Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seven patients from two different families are trisomic 2q34 leads to 2qter due to segregation of a familial t(2;8)(q34;p23). The clinical features are characteristic: microcephaly, a narrow forehead with bossing and temporal retraction, hypertelorism, palpebral fissures slanted downwards, large irides, and a very concave margin of the lower eyelid. Mental retardation is severe with a mean IQ of 50.
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PMID:[7 cases of trisomy 2q34 leads to 2qter resulting from a familial t(2;8)(q34;23)]. 30 38

The clinical manifestations and cytogenetic details of five patients with a de novo deletion of the short arm of chromosome 8, del(8)(p23), are described. Of the four surviving children all had mild mental retardation and subtle facial anomalies; three of the five had cardiac abnormalities. The clinical features seen in these patients are compared with those of three previous single case reports with del(8)(p23), and with patients described as having the '8p-' syndrome associated with del(8)(p21). The findings in these patients suggest that major congenital anomalies, especially congenital heart defects, are frequent even in small distal 8p deletions, but facial dysmorphism may be subtle and mental retardation less severe than in those with deletions associated with more proximal breakpoints. The five patients were detected within a four year period, suggesting that this deletion syndrome is relatively frequent. The possible mechanisms for the formation of terminal deletions are discussed.
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PMID:Distal 8p deletion (8p23.1----8pter): a common deletion? 161 36

At least 16 cases of inversion tandem duplications of the short arm of chromosome 8 have been reported. Structural rearrangements of chromosome 8 have made it possible to localise the gene for glutathione reductase (GSR) to 8p21.1. We report here on a 16 month old boy with mental retardation with partial trisomy 8 owing to a de novo inv dup(8)(p12----p23.1).
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PMID:Inverted tandem duplication of 8p12----p23.1 in a child with increased activity of glutathione reductase. 231 83

An adult female with sever mental retardation and dysmorphic features is described. A de novo chromosomal aberration involving 8p was found. The karyotype was 46, XX, inv dup (8) (p12----p23.1). Dosage studies with the DNA probe D8S7, which is located at 8p23----8pter, showed that the patient was monosomic for this marker. Thus the de novo rearrangement generated a duplication-deficiency chromosome. The possible mechanisms of formation of this abnormal chromosome are discussed.
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PMID:Inverted tandem duplication generates a duplication deficiency of chromosome 8p. 288 52

A five-year-old girl was referred to prometaphase chromosome analysis because of mental retardation, facial dysmorphic features suggestive of Cornelia de Lange syndrome, cleft palate and additional minor congenital malformations of the cardiac system and fingers and toes. A familial balanced translocation (3;9)(q26.1; p23) was found. The karyotype of the proposita was 46,XX,der(9),t(3;9)(q26.1;p23). Thus the patient was trisomic for 3q26.1-qter and monosomic for 9p23-pter. The unbalanced chromosome constitution was not detected by standard Q-banding analysis shortly after birth. The karyotype was misdiagnosed as 46,XX,9(p+) in the proposita and her mother, and thought to be a normal variant of chromosome 9. The repeated cytogenetic study led to the diagnosis of the translocation and to the possibility of prenatal diagnosis in the translocation carriers. A survey of 22 published cases of dup(3q) showed that nearly 60% were secondary to familial balanced rearrangements with an excess of maternally derived abnormal chromosomes 3. Red blood cell galactose-1-phosphate-uridyltransferase (GALT) activity was normal in the patient, consistent with previous assignment of the gene locus for GALT to 9p13 (Shih et al. 1982).
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PMID:Partial trisomy 3q syndrome inherited from familial t(3;9)(q26.1; p23). 365 93

The trisomy 5p (5p13----p ter) was identified by G-banding in a proband girl, whose mother was a balanced translocation carrier 46, XX, t(5;8) (p13;p23). Based on the clinical and cytogenetic findings, previously published and our own, it is possible to define a particular phenotype associated with the dup (5p), including (5p13), or the complete short arm. Patients were of similar phenotype: mental retardation, macrocephaly, hypotonia, mongoloid eye slant, low-set ears, depressed nasal bridge, macroglossia, longer fingers, epicanthus, thick cheeks.
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PMID:[A new case of trisomy 5p]. 408 94

