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)

Two patients with partial deletion of the short arm of chromosome 10 are described. They showed most of the features observed in twenty other known patients, including growth retardation, mental deficiency, abnormally shaped skull, distinct facial dysmorphisms, cardiac and genitourinary malformations, and limbs anomalies. One of our patients also had features of the DiGeorge sequence, which has been found in five other cases with this imbalance.
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PMID:Partial deletion 10p syndrome. Report of two patients. 152 5

DiGeorge syndrome in humans is characterized by immunodeficiency, heart defects, mental retardation and facial dysmorphism; cytogenetic analysis has shown that deletions at 22q11 occur in approximately 25% of cases. To generate DNA markers from this region, we have microdissected and microcloned band q11 of human Chromosome (Chr) 22. Nineteen thousand clones were obtained from material dissected from 20 chromosome fragments. Seventeen of 61 clones analyzed (28%) were repetitive, 27 (44%) gave no signal, and 17 (28%) detected single copy sequences of which ten mapped to Chr 22. Two of these were found to be deleted in patients with DiGeorge syndrome and either monosomy for 22q11-pter or visible interstitial deletions of 22q11. These two markers are also hemizygous in patients with no visible chromosomal abnormality, demonstrating that submicroscopic deletions are common in DiGeorge syndrome patients.
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PMID:Interstitial deletions in DiGeorge syndrome detected with microclones from 22q11. 161 13

A girl with severe neonatal hypocalcaemia, thymic hypoplasia, congenital heart disease and mental retardation in combination with a partial monosomy of chromosome 22, del(22)(pter-q11.3), is reported. Nine other patients with an association between partial monosomy 22 and a DiGeorge syndrome have been reported earlier, and this combination probably constitutes a deletion syndrome similar to the Prader-Willi and the aniridia-Wilms' tumour syndromes. However, the deletion of chromosome 22 is mostly due to a translocation, with trisomy for another chromosomal segment. Such a mechanism may explain the different clinical features seen in patients with partial monosomy 22. In the present case there was an unbalanced translocation with a probable trisomy of the short arm of chromosome 20 combined with the partial monosomy 22. Cytogenetic investigation with high resolution banding techniques is indicated in patients with thymic aplasia and suspected DiGeorge syndrome.
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PMID:DiGeorge syndrome in a child with partial monosomy of chromosome 22. 271 36

High resolution prometaphase chromosome banding has allowed the detection of discrete chromosome aberrations which escaped earlier metaphase examinations. Consistent tiny deletions have been detected in some well established malformation syndromes: an interstitial deletion in 15q11/12 in the majority of patients with the Prader-Willi syndrome and in a minority of patients with the Angelman (happy puppet) syndrome; a terminal deletion of 17p13.3 in most patients examined with the Miller-Dieker syndrome; an interstitial deletion of 8q23.3/24.1 in a large majority of patients with the Giedion-Langer syndrome; an interstitial deletion of 11p13 in virtually all patients with the WAGR (Wilms' tumour-aniridia-gonadoblastoma-retardation) syndrome; and an interstitial deletion in 22q11 in about one third of patients with the DiGeorge sequence. In addition, a combination of chromosome prometaphase banding and DNA marker studies has allowed the localisation of the genes for retinoblastoma and for Wilms' tumour and the clarification of both the autosomal recessive nature of the mutation and the possible somatic mutations by which the normal allele can be lost in retina and kidney cells. After a number of X linked genes had been mapped, discrete deletions in the X chromosome were detected by prometaphase banding with specific attention paid to the sites of the gene(s) in males who had from one to up to four different X linked disorders plus mental retardation. Furthermore, the detection of balanced translocations in probands with disorders caused by autosomal dominant or X linked genes has allowed a better insight into the localisation of these genes. In some females with X linked disorders, balanced X; autosomal translocations have allowed the localisation of X linked genes at the breakpoint on the X chromosome. Balanced autosome; autosome translocations segregating with autosomal dominant conditions have provided some clues to the gene location of these conditions. In two conditions, Greig cephalopolysyndactyly and dominant aniridia, two translocation families with one common breakpoint have allowed quite a confident location of the genes at the common breakpoint at 7p13 and 11p13, respectively.
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PMID:Microdeletion syndromes, balanced translocations, and gene mapping. 305 93

Fourteen previously reported cases of the fetal alcohol syndrome (FAS) showed anomalies of brain structure varying in severity from microscopic disorganization of tissue structure, or abnormalities in neuronal or glial migration only visible microscopically, to complete or partial agenesis of regions such as the corpus callosum or cerebellum and large neuronal heteropias. The difficulty is illustrated of differentiating this type of damage, lacking in specificity and uniformity, from other syndromes of uncertain aetiology, such as De Lange, DiGeorge and Dubowitz, in at least one of which (DiGeorge syndrome) maternal alcoholism has been implicated. Similar brain damage is also seen in other conditions with known causes. In FAS and syndromes with this type of brain damage, most of the non-CNS features which make the conditions clinically recognizable may well be determined by timing or ancillary factors. Alcohol-related antenatal effects should not be identified to restrictively with FAS but should be considered in any condition of unknown aetiology with disorganization of brain structure and mental retardation.
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PMID:Range of alcohol-induced damage in the developing central nervous system. 656 85

