpartum thyroiditis, and mental retardation in children. Several studies have been carried out involving prospective and retrospective studies of women with thyroid dysfunction, as well as in vivo and in vitro assays of hypo- and hyperthyroidism using experimental animal models and/or ovarian, uterine, and placental cell culture. These studies have sought to elucidate the mechanisms by which thyroid hormones influence reproduction to better understand the physiology of the reproductive system and to provide better therapeutic tools for reproductive dysfunctions that originate from thyroid dysfunctions. Therefore, this review aims to summarize and update the available information related to the role of thyroid hormones in the morphophysiology of the ovary, uterus, and placenta in women and animals and the effects of hypo- and hyperthyroidism on the female reproductive system.
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PMID:Thyroid hormones and female reproduction. 2976 91