Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The fragile X [fra(X)] syndrome is the most common inherited form of X-linked mental retardation and is associated with a rare folate sensitive fragile site on the X chromosome at band Xq27.3. Recently, a common fragile site located at chromosome band Xq27.2 was delineated (Sutherland & Baker 1990). In order to confirm the previous findings and to further investigate the conditions required for induction of both types of fragile sites, we studied the use of four experimental protocols. Samples from a control male, two fra(X) males and a fra(X) carrier female were studied. Both common and rare fragile sites were seen in the samples from the fra(X) subjects. Up to 4% of cells showed both common and rare fragile sites on the same X chromosome at the 500 band level. The rare and common fragile sites on the X chromosome could be clearly distinguished. From 1 to 3% of the control cells exhibited the common fragile site, while none exhibited the rare fragile site. These protocols should be useful in resolving questionable fra(X) syndrome diagnoses.
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PMID:Simultaneous expression of the rare and common fragile sites on the X chromosome. 183 37

In this study we report the results of a systematic etiological, clinical genetic study in 307 institutionalized mentally retarded adult males. Special attention is paid to the nosology of X-linked mental retardation. During the survey 63 males with one or more 'Martin Bell'-like features were identified in whom repetitive fragile Xq27-3 screenings were negative. In 13 of them, belonging to 9 different families, pedigree data were compatible with X-linked inheritance. This finding confirms the existence of one (or more) forms of fra(x) negative mental retardation with 'Martin Bell'-like features.
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PMID:A clinical, cytogenetic and familial study of 307 mentally retarded, institutionalized, adult male patients with special interest for fra(X) negative X-linked mental retardation. 186 91

We present a three-generation family with five retarded, abnormally appearing males and two abnormally appearing females (presumably manifesting carriers). The phenotype of the patients is different from that of all other previously described types of X-linked mental retardation (XLMR). The patients had prominent forehead, frontal bossing, hypertelorism, broad nasal tip, and anteverted nares. Chromosomes were normal including fragile X analysis. Skeletal roentgenograms were normal.
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PMID:New X-linked syndrome of mental retardation, short stature, and hypertelorism. 803 Jun 78

This paper describes a family with 10 males affected by x-linked spastic paraplegia. X-linked inheritance is rarely encountered in pure and complicated forms of hereditary spastic paraplegia. The disease was characterized by hyperreflexia, progressive spastic gait disorder, extensor plantar responses and mental retardation in all of the affected members of the family we studied. In addition to these symptoms, the older patients had cerebellar findings, severe disability and contractures. This is the 13th family manifesting x-linked spastic paraplegia reported in the literature.
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PMID:X-linked spastic paraplegia. 188 64

Five males are reported with severe X-linked arthrogryposis. Main findings are marked respiratory insufficiency and feeding problems, multiple contractures, deformities of chest and vertebral column, and typical facies. Most of these findings can be explained by a pronounced prenatal and postnatal muscle weakness. The sole living child has severe psychomotor retardation. Several female carriers show mild features (clubfeet, contractures, hyperkyphosis, and slight muscle weakness). One manifesting carrier is affected more severely (multiple contractures, mental retardation, and various dysmorphic features). Additional investigations including muscle biopsy revealed none of the usual signs of denervation, and pointed to the presence of a degenerative muscle disorder.
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PMID:A family with severe X-linked arthrogryposis. 191 20

Laser microdissection has been used to dissect material from the X-chromosome region involved in fragile-X-linked mental retardation. After dissection, single chromosome slices corresponding to this fragile site were subjected to DNA amplification using either a vector ligation method (to provide known anchor sequences) or primer oligonucleotides corresponding to the ubiquitous Alu sequences. Amplified material was then cloned or, alternately, used to screen a gridded cosmid library. Eight cosmid clones identified in this way were regionally mapped using a panel of hybrid cell lines and shown to originate from a narrow interval centered on the fragile X site. Two clones are included in the approximately 6-cM interval defined by probes RNI (DXS369, 5 cM proximal) and VK21 (DXS 296, 1-2 cM distal) and which includes the fragile site, and at least one clone contains sequences conserved across species suggestive of a gene. This method combines the focused approach of microdissection and the convenience of obtaining cosmid (rather than small-insert) clones; it may be useful for studies of other defined chromosomal regions.
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PMID:Laser microdissection of the fragile X region: identification of cosmid clones and of conserved sequences in this region. 191 12

Fragile X syndrome, an X-linked genetic disorder, is the third most common cause of mental retardation. The following is a case of a 6-year-old boy with fragile X syndrome and its characteristic cognitive and behavioral symptomatology, including attention deficit hyperactivity disorder. In addition, this child experienced initial insomnia and nocturnal enuresis, problems not previously reported with fragile X. Previous pharmacological treatment of the syndrome's behavioral difficulties and attention deficit has included stimulants, folic acid, and neuroleptics. This is the first report of the successful use of imipramine. Imipramine also improved the boy's insomnia and enuresis, whereas methylphenidate caused an overall worsening of his condition.
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PMID:Imipramine treatment of ADHD in a fragile X child. 193 2

The Fra(X) syndrome is the most common inherited cause of mental retardation. It is associated with an unusual form of X-linked inheritance where both men and women can be carriers. The "X-inactivation imprinting model" proposed by Laird et al currently offers one explanation of the unusual genetics. Recognition of clinical features and accurate cytogenetic diagnosis is important because of the prevalence of this disorder and the necessity and demand for genetic counseling. A combination of fra(X) cytogenetic studies and DNA-based linkage analysis for carrier detection and prenatal diagnosis is currently in use and is undergoing development and improvement.
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PMID:The fragile X syndrome--clinical overview. 194 6

We report on two half-brothers with the FG syndrome which is an X-linked recessive multiple congenital anomalies/mental retardation (MCA/MR) syndrome. Both patients show postnatal short stature and an altogether characteristic face consisting of droopy appearance, macrocephaly, frontal upsweep, hypertelorism, full lower lip, retrognathia, and dysmorphic ears. Moreover, since early infancy both have a tendency towards constipation, their muscle tone is low and psychomotor development is moderately retarded. Minor expression of this syndrome in the patients' mother and her two mentally retarded brothers give additional support to the X-linked nature of the condition. On the basis of the pertinent literature, a concise description of this MCA/MR syndrome with variable expression is given. Diagnostic evaluation of dysmorphic male patients with psychomotor retardation should always consider the FG syndrome which has been known since 1974 but still is inadequately recognised in the German literature.
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PMID:[FG syndrome in 2 half brothers]. 196 Dec 7

X-linked recessive hydrocephalus (HSAS) occurs at a frequency of approximately 1 per 30,000 male births and consists of hydrocephalus, stenosis of the aqueduct of Sylvius, mental retardation, spastic paraparesis, and clasped thumbs. Prenatal diagnosis of affected males by ultrasonographic detection of hydrocephalus is unreliable because hydrocephalus may be absent antenatally. Furthermore, carrier detection in females is not possible because they are asymptomatic. Using four families segregating HSAS, we performed linkage analysis with a panel of X-linked probes that detect restriction fragment length polymorphisms. We report here that HSAS, in all tested families, is closely linked to marker loci mapping in Xq28 (DXS52, lod = 6.52 at theta of 0.03; F8, lod = 4.32 at theta of 0.00; DXS15, lod = 3.40 at theta of 0.00). These data assign HSAS to the gene-dense chromosomal band Xq28 and allow for both prenatal diagnosis and carrier detection by linkage analysis.
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PMID:Assignment of X-linked hydrocephalus to Xq28 by linkage analysis. 197 56


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