A 34-year-old man with partial DiGeorge syndrome suffered from seizures and mental retardation from the age of three years. He was diagnosed as having primary hypoparathyroidism by the Ellsworth-Howard test at the age of 22. He was also found to have a right aortic arch. Immunological studies revealed the presence of immature T cells (CD 38+, OKT 9+), although the subsets and function of his T cells were almost normal. The facts that the cardiovascular anomaly and immunodeficiency were mild and the hypoparathyroidism was well controlled, may account for his survival to this age.
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PMID:Partial DiGeorge syndrome at the age of thirty-four. 794 42

Rhizomelic chondrodysplasia punctata (RCDP) is a sublethal autosomal recessive disorder characterized by skeletal dysplasia, microcephaly, mental retardation, congenital cataracts, joint contractures, skin changes, and failure to thrive. Prenatal ultrasound diagnosis has been reported during the second trimester of pregnancy. Prenatal diagnosis is also possible from the first trimester onwards by demonstration of peroxisomal dysfunction in cultured chorionic villous or amniotic fluid cells. In all cases reported hitherto, the prenatal diagnosis was established after the birth of a previous affected child. In contrast to these studies in pregnant multiparous women at risk for RCDP, we report on the first case of prenatal ultrasound diagnosis of RCDP at 19 weeks' gestation in a primigravida. In addition, a complex cardiac malformation associated with hypoplasia of the thymus (DiGeorge anomaly) is described.
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PMID:Prenatal ultrasound diagnosis of rhizomelic chondrodysplasia punctata in a primigravida. 799 19

DiGeorge syndrome (DGS) is a developmental defect characterized by cardiac defects, facial dysmorphism, and mental retardation. Several studies have described a critical region for DGS at 22q11, within which the majority of DGS patients have deletions. We have isolated nine cosmid and three YAC clones using previously described and newly isolated probes that have been shown to be deleted in many DGS patients. Using fluorescence in situ hybridization and digital imaging, we have mapped and ordered these clones relative to the breakpoints of two balanced translocations at 22q11 (one in a DGS patient and one in the unaffected parent of a DGS child). Our data indicate that the breakpoint in the unaffected individual distally limits the DGS critical region (defined as the smallest region of overlap), while proximally the region is limited by repeat-rich DNA. The critical region includes the balanced translocation breakpoint of the DGS patient that presumably disrupts the gene causing this syndrome.
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PMID:Molecular cytogenetic characterization of the DiGeorge syndrome region using fluorescence in situ hybridization. 840 92

DiGeorge syndrome (DGS) is predominantly caused by partial monosomy 22q11, but a subset of patients with DGS show deletions of 10p or other chromosomal abnormalities. The authors describe a 20 months old girl with DGS and a monosomy 10p bringing the number of DGS patients with this chromosomal abnormality to nine. She has a monosomy 10p13-pter and a trisomy 10q26-qter due to a meiotic recombination of a maternal inversion (10) (p13q26). The proposita's phenotype demonstrates typical features of the del (10p) syndrome which include mental retardation, abnormally shaped skull, hypertelorism, low nasal bridge, micrognathia, dysmorphic low set ears, short neck, foot abnormalities, and cardiac defect. The diagnosis of DGS was made unequivocally within the first weeks of life because of the typical features-cardiac defect, hypoplastic thymus, T-cell defect, hypocalcemia, and hypoparathyroidism. The common DGS mutation-microdeletion 22q11-was excluded by FISH analysis, and the breakpoints on chromosome 10 were mapped between D10S189 and D10S191 on the short arm and proximal to D10S25 on the long arm.
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PMID:DiGeorge syndrome and partial monosomy 10p: case report and review. 854 Jun 88

A high percentage of patients with DiGeorge syndrome and velo-cardio-facial syndrome have interstitial deletions on chromosome 22q11. The shortest region of overlap is currently estimated to be around 55 kb. Two segments of DNA from chromosome 22q11, located 160 kb apart, were cloned because they contained NotI restriction enzyme sites. In the current study we demonstrate that these segments are absent from chromosomes 22 carrying microdeletions of two different DiGeorge patients. Fluorescence in situ and Southern blot hybridization was further used to show that this locus is within the DiGeorge critical region. Phylogenetically conserved sequences adjacent to one human cell lines. cDNAs isolated with a probe from this segment showed it to contain the gene for teh human mitochondrial citrate transporter protein. Deletion of this gene in DiGeorge syndrome and velocardio-facial syndrome may contribute to the mental deficiency seen in the patients.
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PMID:Localization of the human mitochondrial citrate transporter protein gene to chromosome 22Q11 in the DiGeorge syndrome critical region. 866 94


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