Two female infants with de novo interstitial deletions of 8p were studied. One with a deletion from p11.21 to p11.23, and the other patient with a deletion from p11.23 to p21.3 had several clinical manifestations of the terminal 8p- syndrome. Band 8p11.23 was deleted in both patients. The clinical manifestations common to both patients included low birthweight, growth deficiency, congenital heart disease, mental retardation, dolichocephaly, low-set, malformed ears, high-arched palate, thin lips and micrognathia. Since these features may occur in most patients with chromosomal imbalance, and the terminal 8p- syndrome has hitherto been assumed to result from terminal deletions of 8p, ranging from p21.3 to p23, it is likely that these features are simply related to the chromosomal imbalance rather than to band specific imbalance of 8p11.23. The present study suggests that two different types of deletion, interstitial and terminal, are associated with still poorly defined, rather non-specific clinical features.
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PMID:Interstitial deletion of 8p: report of two patients and review of the literature. 758 43

A centromere is considered to be an essential chromosomal component where microtubule-kinetochore interaction occurs to segregate sister chromatids faithfully and acentric chromosomes are unstable and lost through cell divisions. We report a novel marker chromosome that was acentric but stable through cell divisions. The patient was a 2-year-old girl with mental retardation, patent ductus arteriosus, and mild dysmorphic features. G-banded chromosome analysis revealed that an additional small marker chromosome was observed in all 100 cells examined. By the reverse-chromosome-painting method, the marker was found to originate from the distal region of 8p, and a subsequent two-color FISH analysis with cosmid probes around the region revealed that the marker was an inverted duplication interpreted as 8pter-->p23.1::p23.1-->8pter. No centromeric region was involved in the marker. By FISH, no alpha-satellite sequence was detected on the marker, while a telomere sequence was detected at each end. Anti-kinetochore immunostaining, using a serum from a patient with CREST (calcinosis, Raynaud syndrome, esophageal dismotility, sclerodactyly, and telangiectasia) syndrome, showed a pair of signals on the marker, which indicated that a functional kinetochore was present on the marker. The analysis of this patient might suggest the possibility that an ancient centromere sequence exists at distal 8p (8p23.1-pter) and was activated through the chromosome rearrangement in the patient.
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PMID:A stable acentric marker chromosome: possible existence of an intercalary ancient centromere at distal 8p. 797 81

A region-specific library for human chromosome 2p23-p25 was constructed using microdissection and polymerase chain reaction (PCR)-mediated microcloning techniques. This library is large, comprising 300,000 recombinant microclones. The insert sizes range between 50-600 base pairs (bp) with a mean of 200 bp. About 50%-60% of the clones contain unique or very low copy number sequence inserts as determined by their weak or no hybridization to total human DNA. A subset of 48 microclones that did not hybridize to total human DNA after colony hybridization was analyzed, and 26 (54%) clones were shown to contain single-copy inserts and hybridize to human chromosome 2 DNAs, indicating that they are human chromosome 2 specific. The human genomic fragments identified by these clones after cleavage with HindIII have also been characterized. The single-copy microclones were used to analyze an interstitial deletion in the 2p23.3-p25.1 region--46,XY, del(2) (pter-->p25.1::p23.3-->qter)--previously reported in a patient with severe growth and mental retardation and multiple anomalies. Of the 26 microclones analyzed, 14 clones were mapped to the deletion region. The availability of the 2p23-p25 region-specific library and the probes derived from the library should be valuable for fine structure physical mapping analysis and the cloning of disease-related genes localized to the region. These studies also demonstrate the efficiency with which useful probes can be quickly generated for genome studies and for positional cloning.
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PMID:A region-specific microdissection library for human chromosome 2p23-p25 and the analysis of an interstitial deletion of 2p23.3-p25.1. 816 34

A patient is described with partial trisomy 9p and partial monosomy 8p due to a maternal translocation (t(8;9)(p23;p13)). The clinical phenotype is compatible with the partial trisomy 9p syndrome. This is a clinically recognizable syndrome with mental retardation as a constant feature. Little is known about the outcome and level of functioning of patients with this condition. We present the follow-up of a patient with partial trisomy 9p who has been regularly examined from birth until age 10 years.
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PMID:Follow-up of a patient with partial trisomy 9p and partial monosomy 8p; description of physical and psychosocial development. 865 90


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